After almost 7 years with my Olympus EM1 mk2 in a Nauticam housing it is time to upgrade. Moving on to the OM1 mk2 would be the logical progression but because I will be diving for about 5 months every year from now on I can work with a much larger budget than in the past and size/weight is a bit less important. That means I am also looking at full frame and in particular the A7R V. That said, my underwaterphotography focus is on fish portraits with a more scientific than artistic interest and the image quality of my current camera is already plenty enough. The same applies to other well known (dis)advantages of cost, size/weight, video specs, readout speed/rolling shutter, ..., none of those are critical to me. Another factor to consider is that I haven't used lenses wider than 24mm (FF) in the past 2 decades and rarely go lower than 35mm (I do have a WA wet lens for occasional images of fish habitats).

 

I thought it might be fun to consider pros & cons in this context where my priority is to maximize the chance of getting a good image rather than maximizing my ability to capture the perfect image. Below I list a few no-brainer reasons to prefer the A7R V, some that look good on paper but may not be that important in practice, and some where the OM1 has unique advantages. Ideally some of you have used both systems or have tips relevant to these issues.

 

No-brainer advantages for the A7R V (and other high resolution FF cameras)

• For fast and erratically moving fish you can't make them fill the frame without too high risk of cutting off some parts. With a 61Mpixel FF sensor I can frame the fish to cover the central part, crop as needed, and still end up with an image of a size similar to the 20Mpixel m43 sensor. So 'croppability' is a big plus of FF sensors for me.
• With a m43 sensor I can rarely shoot a fish at 1:1 magnification because few fish are small enough to fit the 17mm width of the sensor. The FF sensor size is a better match to the typical size of small gobies etc.
• For skittish fish you often can't maximize magnification by getting closer. So, at the closest distance you can achieve, you maximize magnification by using a longer focal length (or a teleconverter). This is easier on FF where you typically work with longer lenses already and you can get that magnification without making the field of view so narrow that it becomes impractical.
• The higher Mpixel count gives greater resolving power (if you don't close the aperture too much).

 

A7R V advantages of unknown practical benefit

• The latest generation of Sony cameras (and Canon?) are supposed to have superior continuous AF, subject detection and focus tracking. But the OM1 also has AI subject detection and AF improvements over previous models. Has anyone used both systems? If so, how much better is the sony AF compared to the OM1 mk2?
• The A7R V has a large high resolution viewfinder (0.9x, 9.4MPx) but the OM1 mk2's 0.82 (FF equiv.) 5.7Mpx viewfinder is quite impressive and much better than my current 0.74 (FF equiv.) 2.4Mpx finder.

 

OM system benefits

• Olympus cameras are the only ones I know of that allow me to very accurately measure objects in images (about 1% accuracy, blog to be posted soon). That is important for my scientific use of the images.
• The Oly 12-50mm powerzoom kit lens is a very practical underwater lens. You can zoom it without need for a zoom gear (it seems other camera brands don't offer that feature for their powerzoom lenses). It's 24-100mm range, FF equiv., and focus distance is very practical, it does not extend when zoomed or focused, and it can be used in the same port as the 60mm macro lens. It also has a special 'macro mode' that focuses down to 20cm and creates a 0.36x image with a fixed 43mm focal length. But I don't use that.
• OM systems recently came out with an autofocus 90mm F3.5 macro lens that can do 2:1 magnification. Cool, but the magnification is not really that useful for fish.

 

For lenses, the Sony 90mm F2.8 macro will be a good and likely superior replacement for the Oly 60mm F2.8 macro lens.

 

The Sony 24-105mm F4 would be a logical, and optically superior, lens to the Oly 12-50mm. However, Nauticam's port chart does not include a zoom gear for it and there is no discussion about it's use underwater on this forum. There has been discussion on waterpixel about using the Canon RF 24-105mm F4, for which Nauticam does make a zoom gear. The Sony lens actually focuses closer (38cm vs 45 for Canon) and reaches higher magnification (0.31x vs 0.24 for Canon). Both lenses extend when zooming, so why is the Sony lens not considered for underwater use? It would be a nice top-side lens as well.

 

 

36 minutes ago, Biodives said:

• With a m43 sensor I can rarely shoot a fish at 1:1 magnification because few fish are small enough to fit the 17mm width of the sensor. The FF sensor size is a better match to the typical size of small gobies etc.
• For skittish fish you often can't maximize magnification by getting closer. So, at the closest distance you can achieve, you maximize magnification by using a longer focal length (or a teleconverter). This is easier on FF where you typically work with longer lenses already and you can get that magnification without making the field of view so narrow that it becomes impractical.

