Another relatively recent development in optical equipment for underwater photographers is the availability of a seeming plethora of “wet” close-up lenses. In this episode of Wetpixel Live, Wetpixel Editor Adam Hanlon and regular contributor Alex Mustard chat through the options and make some recommendations about which macro underwater photographers should consider.

Nice information there, - what is the brand of the +3 in water diopter - I heard "flip" as the name of it but searching I can't find it - is it still available?

I've found that macro lens data seem to be a bit of a state secret, none of the UW sites provide much information to give you an idea of how much magnification you might get and the resulting working distance.  It should not be that hard to produce the equivalent of a port chart giving max magnification on the popular macro lens focal lengths and associated working distance.

Sounds like a project for 121.

For the CMC-1 this data is published, but I think it’s the only one. Makes it very hard to compare. 

Sounds like a project for 121.

I have two questions about the video:

I use MFT with the Zuiko 60mm and CMC-1 on a flip diopter and find it very useful. The CMC-1 is already very strong and sometimes one ould wish a less strong diopter, just to increase magnification a little.

What would be the diopter that is equivalent to the 3+ diopter of the video on a MFT sensor?

Or could it be that the magnification range of the 105mm FF lens plus the 3+ diopter is already covered by the Zuiko 60mm alone?

Wolfgang

Just now, Architeuthis said:

I have two questions about the video:

I use MFT with the Zuiko 60mm and CMC-1 on a flip diopter and find it very useful. The CMC-1 is already very strong and sometimes one ould wish a less strong diopter, just to increase magnification a little.

 

What would be the diopter that is equivalent to the 3+ diopter of the video on a MFT sensor?

Or could it be that the magnification range of the 105mm FF lens plus the 3+ diopter is already covered by the Zuiko 60mm alone?

 

Wolfgang

You don't need a +3 diopter on MFT as almost all lenses focus at less than 1 foot from the front.

This was needed with full frame optics that had 30 cm from the lens in water this becomes 40 cm 

Neither of 45 60 30 mm for MFT need any diopter other than the CMC-1 and actually the 30mm focus already closer than the CMC-1 would allow

The +3 wet lens is actually a +5 that was made by FIT.

I understand that they are no longer making them sadly.

In terms of compatibility with M4/3s, it will be as compatible as any other wet lens, but will only be needed if your lens has  a working distance that is some distance in front of the port and/or this is a problem. I wood suggest that if you are finding the CMC a bit strong, and can still work the lighting, just back off a little?

Adam

1 hour ago, adamhanlon said:

The +3 wet lens is actually a +5 that was made by FIT.

I understand that they are no longer making them sadly.

In terms of compatibility with M4/3s, it will be as compatible as any other wet lens, but will only be needed if your lens has  a working distance that is some distance in front of the port and/or this is a problem. I wood suggest that if you are finding the CMC a bit strong, and can still work the lighting, just back off a little?

Adam

 

As Adam says. The 60mm on MFT body focusses at 12 cm from the port. Until then there is no need for CMC-1

If you step away further closer you need to remove the lens as infinity focus is at 7 cm with the CMC-1 

So in short unless you have something smaller than 17.3mm wide there is no need for any wet lens and that is a really small super macro 2x wide frame

This is a great discussion, thanks to all, a lot of information  (I am still thinking about and working on it)... 

I had a look in the interent, regarding magnification (regardless of working distance): final maximum image magnification of Zuiko 60mm on MFT and Nikkor 105mm on FF is 1x for both at minimum working distance in air. Since the diffraction index of water is 1.33, together with the planport the magnification should be 1.33x...

I created this table, based on info provided by Nauticam:

SMC-1 and CMC-1 yield quite strong magnification and similar results on both MFT and FF. The problem with SMC-1/CMC-1 is that there is not only a minimum working distance, but also a maximum working distance exists (the usable range becomes smaller with increasing magnification) - hence backing up to reduce the magnification is possible for a small range only. There is a gap in usable working distance inbetween the bare lens and the lens/diopter combinations (SMC-1/CMC-1).

The 3+ lens solves the problem for FX. It seems that CMC-2 is designed as the equivalent diopter for MFT system.

Also the SMC-1 might serve this purpose on Zuiko 60mm/MFT, but I could not find info for magnifications with MFT lenses...

Wolfgang

This is a great discussion, thanks to all, a lot of information  (I am still thinking about and working on it)... 
I had a look in the interent, regarding magnification (regardless of working distance): final maximum image magnification of Zuiko 60mm on MFT and Nikkor 105mm on FF is 1x for both at minimum working distance in air. Since the diffraction index of water is 1.33, together with the planport the magnification should be 1.33x...
I created this table, based on info provided by Nauticam:

SMC-1 and CMC-1 yield quite strong magnification and similar results on both MFT and FF. The problem with SMC-1/CMC-1 is that there is not only a minimum working distance, but also a maximum working distance exists (the usable range becomes smaller with increasing magnification) - hence backing up to reduce the magnification is possible for a small range only. There is a gap in usable working distance inbetween the bare lens and the lens/diopter combinations (SMC-1/CMC-1).
The 3+ lens solves the problem for FX. It seems that CMC-2 is designed as the equivalent diopter for MFT system.
Also the SMC-1 might serve this purpose on Zuiko 60mm/MFT, but I could not find info for magnifications with MFT lenses...
 
Wolfgang

Also water magnifies but this also means your working distance also increases so the net effect is zero you achieve 1:1 being further away but not more


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11 hours ago, Interceptor121 said:

Also water magnifies but this also means your working distance also increases so the net effect is zero you achieve 1:1 being further away but not more


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This sounds reasonable, by intuition.  Can you please give a reference for this effect (constant magnification factor OW/UW because minimum focus distance changes accordingly)?

