Chris Ross

You can generally get two different strobes to work though they will need to have different settings if they differ greatly in power like the YS-D2 and HF-1. In TTL they will both have the same duration which means the HF-1 will be quite a bit brighter than the YS-D2 and you'll be trying to use compensation on them to balance the lighting. Generally it's simpler if the two flashes are the same, less to think about and murphy requires that the you'll have the high power strobe on the side of the camera where you want less light. On the choice of strobe the HF-1 is probably overkill for a m43 camera.

If you are shooting super macro having the flash on manual should work well without much need of adjustment. Your distance to the subject is more or less constant so the flash power will remain constant. I found on my camera with exposure mode manual using an olympus flash in the hotshoe that I could assign flash exposure compensation to a dial (OM-1 Mk1) with the flash turned on and it would allow me to vary it. BUT - it only actually worked to change flash exposure in TTL it had no impact if the flash was in manual, be it RC manual or regular manual. Presumably OM thinks if you are in manual you want fixed flash output By the way if you are using RC this sends out flash control signals prior to the main flash in manual mode if you are varying manual power from the camera, this is how it varies the flash power from the camera. I'm not sure what you are doing with TTL, it should only have a single pre-flash and be effectively instantaneous, though RC mode TTL might be a little slower perhaps?, I've never really used RC mode much. I also don't have your trigger and it may slow things up a little and behave differently to a regular flash. I assume you have already disabled red-eye reduction as it will cause significant delay. Looking through what I can see on my camera, you can do two things. First go to full manual and change flash exposure on the flash. Second use TTL and see if you can find out why it is slow - with an olympus flash in the hotshoe I can't detect any lag or detect a pre-flash. To use full manual set the flash power before you move in to your subject on a part of the reef at the high magnification you want to use. Then approach and frame up your subject. If you are the same distance then you should be very close on exposure as long as the flash is positioned such that it is not shaded by parts of the reef. If the subject is slightly over exposed stop down a touch more. I find I rarely adjust flash power if I'm shooting the same size subjects. On your settings - I tend to shoot f10-11 most of the time as it means I'm not fiddling with flash power too much and I generally want the depth of field. The only reason to try high speed sync to get beyond 1/250 is to get your background water darker. If you use HSS then you start to significantly lose flash power.

Anything specific you struggle with on the OM-1? It will have a little less depth of field in comparison with the m43 sensor in the OM-1 and you do need to place it well.

If you choose to upgrade to the OM-1, I would seriously look at options other than AOI. Your other option would be to search around and see if you can find an adapter to use your Olympus ports on a new system. Their housings are quite cheap but their dome ports are relatively expensive. For example their 4"glass dome is $899 while Isotta sell their 4.5"glass dome for $682.

The cable I suspect is not the weak point- rather it's where the coiled lanyard attaches through those two plastic mouldings. The plastic clip can also be an issue - I can say from experience they are quite difficult to unclip as the little cutout the wire clip seats in catches on your D-ring and needs two hands to unclip - at least one of which you want to be using to hold your rig. This can be a lot of fun when you are bobbing around trying to stay by the boat and unclip to pass up your rig. Combining one of these: lanyard with the lanyard most dive shops seem to sell to replace the coiled plastic would be much sturdier I think. Adding a quality bolt snap instead of the plastic clip would complete the ideal lanyard I think.

It's called a circular fisheye adapter for a reason, it produces a circular fisheye image, just like a Canon/Nikon 8-15mm at 8mm will on a full frame camera. It's should be about a full 180° field all around Zooming is perfectly fine I wouldn't expect any image degredation apart from the fact the lens aperture decreases a little as you zoom. When you zoom in until it just stops the vignette you should have something like the field of view of a 180° diagonal fishete like an 8-15mm at 15mm on full frame.

just a FYI, you can use your current N120 ports on an Isotta housing by changing the lug ring in most cases, it also has 3 M16 and one M24 port to use you current vacuum valve and other accessories in. You can purchase an adapter ring to use your Nauticam viewfinder. You may need to buy two ball adapters for their housing handles. The housing is slightly smaller, weighs 1kg less approx and close to $2K cheaper at backscatter. Seems like it might be worth checking out.

Yes I think best to talk to Balazs, he should be able to tell you how the system is supposed to behave. If you follow what I laid out above it will tell you the system is doing if you want to pursue it. Let us know what the end result is please.

The point of all this discussion is that changing shutter speed doesn't change white balance, the way it is does done for the water alone is to use a warm strobe and you can bring the WB to cooler temperature as a global adjustment. For the image overall you can make the water less green by adjusting the tint but the subject increases in magenta. It is important to understand how things are achieved so that you can take advantage of the phenomena to get your pics looking the way you want.