 

I'm not sure I understood these two points.

Far be it from me to get into an FF/Crop sensor war 😇

I have owned both cameras and can make a case for either one, since I have been shooting Sony since A7 II let me comment on one lens choice. With out doubt the 90mm macro would be my lens of choice for 1:4 to beyond life-size.

 

I chose to go with the Sony FE 20-70mm F/4 as the all purpose fish lens. It focuses to 25cm and has magnification of 0.39X (1:2.6) 24-105 max magnification is 1:3.2. Both of these lenses are supported by Marelux using a 180mm dome with 50mm extension for 20-70 and 70mm for 24-105mm they also work in the 230mm dome port.

 

Nauticam lists 20-70 max performance with the 250mm dome but also lists domes down to 180mm. I don't see the 24-105 listed on the Nauticam charts perhaps because of its much longer extension.

 

Turtle at 20mm, Razorfish at 70mm and Batfish at 45mm to give you some idea of the zoom range.

 

I had (have) an EM1 ii i and now a Sony A7Rv. I just intended to sell the Olympus but have been hesitating. Both are really good but it is easy to underappreciate the Olympus.

 

I have an Isotta housing and last year there was not a confirmation from them that they would make a housing for the OM1. (They do now.) I also wanted as high a resolution as possible as I am trying to take survey pictures of substrate and count coral recruitment. Hence my change to Sony.

 

I can't see much benefit in the Sony in your circumstances except for the ability to crop, which could be significant.

 

I am not sure about Nauticam but with the 102mm diameter port system on Olympus in Isotta I never have to remove a port to get the camera out of the housing even if using larger diameter lenses. I have found the 12-40 pro (thanks Chris Ross for the prompt) really good to use for medium size fish. I was using it with a flat port and extension that I had anyway and just the range from 40mm down to about 25 to 30mm. I assume it is considerably sharper than the 12-50. I was also using the 60mm macro. 

 

For me I really like versatility of the A7Rv (in APSC mode it has the same pixel pitch and resolution as the A6700). The autofocus is better but I didn't find it an issue on the EM 1ii. I tend to use back button and spot focus a lot as I am worried the focus will jump off my target. I've not found the AI on the Sony useful for fish so far. I have the 90mm and Canon 8-15mm fisheye and the Sony 28-60 which is probably not great for fish on its own (I have only tried it once - am waiting for a WWL-1 to arrive). I have not looked at the spec but assume the 28-60 has too long a minimum focus distance to be fun to use on its own. 

 

The viewfinder is very good. I have a 45 degree viewfinder on the EM 1 ii housing but haven't bothered using it yet on the Sony housing ( I very rarely use the LCD due to bright sunlight)

 

The smaller and lighter lenses are something I miss when handling the camera on a boat.

When I look back through my fish photos I can't tell by looking which ones are taken with the Olympus and which ones with the Sony.

 

One thing about the Sony A7Rv is that, if I take a photo and it is not as sharp or detailed as I want, I now know it is is my fault and not the camera!

 

 

 

 

 

Just to tack on to John’s comment about sharpness, if you do move to the a7rV, be aware you may be disappointed initially at the details or focus in your images.  This is not because they are lacking, but rather the correct focus point becomes much more critical due to the ultra high resolution.  I know I had a bit of learning curve when I switched from a lower res format to the 61MP.  When you nail the focus, the detail is truly amazing! 

 

1 hour ago, John E said:

the Sony 28-60 which is probably not great for fish on its own (I have only tried it once - am waiting for a WWL-1 to arrive)

You are correct, the 28-60 is nothing special on its own.  It’s the WWL that really makes it super versatile.  You’ll love it once it arrives! 

Edited March 21, 20241 yr by ChipBPhoto

And you have to love the fish that need a fisheye lens. This reticulated whipray photo was taken on an EM 1ii with the Olympus 8mm.

 

 

I would ask what you are missing out on with your current system , cropability is the only one that seems to stand out to me.  Having said that I get plenty of perfectly usable images with up to 50% cropping out of the Olympus. 

 

I have used the EM-1 MkII for quite some time and now I'm using the OM-1 initially on land and now have housed it underwater.  I've found the AF to be very good on both cameras, but the OM-1 is certainly a step up in AF capability.  For example at high magnification on the 90mm macro it would lock focus where the EM-1 MkII could not, probably pointing to improved low light focus capability.   But it seems AF is not a limiting factor with the EM-1 MkII for your uses?

 

I'm not sure I get your argument on this item though:

Quote

Quote

For skittish fish you often can't maximize magnification by getting closer. So, at the closest distance you can achieve, you maximize magnification by using a longer focal length (or a teleconverter). This is easier on FF where you typically work with longer lenses already and you can get that magnification without making the field of view so narrow that it becomes impractical.