I will then edit/change the table accordingly...

Wolfgang

Wolfgang the table remains
Incorrect as the CMC-2 achieves nothing with 60mm
Not sure about the effect water provides magnification but the lens itself can’t exceed its own magnification regardless because it can no longer focus
So in effect you are further away buy get more magnification net effect zero
I am neglecting distortion because past 35mm is not an issue


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12 hours ago, Interceptor121 said:

No magnification as indicated by nauticam are for a specific lens don’t apply to all lenses equally
CMC-2 with olympus 60mm achieves nothing that the lens can’t do on its own. Those close up lenses have a maximum working distance that works with your lens set at infinity and a minimum working distance that works when your lens is set to the closest
When the wet lens maximum working distance is further away than your camera lens minimum working distance the benefit drops to few cm useful range and this means the lens is not really worth using.
I have tested all the lenses in question and the only one that gives a benefit to the 60mm is the CMC-1 the others have such a minor effect they end up being an hindrance as the increased magnification is none and the ability to focus further away no longer there
In essence with the 60mm you dive with the CMC-2 on the flip diopter off the lens and when you find something really tiny that the camera can’t get close enough to fill the frame use the CMC-1
The olympus camera unfortunately doesn’t have a manual focus guide to tell you when you are at the minimum distance so you need to use other tricks to figure out when you need to use the wet lens


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Thanks for this real live input on CMC-2 with Zuiko 60mm (I was close to ordering one and spending money for nothing...). It shows, again and again, that one only knows whether the performance of a new item is as expected, after buying and testing out in real life...

Another thing is that the OPTICAL magnification factors achieved by lens+/-diopters are not yet the entire story, but represent more a milestone, required to avoid total confusion. At same magnification factors (e.g. 1x) the magnification will only be correct, regardless of different sensor formats (FF and MFT (and, of course, APS-C)), when printed out at the size of the sensor (17.3*13mm for MFT; 36*24mm for FF). The size of the images itself will be different, the bigger sensor covering a larger area, but magnification of the object will be identical. Since the images are always scaled up and finally projected/printed at a certain physical size, the final magnification factors are different when th eimages are viewes at the same final size: At 1x magnification a 17mm object will fill out the entire MFT photograph, while it will fill out only half of the FF image...

Here is a second table, that shows the final magnification of an object, when the images are printed out/projected at identical physical sizes (MFT scaled up relative to FF):

It shows, just in numbers, what you were saying: Zuiko 60mm ALONE (and without any gaps in possible focusable distances) easily covers the macro range up to the maximim achievable with the Nikkor 105+SMC-1 on FX. Accordingly, Zuiko 60mm+CMC-1 covers a similar macro range as Nikkor 105mm+SMC-2...

Hence an UW-photographer on FF needs a macro lens that provides already by itself 2x magnification in air, in order to have the same flexibility as another one with a MFT camera has. With lenses with 1x magnification the many diopters are required...

Numbers are according to the data provided by nauticam and may, as Massimo says, not be correct...

Wolfgang

Nauticam data is correct for the specific lens tested however it cannot be generalized
When detailed test data is provided for example CMC-1 is accurate as well
But you can’t say a given lens will always have 2x or whatever factor magnification nor guarantee a minimum magnification


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2 hours ago, Interceptor121 said:

Nauticam data is correct for the specific lens tested however it cannot be generalized
When detailed test data is provided for example CMC-1 is accurate as well
But you can’t say a given lens will always have 2x or whatever factor magnification nor guarantee a minimum magnification


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The CMC-2 factor was calculated by the ratio of the average factors given for both CMC-1 and CMC-2 (4.5x vs. 2.8x) on compacts. The only numbers I was able to find (of course not the same situation, I do not know what the average focal length of macro in compact would be). No info for magnifiction with Zuiko 60mm and whether it is useable or not (I just asked at Nauticam, let's see what they say)...

Wolfgang

19 minutes ago, Architeuthis said:

The CMC-2 factor was calculated by the ratio of the average factors given for both CMC-1 and CMC-2 (4.5x vs. 2.8x) on compacts. The only numbers I was able to find (of course not the same situation, I do not know what the average focal length of macro in compact would be). No info for magnifiction with Zuiko 60mm and whether it is useable or not (I just asked at Nauticam, let's see what they say)...

Wolfgang

Number on a RX100 compact I would say is not meaningful for comparison. I have tried the CMC-2 for wetpixel. It makes sense with the 14-42 zoom for video but is useless and actually annoying with the 60mm as you can't step back

Panasonic camera have a feature Olympus doesn;t have you can see when you are at minimum distance for Olympus you need to use the Pre-MF function otherwise you don't know where you are and if you need to use the wet lens or not

This was a really excellent discussion, especially about how most people try to start with too strong of a lens. 

I am setting up my new kit of an a6100 in a seafrogs housing. Plan is to use a tokina 10-17 on a sigma mc-11 in the 6in dome for WA.

I would also use the 16-50 kit lens in the stock port for general use, and add a diopter to it. I am thinking the UCL165M67 as my choice, but wanted to get some feedback from the experts here on that plan.

This was a really excellent discussion, especially about how most people try to start with too strong of a lens. 
I am setting up my new kit of an a6100 in a seafrogs housing. Plan is to use a tokina 10-17 on a sigma mc-11 in the 6in dome for WA.
I would also use the 16-50 kit lens in the stock port for general use, and add a diopter to it. I am thinking the UCL165M67 as my choice, but wanted to get some feedback from the experts here on that plan.