Architeuthis

I think the problem is not the optical quality of the Sony 2x TC, but the optical quality of the lens that is used together with the TC. The resolution/performance of a lens without TC may be o.k., but an excellent 2x TC amplifies the weaknesses of a lens without mercy, if such weakness exists... See e.g. here these test photos of both the Sony 70-200mm lenses (GM f/2.8 II and G f/4 II). At 200mm/f4 both lenses perform nice, but at 400m/f8 when the Sony 2xTC is attached, the IQ of the G f/4 II lens becomes really low, while the GM f/2.8 II is still acceptable: https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1577&Camera=1538&Sample=0&FLI=5&API=4&LensComp=1662&CameraComp=1538&SampleComp=0&FLIComp=5&APIComp=2 It seems to me that the Canon 8-15mm is a high quality lens. IQ becomes a little soft together with the Sony 2x TC. Softness is, however, worse when I use the Canon 8-15mm together with the Kenko 1.4x TC (the non "HD" version). Also IQ of Canon 8-15mm/Sony 2xTC is comparable to WACP-C/28-60mm at the 60mm end (the 28mm end is sharper)... Wolfgang

Hi Martin, I have just bought the the Sony 1.4x TC for use with Canon 8-15mm in Nauticam housing and (mostly) 140mm dome (A7R5; have been using the Sony 2xTC&Canon 8-15mm now for two diving holidays (Croatia and Tansania) and it worked also nice (Image sharpness in center, more or less, comparable to WACP-C with Sony 28-60mm (both are, however, not "excellent"), corners similar. I do expect, however, better IQ with Sony 1.4x TC, therefore the acquisition of 1.4x)... The length of Sony 1.4x TC is 17mm, therefore an additional extension of 20mm should be perfect (in addition to the 30mm extension recommended by Nauticam; remember that Dreifish, based on the chessboard test, recommends 35mm instead of the "official" 30mm as theoretical optimum for the pure lens, w/o TC). The 3mm more, when the 20mm extension is used with the 1.4x TC, is fully in line with Dreifish's recommendation (alternatively one could use a 25mm (instead of 30mm)&20mm extension and this is probably also o.k.; I will be able to test the different extensions in the Red Sea only in March and can report afterwards (takeoff in 2_1/2 weeks 😋); I will also report my personal opinion, whether the switch to 1.4x TC indeed brings additional IQ and is worth (2xTC offers much better zoom range)... I have the Metabones V adapter and this works perfect with the Sony 1.4x TC and Canon 8-15mm. In case you have already the Sigma MC11 adapter you can test it out easily by yourself. In case you do not have an adapter yet, why not the Metabones V (at least theoretically, it should support AF modes a little better)? Wolfgang

I carry strobes with me in cabin lugagge, but Nauticam housing (in the travel bag) is checked-in in hardshell suitcase... Cabin lugagge, in my case, consists of Fotorucksack (approx. 10kg) plus Fotobag (approx. 4 kg). Just camera, lenses, flashes, Li+-batteries, dive computers, compass and travel documents. In addition, I wear a big "outdoor vest" with many pockets, just in case I would have to remove items from the Fotorucksack (never required, so far)...

The pulses, I guess, refer to electricity. The gas glowing in the flashtube will not stop emitting light inbetween pulses, maybe light intensity jitters a little at these extremely high frequency (remember the (rather slow) exponential decay of light intensity after a single pulse, shown sometimes here by our flash engineeres, who have the tools to record light intensity in time at high resolution))? In the end, a particle producing backscatter is illuminated by a flash pulse that lasts for 1/320s in HSS mode in your example. This compares to illumination by a flash pulse, lasting a little shorter than maximum shutter sync speed (depending on flash type and light strength selected), in normal flash mode. So the end result is expected to be pretty much the same...

I have just finished and printed an extension ring for the Nauticam zoomgear for the Canon 8-15mm fisheye lens with Sony 1.4xTC to be used via adapter (Metabones V in my case) on Sony cameras (A7R5)... After printing, I cut threads for three grub screws into the ring in order to fix it firmly to the Nauticam aluminium gear. Canon815_2xSony.stl

I find it difficult to find in the Internet a description how, exactly, HSS is working. Therefore my argumentation may have faults, but I can see none of them so far... According to what I was able to find out about HSS just now, the pulse frequency in HSS is mode is very high, up to 100 kHz, what makes the individual pulses merge and causing the flash to provide a single pulse, with, more or less, constant (but a little fluctuating) intensity that lasts for the duration of the entire exposure (=much longer than the shutter speed adjusted). => This would mean that in HSS mode the individual pixels are exposed to flashlight for exactly the time that is adjusted via the shutter speed. i.e. a single pulse ...