 

Field of view is field of view, you just need to have the same equivalent focal length on both systems, to get the same reach and field and ability to frame comfortably.

 

If 80mm full frame equivalent is enough for you the 12-40 olympus lens is very sharp right from wide open and focus is extremely snappy, it just locks on and as a bonus will focus very close allowing about 0.3x focusing right on the dome.  Macro lenses as a rule will generally be slower if for no other reason that they have a very wide focal range to work through.  the 12-45 f4 is a slightly smaller package which has similar to the 12-40.

 

Regarding resolution, underwater shooting through a significant amount of water is a great leveller.  What ultimately sets your resolution is pixel size and the OM-1 20MP sensor has 3.3 micron pixels while the 61MP Sony has 3.6 micron pixels, so pretty much a wash for pixel size with a small advantage to the m43 sensor.

 

The other consideration is depth of field the same fish comfortably framed the same way on full frame has less depth of field than a m43 frame.  You can shoot m43 at f8 and get the same depth of field as full frame at f16.   This also means with the same pixel size you are deeper into diffraction in general on full frame.  In general you will be shooing with a wider f stop on m43 and this means that you need less strobe power which is a consideration if you are backing off and using longer focal lengths for skittish fish meaning faster recycle times.   Depth of field may be important for example in trying to do ray counts on a small fish that refuses to let you get parallel to it.

 

Diffraction starts at f7.1 on a 61 MP sensor but you do need to stop down quite a bit more before it starts to impact resolution the difference is you could probably shoot at f5.6/8 on m43 all the time and be effectively diffraction free while full frame you might be f11 at minimum.    This is probably more of a leveller between the formats than a clear advantage for m43.  To me this means why go to the expense of FF?

Thanks for all the feedback.

 

It is good to see that Marelux supports the 24-105mm F4. All recommended configurations use dome ports but as long as the flat ports have a wide enough diameter it should fit, ideally behind the 90mm macro port with extention tube (the 24-105mm F4 has a 5mm greater diameter than the 90mm macro). If there is distortion or vignetting at the wide end that is acceptable for me.

 

The Oly EM1 mk2 AF is not good enough for me to track wrasse, damselfish and all the other erratically moving small reef fishes that interest me. In many/most cases, when you get the camera to focus on the fish in C-AF mode it will jump back to the coral in the background when the fish makes a few sharp turns and you can't keep it under the focus point. If the new AI-assisted focus systems are sticky enough to track fish with a much higher hit rate, that would be a major benefit for me.

My alternate focusing method is to focus on a solid object at the distance I hope/expect to be able to take my shot and then wait till the fish shows up at the right distance and pose, using the viewfinder to judge focus. So viewfinder quality is also something I care about. I do have a 45 degree magnifying viewfinder but mostly use it for stationary subjects as I haven't mastered the spatial awareness needed to hover very close to the reef with my eye on that type of viewfinder.

 

Discussions about sensor size typically involve depth of field (DOF), resolution, equivalent focal length and aperture, etc. I prefer to see these as properties of the image projected by the lens and not of the sensor. In other words, at the same distance a lens with a given actual focal length and aperture setting has the same magnification, DOF and resolution, whether attached to a crop or FF camera. With this perspective you can look at different outcomes:

• with the same focal length, aperture and distance, the benefit of FF is that you can image a scene that is twice as large with the same resolution and DOF. Which is the same as saying that m43 represents an enforced 2-fold crop of the FF image. This is important to me.
• With m43 you can half the focal length or increase subject distance to match the scene captured by FF but now the latter corresponds to a 2-fold higher magnification (the physical size of the image projected on the sensor).
  • If the two sensors have the same pixel size a FF pixel will correspond to a feature that is half the size in the scene. So you get up to twice the resolution. This is important to me.
  • If the two sensors have the same number of pixels then the FF sensor will have a 4 times larger area per pixel, giving greater dynamic range and lower noise. This is not important to me hence less interest in the A7 IV.
  • With higher magnification comes shallower DOF. This is desired by some for artistic reasons but is not important, or mostly disadvantageous to me.
• Less DOF is not a disadvantage of FF because it is just the price you pay to get higher resolution.
  • To get the same resolution on m43 you simultaneously reduce DOF back to the same level as FF.
  • You can restore DOF on FF by stopping down the aperture. That will make the strobe work harder compared to m43 but not an issue if your strobe has enough power. Moreover, if you use double the focal length on FF you can increase the aperture by two stops without having more diffraction effects than m43 (in both cases the physical diameter of the aperture will be the same).
  • Diffraction sensitivity does depend on pixel size. The larger the pixel, the more resolution loss due to diffraction you can tolerate before it becomes noticeable. This is not an advantage because it just means you can't record the full resolution the lens can deliver. But the 61Mpx FF sensor pixels are similar to the 20Mpx m43 sensor so not too much difference.