It seems the OM-1 housing uses the PEN ports, while the OM-5 uses the OM-D ports, which seems an odd choice. While the PEN port adapters are readily available, having an OM-D port housing opens up possibilities as it's a larger mount.

Second curtain sync is only to check if it is firing a pre and main flash. The pre flash fires at the start of the exposure and the main flash at the end in second curtain and if the exposure is long enough you can see two distinct flashes. If you can see two flashes that is a start. If it's only a single flash then TTL is probably not working. If you see two flashes connect up your strobe through a fibre optic cable and try taking a shot of an object with the flash very close, then again about a metre away, you should be able to tell if the flash for the more distant exposure is more powerful. You could also do this taking a test shot at f2.8 or similar and a second shot at f16. Then check if it gets the exposure right. What you see in the menu may vary depending on how the flash is emulated in your trigger it has to pretend to be a compatible flash to get the camera to fire the flash properly, hence the suggestion to test if it is pre flashing and then if the system can vary flash power.

There really is no threshold with camera sensors, if photons arrive they are recorded, you may not get enough to click the reading from 0 to 1 if you are that deep. But for exposing the water this is somewhat irrelevant - the red value being 0 or 1 or even 3 won't change the shade of blue a great deal at all. The main thing is the green/blue ratio, but even at 30m depth dark blue water might read R:G:B of 0:25:80 (from checking one of my shots) And that's plenty to get away from any threshold activation issue. Even if you were very deep and G:B was 0:50 for example, changing that to 1:50 wouldn't notably shift things it would still look very blue. You would also need to be underexposing at normal depths for this to be a possibility. Even though the readout in PS is restricted to 256 shades of each colour internally in 16 bit there is still a reading stored even if it's not enough to click from 0 to 1 in intensity. even with film it will still record, though that indeed has a threshold, but when it starts to record, the initial response is very flat plus we are talking about 1/250 sec exposures or thereabouts so reciprocity won't be an issue and there is some overlap between R:G:B channels as well. Camera sensors though are much closer to linear and in the shadows seeing a change in shade is more difficult. So the the fact that R:G:B photon ratios stay the same still stands.

From that screen it looks flash exposure compensation is enabled (not greyed out) which kind of implies that TTL is there. Have you tested to see if it fires a pre flash? If you set it to second curtain sync and the camera on manual with something like a 1 sec exposure, the pre-flash would fire when the shutter opens and the main flash would fire just before second curtain starts to close enabling you see both pre and main flash.

If you are looking at a new system, note that the AOI housings don't use a viewfinder they just have a window no optics to look into the viewfinder, they really are designed around using the rear screen. Assuming you go with new domes and ports for the 60mm macro and 8mm fisheye and are looking at a 4/4.5"dome port in glass prices including a 4/4.5"dome and macro port are as follows(backscatter) : AOI- OM-1 $2312 AOI - OM-5 $2212 Isotta OM-1 $3243 comes with handles Isotta OM-5 $2686 plus $218 for handles You need to add a full tray with handles for the AOI option. For the Isotta OM-1 it's ready to take ball mounts on the handles. At that price I'd seriously consider the Isotta, it's much more adaptable, you can get a 45°viewfinder for example and a greater range of accessories and if you can find one the Olympus mini flash is usable and a great triggering option. Of course if you decide to use your old domes the AOI is a bit cheaper, it's certainly usable, the PEN ports are smaller diameter though and will likely restrict which lens you can use, so the 12-40 f2.8 I think doesn't fit and adapting the excellent canon 8-15 fisheye (effectively combines the 8mm fisheye and a 7-14 zoom for reach) wouldn't be possible - but quite easy on Isotta.

This is not what happens. The colours you see are the result of sunlight shining through the water and reflecting off your subject and reaching your cameras sensor. The absorption results in the loss of longer wavelengths and is the result of distance travelled only. The popular analogy is a bucket. You have a constant stream of light entering your bucket and if you double the the amount of time the tap is on, you get twice as much water. Shutter speed and aperture are interchangeable in the bucket analogy, with aperture you use a bigger hose to get more light as you open up. To express this mathematically you use the term flux, this is the number of photons falling on a surface, in this case our sensor per square metre per second. The surface area of the sensor is fixed so to get the number of photons arriving you multiply flux by time to get photons/ sq metre. If you reduce the time the shutter is open you get less photons. Now this is the important part the colour of the light is already set by the distance it has travelled through the water and you have a constant number of photons of every colour arriving at every sq metre every second - the tap is right right at the sensor - the shutter curtain. The sensor records the colour of the light that arrives at its surface. Absorption doesn't change with time it changes with distance travelled and the camera records the light after it has travelled that distance through water at the time of exposure. There is no room for argument here, this is how light behaves. Now enough of the science behind it, I provided some examples above where I can't see the effect - If you want to argue further please provide some examples to prove your point.