Who ever has come to this conclusions and what are the logical arguments behind it? Is there a single practical evidence on a real photo? HSS does not mean that a distinct region on the sensor is repeatedly exposed by the pulse of flashes, produced in HSS mode. Every single pulse of the strobe in HSS mode exposes a single, small region on the sensor and only once. The different regions of the sensor are exposed sequentially in order to achieve a shutter speed that is shorter than the "regular" flash syncronization speed, as the shutter is not able to syncronize the entire sensor region at once at a speed higher than sync speed (exceptionally fast sync speed is achieved via global shutter, as Sony A9III)... This means a single particle producing backscatter is exposed only once, is it in HSS or in "normal" mode. A photo produced in HSS mode should be identical to a photo produced by a single flash, when the flash is set to low power (providing short flash duration equivalent to a single HSS flash pulse)... => It is not visible to me how sequential flash exposure of different and consecutive regions of the sensor should give a different backscatter pattern, when compared to an exposure produced with a single flash... Wolfgang

Statistical comparison is NOT and NEVER can be relevant, when loss of human lifes are concerned - the safety standrards clearly should/must be better - no arguing and dot... Statistics is, however, relevant, when comparing the safety on liveaboards in different regions of the planet. I believe these standards are pretty the same and very low everywhere. Consider e.g. the terrible accident in California/US, few years ago, that costed the lives of approx. three dozends of divers (you can find a detailed discussion in Scubaboard). Somebody posted in Scubabordt a ground plan of the vessel: a common sleeping room for all (approx. 3 dozends) divers, double bunk beds in three etages, extremely obstructed. I believe such a boat would not have been approved, even in Egypt... => I just find it not fair when people are focusing now on Egypt, creating the illusion that liveabords are safer in other regions of the world... Wolfgang

Is there a solid statistical analysis available how the numbers (e.g. 16 boats lost in 5 years) compare to other regions of the world? I mean that one needs to normalize these numbers to the sheer number of diving vessels that cruise in the Red Sea - I guess the number of vessels cruising there is many hundreds - with the number of vessels that cruise in other regions (usually a few vessels per region - and also there boats are lost from time to time). Only then a comparison of the numbers of accidents makes sense... My personal observation is that the safety protocols in diving vessels are poor in Egypt, but I did not observe that these protocols are any better in other regions of the world (e.g. our Safari boat in Raja Ampat 2020 did not even have a second emergency exit from the lower deck in case of fire)... Wolfgang

It seems, after a period of deficiency, new UW strobes are sprouting like mushrooms: https://www.xadventurer.com/index.php?route=product/product&product_id=218 160 Ws, circular flashtube, 4800K, 7000 lumen video light (CRI90), Li battery pack, 150m depth rating

I fear the change of flight dates is a common issue these days... ☹️ Last November, on our way to Mafia Island/Tansania we had a similar issue with Turkish airline: The route was with Turkish airline from Vienna to Istanbul, Istanbul to Dar es Salaam and from Dar es Salaam to Mafia via domestic airline. I booked the first two flights as a package from Turkish and the domestic flight separately. Few days before departure, Turkish airline wrote me that the flight from Vienna to Istanbul was postponed for one day (but not the connection flight from Istanbul to Dar es Salaam, that was still one day before our arrival in Istanbul ...). I wrote Turkish airline bureau in Vienna whether they are crazy. The changed the scedule and we flew one day earlier (domestic airline and hotel were fortunately able to change the scedule accordingly)... => A lot of flurry, fortunately for nothing... => If possible, I book always via an agency as a package tour (would nor have been possible in this case), then the agency has to deal with these troubles... Wolfgang P.S.: When we were in Raja in 2020, we booked a package tour via agency (flight plus homestay plus safari) - no problems experienced....