I am sure there is more to say about in the FF vs crop discussion and different ways to look at it. But this is the way that works for my interests.

 

 

 

 

 

 

3 hours ago, Biodives said:

Thanks for all the feedback.

 

It is good to see that Marelux supports the 24-105mm F4. All recommended configurations use dome ports but as long as the flat ports have a wide enough diameter it should fit, ideally behind the 90mm macro port with extention tube (the 24-105mm F4 has a 5mm greater diameter than the 90mm macro). If there is distortion or vignetting at the wide end that is acceptable for me.

 

 

Using the 24-105 behind a flat port would render the lens all but useless. When extended to 105 it only focuses to 1:3.2 as soon as you start to retract towards the 24mm end of the lens all you will be seeing is a circular image because it will vignette on the inside of the port. It has a longer extension than the 20-70 F/4 and other 24-70 lenses which also do the same thing inside a flat port. This is why it is paired with a dome and not a flat port. In a macro port Marelux or Nauticam the 90mm macro is a much better choice because it is internal focus and will go from 1:1 to infinity.  

 

5 hours ago, Biodives said:

Thanks for all the feedback.

 

The Oly EM1 mk2 AF is not good enough for me to track wrasse, damselfish and all the other erratically moving small reef fishes that interest me. In many/most cases, when you get the camera to focus on the fish in C-AF mode it will jump back to the coral in the background when the fish makes a few sharp turns and you can't keep it under the focus point. If the new AI-assisted focus systems are sticky enough to track fish with a much higher hit rate, that would be a major benefit for me.

 

• With m43 you can half the focal length or increase subject distance to match the scene captured by FF but now the latter corresponds to a 2-fold higher magnification (the physical size of the image projected on the sensor).
  • If the two sensors have the same pixel size a FF pixel will correspond to a feature that is half the size in the scene. So you get up to twice the resolution. This is important to me.
  • If the two sensors have the same number of pixels then the FF sensor will have a 4 times larger area per pixel, giving greater dynamic range and lower noise. This is not important to me hence less interest in the A7 IV.
  • With higher magnification comes shallower DOF. This is desired by some for artistic reasons but is not important, or mostly disadvantageous to me.
• Less DOF is not a disadvantage of FF because it is just the price you pay to get higher resolution.
  • To get the same resolution on m43 you simultaneously reduce DOF back to the same level as FF.
  • You can restore DOF on FF by stopping down the aperture. That will make the strobe work harder compared to m43 but not an issue if your strobe has enough power. Moreover, if you use double the focal length on FF you can increase the aperture by two stops without having more diffraction effects than m43 (in both cases the physical diameter of the aperture will be the same).
  • Diffraction sensitivity does depend on pixel size. The larger the pixel, the more resolution loss due to diffraction you can tolerate before it becomes noticeable. This is not an advantage because it just means you can't record the full resolution the lens can deliver. But the 61Mpx FF sensor pixels are similar to the 20Mpx m43 sensor so not too much difference.

 

Did you ever use C-AF + TR on the EM-1 MkII? I found it reasonably good at holding focus on things swaying in the surge.  I've found the same function not quite so good on the OM-1, but the AI helps in certain situations. I'll have a try shooting with subject recognition if I can find suitably wriggly subjects on my next dive.  I'm first to admit I don't do much fish shooting particularly with difficult subjects, plenty of small subjects swaying in the surge though.

 

I'm not sure I follow your argument regarding magnification.  If you match the scene by which I mean the subject takes up the same % of the frame then the magnification is lower on m43, because you are further away using the same focal length to allow the fish to fill the same amount of the frame.  So if you have a fish that covers 9mm on the sensor in m43 you have to make it cover 18mm on the sensor in full frame by getting closer or using more focal length. 

 

Certainly if you match the composition in full frame you'll have twice the pixels representing the subject, but achieving that seems like it may be easier said than done.  A more likely scenario seems to be the extra real estate gives you more wriggle room to frame your subject. 

11 hours ago, Phil Rudin said:

Using the 24-105 behind a flat port would render the lens all but useless. When extended to 105 it only focuses to 1:3.2 as soon as you start to retract towards the 24mm end of the lens all you will be seeing is a circular image because it will vignette on the inside of the port. It has a longer extension than the 20-70 F/4 and other 24-70 lenses which also do the same thing inside a flat port. This is why it is paired with a dome and not a flat port. In a macro port Marelux or Nauticam the 90mm macro is a much better choice because it is internal focus and will go from 1:1 to infinity.  

