Chris Ross

Welcome Sabine, good to have you here, hope you enjoy the forums.

I waved it around the end of my cable while pressing the TV on button and it quickly fired both on the cable and the sensor itself (on retra strobes) A cable issue is quite possible and I would suggest assuming that is the problem till proven otherwise. The older TV remotes with the LED poking out are easiest to align of course , but a I used a SOny TV remote and it quickly fired by passing the window section over the acble end. In any case Pavel has provided some advice and I would certainly try that first.

This one is relatively easy, Google AI hallucinated and gave you the Nikon F (SLR/DSLR cameras) flange distance. I would think when measuring the flange distance you would want a piece of film in place as it has a finite thickness. Using google without the AI, there are multiple references to the dimension being 28mm and at least one where somebody measured and found 32mm.

A lot of people use them , they are cheap for a reason. Among other things the ports are setup for multiple lenses, but can only have the right positioning for one of them. They will let you get your camera underwater and seal properly and certainly you can take quite good shots with them. The vacuum system is not recommended as it can only be used to test, it's not water tight so you don't keep the case under vacuum while diving, which defeats part of the purpose of pre-loading the o-rings. There is a third party solution though. You could check with UW technics when the time comes if they support YS-110a. They are getting quite old now though.

What strobes do you currently own? The ikelite strobes have their won proprietary TTL system that only works with the ikelite TTL triggers which are now a little cylinder that connects to a housing bulkhead. They used to line inside the housings. I know at leats one person who has had ongoing issues with these triggers. But there is more than one way to solve the problem The new external UW technics triggers could be used on ikelite and assuming you have compatible strobes you should be able to use them . If not compatible you have a wide choice of other strobes you can use. I still think you should consider jumping to m43 generally a great system to use, with a lot more choices for housings and lenses, depending upon which body you choose. You could even use your 10-17 with the metabones speed booster.

Welcome aboard, good to have you here.

First thing to try is a new battery in your trigger. Double check the dial on the trigger is set to the right number. Definitely try it with manual position. Next see if you can trigger your strobes through the cables. Point a TV remote sensor into the cable and press any of the buttons. point the IR emitter into the fibre end. You might need to move it around. If this doesn't work point it into the sensor on the strobe. The IR remote should readily trigger most strobes.

Perhaps, but keep in mind Achtel is built around cinema where fisheyes are not favoured and the there is nary a mention of the Nikonos 13mm, though he does list the availability of some of highly specialized fisheye lenses, though it is not clear if they are water contact lenses. The issue as always is the lack of UW lens tests, air based tests can of course point you in the right direction, but not all lenses take well to being taken underwater for various reasons - one recently discovered parameter is a short minimum focus distance. I suspect there are others such as curvature of field which is readily taken care of on land by depth of field but if it bends in the wrong direction it might not play well with dome ports. I have not seen a convincing explanation of why some lenses are great on land but don't play well underwater - The Nikon 14-28 f2.8 lens is one I know of, there must be a reason for this and quite likely has something to do with not handling the curved virtual image very well. Another is they may be poorly optimized for performance at minimum focus distances.

Interesting ..... Achtel is located 5 minutes drive from where I grew up and less than an hour from home by car going by the address on the website. I don't that I would say forced to use conservative f-stops. You can only force yourself to make that choice. Me, I would rather stop down to where I need for depth of field or - say for a fisheye to get around the dome port issues than get the ultimate resolution - the overall image is most important and it's always a compromise. It seems to me that if you accept the statements from Achtel.com that domes reduce resolution to less than high definition partly due to the curved virtual image that you will be looking at fisheye lenses or water contact optics of some type for the highest resolution. Rectilinear lenses have a flat plane of focus parallel to the sensor while the virtual image is curved at some number of radii of the dome port in use. Fisheye lenses do not have a flat plane of focus, generally it is curved surface which may or may not be equivalent to a hollow sphere. Depending on the fisheye projection the focal plane may be circular or it may be flattened. But in any case it is much closer to the shape of the virtual image formed by the dome than the flat plane of best focus of a rectilinear lens. As an aside the S&S corrector lens attempts to do something like this - basically flattening the virtual image so that the host lens can digest it more readily I expect that the ability of water contact optics to operate at larger apertures is related to the fact that optic acts like a fisheye lens and it converts that image in to a flat focal plane that the rectilinear lens inside can digest. If all of this this is correct looking at land based tests of lenses probably only helps with center resolution it would seem??

Welcome to the forum Chris, good to have you here!

Yes that is indeed the difficulty. It seems to me that the suggestion of looking at Bali might e a good one if timing for the Maldives is not good, the advantage being that there is a huge range of options and flights to get there. this website seems to suggest Nusa Penida might indeed be a good option for the OP. https://www.zubludiving.com/articles/zublu-insights/manta-ray-seasons-in-indonesia

Unfortunately that's internet forums for you people run off on tangents on things that interest them. But seriously - please continue to dig and find resources and test images to make your points.

IMO, you are chasing a tiny improvement at best, there's thousands of great shots taken with the Canon 8-15 with the recommended dome dimensions. The test shots displayed on here of the banknotes certainly didn't set the world on fire. I would be interested to see some shots also - test shots are generally preferred as they are a shot of a flat surface and you don't have to work out if the softness is due to optics or if the foreground is falling out of the depth of field.

It depends on how small a subject you find and want to photograph, the MFO-1 reduces the frame covered from 36mm wide to 30mm wide providing 1.2x magnification. The SMC-3 gets 2.3x with the frame being 15.5mm across with 47mm working distance. The SMC3 focuses between 47 and 103mm and I expect it won't give you any overlap with the MFO-1 range. For me I would also factor in how often I find these things, if it's once on the entire dive trip maybe a better solution for this one critter is to crop?

While this is certainly an interesting exercise, there is a fundamental problem. You will see this notice on sites like optical limits: Please note that the MTF results are not directly comparable across the different systems! what does this mean - it means they are testing the combination of the lens, sensor, anti alias filter, de-mosaicing algorithm and any camera specific changes. But what does this actually mean? Well searching around I found a website that tested the same lenses on different camera systems. They tested a SONY 50mm f1.2 on both a Sony and Nikon camera and on SONY (A7RIII) its peak Imatest score was 3611 at f2.8 while on Nikon (z7) it was 4128 @ f2. There is also a test of a 35mm f1.4 EF lens on SONY, Canon and Nikon. The Canon camera used has an anti alias filter so returns significantly lower scores on the same lens Here is the site: https://photographylife.com/our-canon-and-sony-lens-reviews-will-have-imatest-data-comparable-to-nikon So where does this leave us? We can certainly work out the fastest knife in the drawer in any particular brand of lens if they are tested on the same camera. We know that a 3600 score will pretty much certainly sharper than say a 2500 score, but unless the top contenders are tested on the same system we will struggle to decide which is first place. We could use the plots supplied in the link above to approximately convert between the systems, however they only really apply to the cameras they use for testing. As for the Nikonos test the biggest problem I expect is the fact that the testing was done on a completely different system. The centre score in LP/mm should still be valid for a full frame sensor with the same characteristics - the corners of course are a different story. And to be truly comparable the Nikonos is tested UW, you would need to test the other lenses UW as well to compare them. Then there is the problem of different amounts of water between the lens and target. You could probaly validly compare the 8-15 with a Nikonos 13mm equivalent but perhaps not a 16-35 lens for example.