Thank you for doing the measurement, Adventurer...👍 I do not understand what you mean with your last sentence: when a hemispherical dome as Nauticam 140mm is used and the entrance pupil is placed right at the center of curvature, there should be no vignetting - right? => When I use my Canon 8-15, Sony A7R5, Nauticam housing and 140mm Nauticam domeport with the 30mm extension recommended in the port chards, I cannot see any vignetting, neither with the 8mm circular fisheye image nor with the 15mm 180°diagonal image... In accordance no vignetting with Kenko 1.4x/2x or Sony 2x TC, when I correct for the length of the TCs by appropriate extensions... As a sidenote, there is a tread made by Dreifish, where he tested different extensions (in 5mm increments) UW. His outcome was that 35mm extension is optically even better than 30mm for the Canon 8-15, based on perspective UW/OW in split shots: I tested both 30mm and 35mm, but since I did not see a difference in IQ, I personally still prefer 30mm as the shorter extension is more convenient (with 35mm sometimes I could see part of the shade in the image, probably due to sensor IS and camera movement during photographing)... Wolfgang

Just in case you did not know so far, otherwise ignore: the Nauticam housings, as you buy them, usually have all the required electronics built in already. The only item required in addition is the mechanical valve plus the pump. When going for another vacuum system, one has to acquire another, complete, system. I would not bother to do so, I find this too roundabout (but I did not compare the prices, maybe one could save a few $$)... Wolfgang

Here is a long tread about the Canon 8-15mm with 1.4x and also 2x TCs: Bottomline is that high quality 1.4x TC is very good and even 2x TC is o.k. I have no first hands experience with the Nikon 8-15mm, but possibly the situation is similar...

uses Since you ask I can tell you that it is not my opinion, but a physical fact, that it is impossible to influence the spectral properties of ambient light by adjusting the shutter speed of a camera that is used to take a photo. By changing the shutter speed the amount of ambient light that is collected varies, but its spectral properties remain what they are... I believe that confusion in this discussion arose, because the effect of automatically occuring WB, color profiles and other processing tools are mixed with the effect that shutter speed has on spectral properties of the data collected on the sensor (=raw file). #1.: The crucial point is the discussion of the effect of shutter speed on the original raw data collected by the camera. Regarding the raw file, this file does not even contain any color information, just intensity is encoded, from black to white in different shades of grey (either 12 bit (=4096 different shades of grey), 14 bit (=16384) or even 16 bit (=65536 different shades)). The only color information that is contained in the raw file is the type of Bayer array of the sensor (https://en.wikipedia.org/wiki/Bayer_filter). Color information is introduced at a later stage, when the file is opened and the type of Bayer array is taken into account to process the raw data and produce a colorful picture. As Chris Ross rightfully states, shutter speed influences intensity values on all the different pixels on the sensor the same way, no "if and but" is possible at this stage ... #2.: The other point is how processing of these raw data leads to different colors (=adjusting WB). Usually people adjust temperature and tint of their UW photos in post via software, e.g. LR. To some extend, such processing is already done automatically by the camera/processing software (Auto WB/ color profile) and this is how the photo appears on the screen, as a first suggestion for further adjustments by the photographer. The way of automatic adjustments varies from camera model to model and, beyond that, can be finetuned in the camera menue - hence an almost infinite number of possibilities exists and the outcome can be different from model to model and from photographer to photographer. I would say this outcome is, more or less, unpredictable. Here comes ChisH into the play, when he says rightfully that in his hands camera X and flash Y give best results already as they work by themselves and little adjustment of colors is needed in postprocessing (under these conditions shutter speed may even influence temperature/tint of the "original" image on the screen, depending on camera model and also how the photographer tunes the automatic features of the camera in the menue)... => As the bottomline I would say everybody is right in his own way, but please nobody confuses spectral properties of water with, in practice unpredictable, automatic processing of raw data (spectral properties of raw data are constant and invariable by shutter speed)... Wolfgang

I switched from Kenko 2x HD to the Sony 2x TC and think the results are a tick better and also the required extension is shorter (Canon 8-15mm, Metabones V adapter, A7R5, Nauticam 140mm fisheye dome). I do not observe significant increase of CA, compared to the pure 8-15mm fisheye, when I use the 2x TC. I have posted full resolution UW photos here. Canon 8-15mm with and w/o 2x Sony TC and WACP-C/Sony 28-60mm are compared (real images, no test screens): https://www.dpreview.com/forums/thread/4779356 https://www.dpreview.com/forums/thread/4779452 https://www.dpreview.com/forums/thread/4779455 My personal judgement was that regarding sharpness/microcontrast in the center, the pure 8-15mm is better, while WACP-C/28-60 and 8-15mm/2xTC perform similar (maybe WACP-C a tick better @28mm, but a tick worse @60mm when compared to 8-15mm/2xTC). I think your test images show similar findings: the 2x TC softens the images to some extend... All combinations loose IQ towards the edges, I was unable to find a difference, worth mentioning, between combinations in this aspect (I consider the IQ in the edges as secondary, as long as IQ there is reasonably o.k.)... => Of course the FOVs of 8-15mm/2xTC and WACP/28-60mm are only overlapping and not the same, but when I read in reviews that IQ of WACP-C and FCP-1 are similar, I have no urge to buy FCP and test it out (for sure I can make photos with 8-15mm/2x TC at apertures much wider as f/13 (f/13 appears to be the limit for FCP))... => I personally have ordered now a Sony 1.4x TC and plan to use the 1.4x by default, just to be on the safe side when IQ is concerned... Wolfgang