 

 

Thanks Phil, this will be critical to test. If I loose the 24-35mm part of the zoom range that is not a deal breaker. If I loose everything below 50mm then it isn't worth it and it may even push me to stay with m43 as 24-70mm isn't long enough on FF.

 

The Oly 12-50mm doesn't have this problem because it uses internal zoom and focusing. But I can also use the much shorter Oly 25mm F1.8 in the 60mm macro port without vignetting so I hope a large part of the 24-105mm zoom range will remain available in a flat port.

12 hours ago, Chris Ross said:

Did you ever use C-AF + TR on the EM-1 MkII? I found it reasonably good at holding focus on things swaying in the surge.  I've found the same function not quite so good on the OM-1, but the AI helps in certain situations. I'll have a try shooting with subject recognition if I can find suitably wriggly subjects on my next dive.  I'm first to admit I don't do much fish shooting particularly with difficult subjects, plenty of small subjects swaying in the surge though.

 

I'm not sure I follow your argument regarding magnification.  If you match the scene by which I mean the subject takes up the same % of the frame then the magnification is lower on m43, because you are further away using the same focal length to allow the fish to fill the same amount of the frame.  So if you have a fish that covers 9mm on the sensor in m43 you have to make it cover 18mm on the sensor in full frame by getting closer or using more focal length. 

 

Certainly if you match the composition in full frame you'll have twice the pixels representing the subject, but achieving that seems like it may be easier said than done.  A more likely scenario seems to be the extra real estate gives you more wriggle room to frame your subject. 

 

I haven't used C-AF + Tracking recently as in the past I found it to be not that useful. For fusiliers or other plankton feeding fish that swim some distance from the reef it may be great because it is clear what the camera should focus on. But most of my fish are on, in, under or around coral and then the camera often ends up focusing on the coral.

 

It seems you did get the magnification argument. To get a fish to cover the same %age of the frame the projected image will be twice as large on the FF sensor compared to m43. When pixel sizes are similar you will get many more pixels to cover the subject and thus can record higher resolution features.

 

Achieving this shouldn't be hard, just use a double focal length lens on FF and shoot from the same distance as you would do on m43. In cases where framing is a challenge, and perhaps make it easier to keep the subject in the center of the frame when using C-AF + TR, you can opt to not use a longer focal length lens and optimize for wider field of view instead of magnification. Either way is a win for me.

 

If you are mostly interested in the entire scene then you may not notice the extra resolution unless you start pixel peeping. But for my use cropping, or zooming, to look at details is important. Important enough to switch systems and give up some nice features from Olympus I don't know yet. In the past cost and to a lesser extend size would dominate my decision. Now that I am retired and can make 5-month dive trips to study coastal fish biodiversity it makes sense to get what is best for that purpose.

 

 

Edited March 23, 20241 yr by Biodives

50 minutes ago, Biodives said:

 

I haven't used C-AF + Tracking recently as in the past I found it to be not that useful. For fusiliers or other plankton feeding fish that swim some distance from the reef it may be great because it is clear what the camera should focus on. But most of my fish are on, in, under or around coral and then the camera often ends up focusing on the coral.

 

It seems you did get the magnification argument. To get a fish to cover the same %age of the frame the project image will be twice as large on the FF sensor compared to m43. When pixel sizes are similar you will get many more pixels to cover the subject and thus can record higher resolution features.

 

Achieving this shouldn't be hard, just use a double focal length lens on FF and shoot from the same distance as you would do on m43. In cases where framing is a challenge, and perhaps make it easier to keep the subject in the center of the frame when using C-AF + TR, you can opt to not use a longer focal length lens and optimize for wider field of view instead of magnification. Either way is a win for me.

 

If you are mostly interested in the entire scene then you may not notice the extra resolution unless you start pixel peeping. But for my use cropping, or zooming, to look at details is important. Important enough to switch systems and give up some nice features from Olympus I don't know yet.

 

 

Yes just a matter of finding the right lens!   I get the impression the tracking systems seem to work better on distant subjects like flying birds with telephotos rather than close in and busy.  I'm wondering if you could somehow squeeze the Olympus 12-100 lens into a housing.  Then you could stand back quite a ways, the 77mm OD would be tight for the Nauticam N85 port system.   There's also the OM-1 Mk2 coming out which mainly claims improved AF and tracking features.