That's a penalty of going to full frame, not having access to something like the Tokina at a reasonable cost. If Nikon did a high end APS-C option, it would make things easier for Nikon users I think, most people really don't need full frame. You can house the Z50 and Canon R7 but Nauticam and Ikelite are your only two options.

OK- it's for surface use then? if you have the lens you could try it out if someone has an adapter you could borrow. Longer lenses like that tend to be more of a problem for AF, but the bright f2.8 and presumably a sharp lens could help. I note that the list says: Other lenses not listed here typically work well, too.

Welcome onboard, nice Instagram gallery

Yes a suggested above, however with a 1.4x you are restricted to about 11-15mm zoom range of full frame, which is 15.5 - 21mm with the 1.4x. Below about 11mm you don't illuminate ethe whole sensor. I recall seeing reports the Nikon lens was not quite as sharp as the Canon equivalent, so I'm not sure ho well it performs with the 1.4x. Be aware that you need to use a Kenko 1.4x as it doesn't have the projecting front element and you would need to get advice on the right model to use on Nikon Z cameras. There is an adapter to use Canon EF lenses on Nikon Z, which you could consider - then the performance of the Canon 8-15 would translate across to your camera. It might be worth considering testing the adapter and 1.4x prior to committing to see that AF is usable. An advantage of the Canon 8-15 is that it has a zoom lock for locking out 10mm or lower focal lengths. With the 1.4x it would make it easier to set your min zoom.

No, Wolfgang is in fact correct, all colours are reduced proportionally when you use a faster shutter speed. Other effects like picture style might change things but the RAW files are the same colour shade just less bright in all channels for the shorter exposure. I dug through my files to find some examples I've shot, first is a basically a snapshot taken on a safety stop one at 1/80 and the next at 1/200. First the uncorrected file, only change is to reduce highlights to stop clipping and the auto WB equalised for both frames - it was a very small adjustment. Next the images are equalised in exposure . The images are in Adobe RGB to avoid having to try to recover the blues, they need to be viewed in a colour managed browser or other colour managed application. If the blues look flat, try downloading the file and opening in the browser directly of PS or LR. unprocessed 1/80 and 1/200 exposures Exposures equalised Next is a WWII Zero fighter quite close to shore and water is a bit greener overall. again side by side comparison with exposures at 1/160 and 1/100, unprocessed and exposures equalised. Unprocessed 1/160 and 1/100 shutter speed Exposures equalised To my eye the blues are very close in shade and I haven't changed the green noticeably by under exposing. The blues are of course not the finished product and I can clean up the bright water in the first set some. Equalising the exposures is done by using an exposure layer and is equivalent to changing exposure in camera. and takes away inclination for the eye to see shade differences that aren't real.

The Sony A6000 is APS-C and you would need a macro lens to go with it, either the 90mm which is big and expensive or the Zeiss 50mm which is a little slow on AF. It's a fairly old camera now, but would produce decent image quality close to the cameras you mention. As I recall the AF is quite a bit better on newer models of the A series cameras.

The Sony TC is 7mm longer than the Kenko 1.4x which 20mm thick, so this means the zoom gear needs to be 7mm longer. It's probably possible to adapt the design of the adapter ring used for the Canon 8-15 on m43 developed by Wolfgang and use it with the Nauticam zoom gear for the 8-15 plus 1.4x. If I recall correctly that one moved the zoom gear back by 5mm, so only needs a minor design adjustment. The Nauticam zoom gear for 8-15 plus 1.4x is 19538. Otherwise the other thread on the 2x plus 8-15 mentioned a zoom gear printed by our member Gudge.

No, don't have any Sigma lenses. Which SIgma lens do you want to use?

On my Galapagos trip some time back we were in the water snorkelling every day, sometimes twice daily with opportunities to interact with sea lions, turtles, schooling fish and also one snorkel we swam with Galapagos sharks and spotted eagle rays. Were using an Olympus tough cam, (pre TG series days) which worked fine. I certainly think it's worth it to be able to record what we saw and would have liked to have had a more capable camera. Fisheye might be a bit wide but having the long end of the Tokina would certainly be good.