Chris Ross

Welcome to the forums, good to see another Sydney-sider in the forums. Do you do any diving in Sydney?

You can visualise this by downloading the images and measuring brightness in photoshop at the square next to each circle. BTW Backscatter mention that the rings are at 30/60/90/120° - this must mean the angle is measured from one edge of each circle to the other edge. They are shooting with a WWL which has a 130° diagonal field which is what we see as the approximate diagonal measurement. As an example here is a polt comparing the Seacam 160D with a Retra pro max II without diffusers. The brightnesses are the pixel brightnesses sampled from Photoshop (100- K which is the black level which is what Photoshop reports): You can see the Retra brightness drops more rapidly than the seacam as you move further off axis.

The MFO-1 should be considered as a high quality low power diopter and also corrects for corner blurring due to the flat port. With a 90/100mm macro lens corner blurring is not really an issue. It helps on some macro lenses prevent hunting as the camera sees the subject as something at normal (non-macro) distances where the lens is more responsive in AF. IT help's on some lenses but if the lens/camera already focuses well it tends not to make a difference. A 45° viewfinder certainly helps a lot focusing on macro subjects on the sand but aiming is difficult till you get used it. For fast acquisition/aiming on quick subjects in open water, the rear screen of a 180° viewfinder may work better. The INON viewfinder is not as good in corners as the Nauticam particularly with modern mirrorless viewfinders which are quite "large"and require a large angle of view to see everything clearly, The corners are not great on my first version 45° Nauticam on an OM-1, the INON is reported to be not as good. It might work OK with the pokey little viewfinder on the A7CR-II - best if you can try it out on your chosen acmera before committing if possible.

I used an 8mm fisheye behind a Zen 100mm dome with my EM-1 MkII in the past it snapped to focus. You do have to watch fisheyes, the foreground can be much closer than it looks and can fall out of the depth of field if you are close. They have a lot of depth of field but it's not infinite at CFWA distances. DOF is less in the foreground so focusing in something fairly close can help.

I have everything stored in drawers inside cupboards. It really depends on how much space you have in your house. I used the Elfa modular storage slide out drawers to hold it all.

Perhaps, but the same can be said for any zoom lens and many people use them happily. IMO the entrance pupil location is most important at the widest setting, you are talking about using at 50mm or greater which would work behind a flat port. As far as I know all the port charts for zoom lenses are based upon positioning everything correctly at the widest setting.

You could try the 24-105 STM lens , it focuses very close about 0.2m, not sure if it's the same all through zoom range. It does get quite long so might hit the dome at the longest focal length. I seem to recall Adventurer likes it, he's posted about it on this forum.

For my flats ports it is the dimension from the inside of the port glass to the ports flange that sits against the housing. So my N85 flat port 45 is 45mm from flange to inside the glass.

The right tools will always help. But prevention is even better. Looking at you housing in the photos it seems to me there's deposits on there, in the video you posted and with the surface between the ports/adapters. I would suggest a good long soak after any diving session. Also recommend applying some grease to your screws holding on the lock mechanism. Should make them easier to remove. Does the mechanism rotate freely now? It should rotate quite easily- if it is stiff perhaps it needs service, there will an o-ring on the shaft of the control that unlocks the port and the shafted should be lubricated.

AI hallucination - it conflates things all the time. Yes definitely plankton, I get small straight very tight spirals floating around in photos on my local sites.

If I'm reading correctly it's N100 extension, adapter, N120 extension, port. Problem is with N100-N120 adapter. So can you remove port from port from 30mm N120 extension? This should be possible. If you can do this remove the port. Then use lens release button to remove lens then remove body, then remove combined N100 extension and N100-N120 adapter. You might be able to move the locking mechanism from inside then.

So the lens is too big to fit through the N100 port is what you are saying? Is it a port or extension on front? Assuming it must be a port which you can't take off to access the lens. If it's an extension of course you can remove the port from the extension then release the lens and extract body then take off the adapter/extension. I thought an extension went with the 8-15 setup? If the hex in the allen head is still sound, you could try some penetrating oil dripped from above and leave it to do its work for 24 hours and try again? It seems to me it should be the safety lock release as inside it just turns a cam to raise up a blocking piece that prevents rotation and removing that cover should allow you access to allow that tab to turn.

What lens were you using? I've used the Oly 12-40, Panasonic 8mm and even their 7-14 AN found it snapped to focus quite quickly. I now have an adapted Canon 8-15 - it's not always fast but that's to be expected with an adapted lens but a small shift on focus distance is almost instant most of the time on that - the flexibility is astounding though.

The 6000 lumen video light is specced to be 110 deg wide, compared to the strobe coverage 160 deg with wide angle diffuser , the coverage without diffuser is not stated, I would guess it's maybe 130 deg based on my strobe?? The pilot light beam is narrower and I think designed for the snoot aiming. The short version is that if you are setup with standard strobe positions to minimise backscatter the pilot lights won't be pointinng at your subject. My approach to a focus light and assuming mostly strobe illumination is a torch with a 60 deg beam and about 400-700 lumens in the cold shoe of the housing. It's relatively dim so less likely to cause the fish to leave but easily enough for AF to grab focus within 1m or so from and also being so dim it doesn't show up in the images.

Yes, you can certainly be a gear head and it's fun to toss around various options and you can be just as much a gear head with m43 as FF. Interestingly all the moderator crew now shoot or have bought into m43 with 3 x OM-1s and a GH5 in use. Having said all that Davide's post to me is a reminder not to succumb to paralysis through analysis and have constant FOMO about not getting the very latest and greatest. The sensors these days are so good there really is no bad choice and it comes down to other things like lenses that are available, battery life, native sync speed etc, things you can tick off, rather than subjectively staring at test images and noise plots and confusing your self. Make a decision and starting using your new tools!