1 hour ago, Chris Ross said:

Yes just a matter of finding the right lens!   I get the impression the tracking systems seem to work better on distant subjects like flying birds with telephotos rather than close in and busy.  I'm wondering if you could somehow squeeze the Olympus 12-100 lens into a housing.  Then you could stand back quite a ways, the 77mm OD would be tight for the Nauticam N85 port system.   There's also the OM-1 Mk2 coming out which mainly claims improved AF and tracking features.

 

I dive about 5 months in the October - April period each year (just in the airport at the end of my first such trip). So I have time to consider all options before locking into new gear for the next 5-10 years. I am excited to see what, if anything, else becomes available, especially lenses and lens support by housing makers.

 

I would expect (distant) birds in the sky to be easy to track, like fish against a blue ocean background. And even between trees, birds may work better than fish because the AI chip is trained on birds and locks onto the eye. But I have read people being impressed by the Sony camera's ability to recognize and stick to the eye of fish, even if the fish is partly turned away from the camera. So I think there is hope that these new AI-assisted AF systems are noticeably better then what I have now.

 

The Oly 12-100mm F4 is interesting with its combination of long focal length and close focusing but the vignetting issue Phil pointed out must be more of a problem when dealing with such a large zoom range. Once I get back home I can visit my camera store to check out some of these lenses in the flesh.

I changed from Oly EM1II to Sony A7R5 about a year ago and do not regret it, I really enjoy the camera...

 

The big pluses, to my experience, are the 14-bit raw files for postprocessing (the sensor delivers data that are really worth to be digitized at 14 bit, it is not just a matter of the A/D converter) and the 61 M-pixels (for cropping)...

 

C-AF&tracking on the EM1II was already o.k, but is better now on A7R5. In addition, subject recognition (mostly eyes) works very well sometimes, but not always. A7R5 AF is probably the best available today, but a camera with perfect AF still has to be built...

 

The big disadvantage of FF vs MFT is the lens choice and size (both WA and macro). The lens choice for A7R5 is o.k., but not superb as it is for MFT. An example: I am currently in Providencia/Columbia with Lisi, my wife. The main subject here are Carribean reef sharks, that come quite close to photographers. I use Sony 28-60mm/WACP-C with A7R5, she uses Tokina 10-17mm/DP100 with 1x glassless adapter. We both have 2x Z330. Very similar range of AOVs, but her rig is substantially smaller (it is like a childrens's rig compared to a rig for adults 😋...). I envy her a little during transportation, but not so when it comes to postprocessing in LR...

Another example: EM1II with Pana 45mm macro (45mm is the equivalent lens to the Sony 90mm macro, not the (better) Zuiko 60mm) gives similar results compared to A7R5/Sony 90mm/SMC-1. The EM1II/45mm rig is very small and handy, while the A7R5/Sony 90mm/SMC-1 is a monstrum. When I say comparable results, I mean just the size of a critter at 1:1 (=1:2 for FF) that you can photograph to fill the frame. The sharpness and brilliance of FF is clearly better compared to MFT...

 

But here are other examples also: I was using the Canon 8-15mm with 140mm dome and 1x glassless adapter with EM1II. I use the same lens with same dome on A7R5 now and the rig sizes are pretty the same, but the AOVs are very different (too much for the reef sharks here, they do not come close enough. I could have left the Canon 8-15mm and the 140mm dome at home, but who knows for sure in advance?)...

For normal range I used Zuiko 12-40mm with 170mm dome on EM1II. Now I use Sony 20-70mm with 170mm, what gives similar sized (but already substantially large) rigs, but better zoom range with Sony 20-70mm (and even better IQ compared to the already brilliant Zuiko 12-40mm)

 

=> At the end I believe that there is no advantage without disadvantage and vice versa...☺️

 

 

Wolfgang

Edited March 23, 20241 yr by Architeuthis

I visited my local camera store yesterday to finally get my hands and eyes on some cameras. Reading about handling isn't the same as actually handling the cameras. For instance, I had read many times that FF lenses are much larger but I wasn't prepared for how much larger they were. Similarly, I was surprised how little difference there is in body size. When comparing viewfinders the Sony A7C R was noticeably poorer than the other two so that camera is no longer a candidate.

 

One concern with Sony cameras for me is whether I can determine the length of fish from an image. To check that out I took a series of images of a ruler. I just did some stats on the EXIF information and it turns out that the reported focus distance correlates very well with the observed image width based on the ruler. It is actually easier than on my current Olympus camera because it is a linear relationship, as shown below.

 

I also tried it on the 24-105mm zoom lens at a few different focal lengths and it seems to work there as well. Hopefully that means all modern Sony lenses have an accurate distance decoder.

 

So, for now both the OM-1 and A7R V remain in the running to be my next camera with the latter becoming more interesting.

