Chris Ross

As I recall the gamma curves from cameras flatten out in the highlights - it's certainly not linear response, I think that is what may be happening. In which case you could have a separate curve for the top end shot at a smaller aperture, lower ISO or an ND filter or some combination. Those high powers would probably manly be used where you can't get as close perhaps? Ideally you would use a flash meter.

Just to confirm as I read it, the HF-1 full and boost modes are listed in manual with limitations on usage with the thermal protection potentially cutting in too many flashes occur, the manual suggests 35-55 full power flashes before it cuts in. Retra doesn't suggest a number and advises to shoot in intervals and pause occasionally, they recommend 5 shots max on their boost mode. Seems like for practical purposes the maxi is effectively brighter than the HF-1 as full power without boost is as bright as the HF-1 at +2 and +2 seems like it has a limited number of flashes before throttling occurs. Regardless seems they are very close in guide number. It is interesting though that you measured the brightness at full, +1 and +2 as very similar. The manual notes that you should get over 1000 flashes at full and over 375 at +2 indicating the strobe is drawing more power in those modes. I also saw it has automatic throttling of light as thermal protection, so wondering if this has kicked in - though I see that the strobe is also meant to emit a long beep if it kicks in and I'm sure you would have heard it if it did. A further thought, both the maxi and HF-1 are very close in in output as measured by photoshop brightness and seemingly close to saturation and both at some power level step show a sudden drop from 90s to 60s in brightness. I'm wondering if the accuracy of using Photoshop to indicate brightness breaks down a little when approaching saturation?

I have tried this on land with a tent made from white ripstop nylon (for diffusion) It is surprisingly difficult to keep all of the air currents out, basically you have to completely weigh down all of the edges and closeup up the velcro zipper around the camera and/or lens to allow no air currents to get in and keep the subject still. Using a shield that is not sealed doesn't work period. You also have the issue that the shield will appear at least partly as the background if it is fully wrapped around. I think any air that gets in then has to exit somewhere, either that or billowing of the tent sides causes air to flow in and out through any opening. In water the forces are going to be greater so any sort of tent or shield will want to sway in the surge as well. Surge can move you, the diver around so anchoring any sort of shield is going to be difficult as the forces on it are quite high. If the shield/tent is loose fabric or mesh it will move and this movement will move the water on the other side of it. It might dampen it a bit but I don't think it will stop it. Being a wave, the surge will also diffract around the edge of the shield. Even if you could find something of an appropriate size, anchoring it on the reef without damaging things or causing subjects to flee I think would be a bigger issue.

Most operators in Lembeh support photographers quite well, the guides are very good at finding critters and will go off and find the next one while you are shooting . I stayed at Divers Lodge Lembeh recently, the boats all had rinse tanks, no camera room but did have a table in each room with good lighting to work on your camera. They were quite used to working with photograhers. Other locations have dedicated camera rooms and other features. In Raja Ampat, the Sorido Bay resort recently announced the establishment of a Seacam center on site to support photographers.

If I am reading things correctly Killiii's test shows some interesting points. First he tests at 8 FPS on the Apollo III in MTL at 12 = (max power) and it illuminates every frame and drops one stop in power by frame 8. It stabilises with constant brightness when power is reduced to 9 . The important thing to note that full power in MTL mode is about 1/2 the max output of the strobe. So it is one stop down from max power in regular manual mode. The Retra Maxi goes close to the this when set to -4 power- it starts brighter and drops to lower than the the output from the Apollo after a few frames. I'm wondering if the test would be more informative if you set the Retra Maxi at a power to achieve the same light level as the Apollo III at the 9 setting? It should give a few more frames at that setting compared to what was achieved in the test. The test then goes on to compare the Apollo III and Maxi at 6 FPS with a diffuser on the Apollo as it really needs one to get close on light quality. Settings are 12 and -6 respectively and the light output is the same by the light meter reading. To me it seems any comparison should be at a setting where light output is constant and equal. If you want high speed shooting then only getting the strobe output for the first frame or two kind of defeats the purpose. Whether one strobe is at half power and the other at 1/4 is somewhat irrelevant, to get a true comparison you want the same amount of light falling on your subject.

I think the degree of difficulty varies significantly depending on which manufacturer you are dealing with. The fundamental problem is attaching the Nauticam bayonet adapter to a flat port that you can use on your housing system, I believe that Marelux ports can accept the Nauticam bayonet adapter. You would need to work out if they offer a flat port of the right length. Isotta offer a flat port which will accept the Nauticam adapter and they include the 24-50mm in their port chart, it takes the H63 port. The Isotta ports will fit directly onto S&S housings without any adapter. I had a look at the S&S ports and looks like they might accept a Nauticam bayonet adapter, but the range of port extensions is quite limited. Nauticam port for the 24-50 is 16mm shorter than the Nikon Z 50mm macro while Isotta have a 20 mm difference in their ports. S&S specify the Macro port 15 with 20mm extension ring, so the Macro port 15 might work with the 24-50.