Yes, any FF will be substantially larger than an m4/3.  And you are right, there is no way to gauge the real size without you experiencing it first hand.  It’s great that you had that opportunity.  It also weeded out one you now know you do not want.  
 

I had the original Oly E-M1 m4/3 and loved the size, especially regarding the lenses.  They were tiny and much cheaper by comparison.  The entire system is also substantially smaller when you add the housing and port, as you already know.  
 

For me, I found I wanted a larger sensor and a greater ease in creating shallow DoF.  As a result I bit the size bullet for a FF and have been happy with the results.  I also have been very happy with the WWL/WACP with the 28-60.  This allows CFWA through midrange fish portraits.  The ultra close focus ability of it also allows almost a pseudo macro ability in a pinch.  The 90 is super sharp for macro.  I’ve also found the focus to be very accurate.  That’s just me and my personal priorities.  I can attest that the a7rV is a beast of a system with a long lifespan ahead of it, but again that’s just my feeling.

 

Bottom line, there will be a ton of considerations, calculations, and opinions others will share.  It honestly comes down to what fits your personal needs the best and what feels best in your hands.  Either of the options you are considering will produce excellent results.  I have no doubt you will be able to gauge the distances you referenced with either system once you’ve become accustomed to it.  With these two choices, sensor size, overall size of the rig, and perhaps cost will often be the factors that will help you ultimately decide.  

Edited March 28, 20241 yr by ChipBPhoto

5 hours ago, Biodives said:

So, for now both the OM-1 and A7R V remain in the running to be my next camera with the latter becoming more interesting.

This video may be interesting if you go for the Sony….

 

 

I had seen that video and the one they made for m43 lenses (where they don't even mention my favorite 12-50mm kit lens). The most interesting bit in the Sony video was that the 100mm EF and 60mm EF-S Canon macro lenses can both apparently work with autofocus, apperture control and distance communication with the metabones adapter. To my surprise the EF-S lens supposedly even covers the FF sensor (but perhaps only when focusing very close?). If so, the adapter is worth it just to use the 60mm Macro.

 

They don't comment on performance of the 100mm macro on a Sony body but there is a 4 year old youtube video comparing the Sony 90mm vs Canon 100mm macro with a metabones adapter

 

 

Apart from video autofocus, the canon lens is working very well. From the Metabones website, with newer Sony bodies and the 5th generation adapter video AF-C should now also work. However, Wolfgang ("architheutis") posted on DPreview about his experience with exactly this configuration (100mm macro, A7R V, and metabones mark V) and he ended up getting the Sony 90mm macro. Others suggest the Sigma MC-11 adapter works better. More to test but, since this will be a workhorse lens, going native is probably best.

 

The UW Sony lens video mostly focuses on WA and macro and doesn't really go into the intermediate or longer range as it is of less interest to most divers. For me it does because I want to image fish of different size without having to back off too far. For zooms, they do mention the Sony 20-70mm F4 but not the 24-105mm F4 which for me is a more interesting focal length range. For primes, they mention the Sigma 150mm F2.8 macro which I looked at in my Canon 20D DSLR days but never bought. There is an even more extreme 180mm F3.5 'L' macro lens from Canon. I fear these are too specialized to warrant their cost but with DSLR users switching to mirrorless they should become more widely available as second hand options. Just checking the internet, the 150mm macro seems to go for only 300-400 Cnd$. Maybe that would be a fun experiment some day in the future. Or perhaps by then Sony has come out with a native longer focal length macro lens.

i can comment on the Canon 100mm IS macro with Metabones adapter on Sony A7R5. It works and I was using it, but AF is much worse than with the native Sony 90mm macro. C-AF& tracking works very well with the Sony 90mm, but performance is poor with the adapted Canon. IQ with Sony is at least as good as with the Canon. I finally have sold the Canon. Of course more native, well working, macro lenses for Sony would be desirable, but this is not in sight at present...

 

I have the 20-70mm Sony and use it with Zen domeport DP170 (170mm). IQ is very good and the focal range is very good as well. Especially the 20mm that already provide reasonable WA and the possibility to zoom in (70mm is enough, you cannot zoom in endless in water, IQ suffers with distance). I think the 24-100mm is not well suited for UW: 24mm is substantially less WA as 20mm and 100mm is too much. You must not forget that you need a domeport, not a flatport, to get good IQ at 24mm. With a domeport you cannot use 100mm very well for closeup as the domeport is big. In addition, the 24-100mm is not a macro lens. Better use a dedicated lens as Sony 90mm macro with flatport for photos with long focal length...

 

Wolfgang

Edited March 29, 20241 yr by Architeuthis

21 minutes ago, Architeuthis said:

i can comment on the Canon 100mm IS macro with Metabones adapter on Sony A7R5. It works and I was using it, but AF is much worse than with the native Sony 90mm macro. C-AF& tracking works very well with the Sony 90mm, but performance is poor with the adapted Canon. IQ with Sony is at least as good as with the Canon. I finally have sold the Canon. Of course more native, well working, macro lenses for Sony would be desirable, but this is not in sight at present...

 

I have the 20-70mm Sony and use it with Zen domeport DP170 (170mm). IQ is very good and the focal range is very good as well. Especially the 20mm that already provide reasonable WA and the possibility to zoom in (70mm is enough, you cannot zoom in endless in water, IQ suffers with distance). I think the 24-100mm is not well suited for UW: 24mm is substantially less WA as 20mm and 100mm is too much. You must not forget that you need a domeport, not a flatport, to get good IQ at 24mm. With a domeport you cannot use 100mm very well for closeup as the domeport is big. In addition, the 24-100mm is not a macro lens. Better use a dedicated lens as Sony 90mm macro with flatport for photos with long focal length...

 

Wolfgang

I agreee with everything Wolfgang said!  Ironically, I was just typing the same answers, but he beat me to it. 😂

 

To add a bit more, yes, the EF-S 60 does work with the Metabones on the FF.  There is, however, vignetting.  This is not an issue for blackwater, but will show in daylight scenes.  Unless you need a wider macro, I have found the Sony 90 to be the best choice.  I too had the EF 100 and found the 90 to be a much better solution with the newer bodies.
 

Continuing with macro, adding an SMC-1, as example, to the Sony 90 will most likely be a more versatile and better overall solution than using a 150 or longer macro.  Again, the more water between the lens and the subjects means lower overall image quality.  The exception here would be if you are working with a tiny and super shy subject that requires greater distance to simply make the image.  (Very rare)

Edited March 29, 20241 yr by ChipBPhoto

Regarding MFT, I have used EM5II and EM1II for years. I know the 12-50 lens behind a flatport was very popular, but cannot say anything from own experience about his lens. I never purchased it, because I cannot imagine that 12mm behind a flat port gives decent IQ. Same with the 50 macro capapbilty. The Pana 45mm and Zuiko 60mm are excellent macro lenses in comparison. I believe the 12-50mm is a Jack of all trades, but not really good in any category. Better to prepare a dedicated rig and have really good IQ...

 

I have used the 12-40mm lens behind Zen DP170 for fish portraits and it is excellent (But now, with A7R5, the 20-70mm is even better, as I have 20mm (instead of 24mm equivalent)...

 

 

Wolfgang

 

Wolfgang,

"The UW Sony lens video mostly focuses on WA and macro and doesn't really go into the intermediate or longer range as it is of less interest to most divers. For me it does because I want to image fish of different size without having to back off too far. For zooms, they do mention the Sony 20-70mm F4 but not the 24-105mm F4 which for me is a more interesting focal length range. For primes, they mention the Sigma 150mm F2.8 macro which I looked at in my Canon 20D DSLR days but never bought. There is an even more extreme 180mm F3.5 'L' macro lens from Canon. I fear these are too specialized to warrant their cost but with DSLR users switching to mirrorless they should become more widely available as second hand options. Just checking the internet, the 150mm macro seems to go for only 300-400 Cnd$. Maybe that would be a fun experiment some day in the future. Or perhaps by then Sony has come out with a native longer focal length macro lens".

 

First the 24 to 105mm has a Minimum focus of 38cm and goes to 1:3.2.

The 20-70mm has a minimum focus of 25cm and goes to 1:2.6, no question the better choice.

 

Sony already offers a 70-200mm F/4 macro that goes to 1:2. This is an excellent lens with very fast AF and can be used with additional C/U lenses and tele converters for more magnification.  

1 hour ago, Phil Rudin said:

First the 24 to 105mm has a Minimum focus of 38cm and goes to 1:3.2.

The 20-70mm has a minimum focus of 25cm and goes to 1:2.6, no question the better choice.

Phil,

did you ever test the 20-70 with a 140 FE dome?

 

Any good, or not practical at 20 wrt corner softness (and perhaps not enough room for the lens to extend at 70)?

19 minutes ago, dentrock said:

Phil,

did you ever test the 20-70 with a 140 FE dome?

 

Any good, or not practical at 20 wrt corner softness (and perhaps not enough room for the lens to extend at 70)?

I think the 180 dome is a better choice because of the 25cm minimum focus. I have gotten much better results with much wider rectilinear lenses that focus to 12cm with 140 port.