I would also add that in terms of field of view if you look at horizontal field of view - which to me dictates how large an object you can frame, then the WWL and WACP have a field of view of about a 13-14mm rectilinear lens. In a lens with barrel distortion the image is stretched more the further you are away from the centre so the diagonal field is that of a 10mm rectilnear, but you usually don't frame a scene from corner to corner. The horizontal field of a 16mm is about 96 deg, a 14mm is around 104 while a WWL wlll get about 106 deg. A fisheye will get around 144 deg, but may struggle with reach for sharks.

the fiddling is trying to work out which flat port will fit the 24-50. You could ask if anyone has made a zoom gear for the 24-50 on S&S, that would be the fiddly part if you can't borrow someone's design to get printed. Switching to Isotta might also be a possibility to use the WWL-C

This has been discussed in this thread: I'll lock this thread, please continue discussion in the linked thread:

It might be possible to change out the lug ring on the Nauticam port for the S&S lug ring and use it on the S&S housing. Not all Nauticam ports have a removable lug ring and then you have to work out if the port length is still correct on the S&S housing. There will likely be differing depths of the camera flange in the housing between different brands. The WWL-C can only be attached to the Nauticam bayonet adapter which requires the specific geometry of the Nauticam ports m67 thread with the two cut outs. I believe it can also be fitted to Isotta ports which use the S&S mount. Lastly you'll likely need to 3D print a zoom gear. All do-able but requires some data to sort it all out abd some fiddling,

Does the R50 housing have an arrangement like other Nauticam housings where you can pull the gear control out and twist and lock it in a retracted position?

To be fair, if you read the post Kiliii notes that he didn't have the strobes you mention available to test. Sure it would be nice to include them if available, but Kiliii is doing the testing and using his time to provide you with test data free of charge. You can only make judgements on the equipment you actually test so of course the comments apply to the strobes as tested. So you are saying there are two versions of the Apollo III 2.0? Or is the strobe tested the Apollo III and the new version Apollo III 2.0? It's not immediately obvious if not familiar with the product line.

Firstly thanks to Dave and Kiliii for the comprehensive reviews. On the question of salt, it seems to me it is very difficult to get rid of this salt in crevices etc. Just soaking won't do it, there's very little driving force to exchange fresh and salt water. On my previous Z240 strobes I would find salt crystals between in the space between the o-ring and the edge of the cap. Capillary forces hold the water in there and even after a 2hour soak or longer there's still salt there. If I change the batteries I can taste it, if I don't salt crystals eventually form. This is a problem on any small crevice, the gap between the two halves of the housing, buttons and control knobs, below caps like vacuum caps etc. At least with housing buttons you can press the button a few times to get salt water to leave, you can turn the knobs - but this doesn't do a lot I don't think. I have taken to blasting each control with with a blower bulb ( I use a Giotto rocket blower, surprisingly effective) , you can get a squirt of water out on all the housing buttons. I have Retra pure strobes, I aim the the nozzle at the base of each knob and the light button and blast till no more water comes out. I've just ordered a rechargeable air duster which I'll try out after next dive.

The larger domes have a larger radius virtual image located further from the dome which the rectilinear lenses cope with better as they focus further away with reduced magnification and more depth of field. The aim with a dome is to place the entrance pupil at the centre of curvature of the dome and this is fixed by dome geometry. Some domes are full hemispheres others are smaller segments of a sphere. A full 180° hemisphere has the centre of curvature level with the base of the dome glass and this is true regardless of dome diameter. Compact domes which are a smaller segment have the centre below the edge of the dome glass, which means it's back inside the extension ring. This present a problem for fisheye lenses as they will vignette when the entrance pupil and centre of curvature coincide. Do note that many domes labelled as fisheye or hemisphere domes are not quite 180° domes. The entrance pupil for most wide angle lenses is close to the front of the lens and this needs to be placed at the centre of curvature. There are two criteria, first to place the centre of curvature at the entrance pupil position, second check it does not vignette at this position. Compact domes are designed generally such that a 16mm lens light cone will coincide with the base of the dome when the entrance pupil is at the centre of curvature. Wider lenses need to be placed further forward so the entrance pupil is in front of the centre of curvature to avoid vignetting - which is not ideal. The Nauticam 180mm dome is an example of a compact dome designed for the light cone of a 16mm rectilinear lens. Fisheye lenses are fundamentally different to rectilinear lenses as the plane of sharpest focus is actually curve, not a flat plane. They work much better with dome ports for this reason. A 15mm fisheye lens produces an image that is 180° on the diagonal on full frame, a 15mm rectilinear, the diagonal field is only 110°. Fisheyes just work better in domes and will produce excellent images in small dome ports as long as they are full hemispheres that can accommodate the 180° diagonal field. In Nauticam for example the 140mm dome is a hemisphere, but the 230mm dome is a not a full hemisphere hence Nauticam recommends the 140mm dome as the best solution. they will also work with a 100mm (4") dome but the corners tend not to be as good. So smaller is not necessarily better for fisheyes, you just don't need the huge domes that many rectilinears need. Regarding your question about the 15mm lens yes it's quite wide but for rectilinear lenses a larger dome radius is better. The wider the lens the more important to get the positioning right as the corners are imaged from the far ends of the virtual images which is further from the ideal plane of focus and the more likely it will need a large dome to perform well. The thing to recognise is that all of this is important to get the best from your equipment, however there are diminishing returns. Fisheyes seem to be less sensitive to dome position, but are very prone to vignette. Many manufacturers make extension rings in 10mm increments of size, a few in 5mm increments. Getting it exactly right will of course be better, but there are limits to how close you can get to ideal based upon hardware limitations. It is easy to obsess about this an suffer paralysis by analysis. In Sea frogs the most likely issue with the Tokina is if the extension of the dome is too long it will vignette, the Tokina is a short lens making this more likely.

There's heaps of different options for inkjet printing, I assume when you say Hahnemuhle you mean photo rag? It's a nice paper though I don't think it's what I would pick for maximum print impact, probably more suited to certain landscapes. They have many options such as fine Art Baryta, Baryta FB and Fine art Baryta satin in that paper brand. The first two glossy and the other semi gloss. I print my UW images on Ilford gold fibre gloss, which I quite like. The choice will probably be dictated by what is offered by your local printing services, but if you are doing 30 images maybe they would be open to getting different papers in. I would also suggest getting a sample done first, especially if you don't soft proof your images.