Maybe of interest for Nikon Z camera owners: A new Sony E to Nikon Z adapter appeared: https://petapixel.com/2025/01/13/viltrox-af-adapter-brings-all-that-e-mount-glass-to-nikon-z-for-only-99/

I have put some images taken with Canon8-15mm/2x Sony TC into this tread, also with links to DPReview, for full resolution pixel peeping (see October 7th, 2024): => Although IQ with Sony 2x TC seems o.k. for me, I think it is, more or less, comparable to WACP-C/Sony 28-60mm, I am reluctant to use it and have ordered the Sony 1.4x TC now...

Is it known how AF is in comparison to the Metabones V and Sigma MC-11 adapters? I have A7R5 and use Canon 8-15mm with Metabones V, mostly for photo (there is no switch for photo/video on this adapter, but a confusing switch between "regular" and "advanced" mode (Metabones says C-AF&tracking should work with this lens also in video mode, when set to "advanced")) and can report about this combo: C-AF&tracking works well with the pure lens and also with Kenko 1.4x/2x TCs, as well as with Sony 2x TC (I do not have so far a Sony 1.4x TC; with 2x TCs AF sometimes hunts, I guess because the widest aperture is f/8). I have very little experience with video, but remember that I do occasional refocusing by the dumb during the recording and this also works well (cannot remember now whether this is with or w/o TC)... Regarding the second question, I cannot say about FF but was using the Canon 8-15mm on MFT (Oly EM1II and EM5II) both with Nauticam 140mm fisheye domeport and with Zen DP170mm (non-fisheye for rectilinear WA; to some extent similar to the Ikelite 8" "compact" domeport that Chris was linking): IQ in center and corner was pretty similar in practice, MAYBE even a small tick better with DP170. This indicates that positioning is not really critical with fisheye lenses and the larger radius more than compensates for the wrong positioning (the 140 domeport is, however, much more handsome UW)... => The situation, especially in the corners, may, however, well be different when using the larger FF sensor (but see the Ikelite description)... Wolfgang

=> Via shutterspeed the brightness/intensity of the bluewater is adjusted, but not the color/temperature/tint of the water.. When one adjusts the water color in post via WB, also the color/temperature/tint of the forgeround object changes and quite often becomes to cold, especially when a "cold" strobe was used to lit it. Then one has to use masks in LR and adjust the color of bluewater and foreground separately. Not only a lot of work, but often masking is not perfect and artifacts can be introduced in the photo... => Hence I prefer to use warm diffusers (e.g. 4500K) and then no or less adjustments are needed... Wolfgang

Since the monthly vs. annual payment price is more or less the same, I am not sure that there will be an increase of the monthly rate also here in Austria. As often, there is no official information by Adobe available up to now (except the info about prices in $$, but there the cheaper monthly rate is just adjusted to match the annual rate)...😟 => In order to be on the save side, I changed my Abo from monthly to annual payment...

When one compares test photos between the 28-60mm and the 24-50mm at comparable focal lengths and apertures, one can see that the 24-50mm performs pretty similar, the 28-60mm is maybe even a small bit sharper: https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1525&Camera=1175&Sample=0&FLI=0&API=0&LensComp=1687&CameraComp=1538&SampleComp=0&FLIComp=1&APIComp=2 => Since the wider f/2.8 aperture and 24mm are not needed UW (in connection with WWL/WACP), I am not tempted to buy and test the 25-50mm for UW use... Wolfgang

It seems that the Adobe standard photography subscription (LR&PS plus 20 GB cloud storage) will raise from 9,99$/month to 14,99$/month, starting from January 2025. The annual subscription stays constant at 119$/year, therefore one should change to annual subscription: https://www.dpreview.com/news/5008248286/adobe-photoshop-lightroom-monthly-plan-price-increase-december-2024 I live in Austria/Europe and since ever pay 11,99 Euro/month (annual subscription is almost the same with 143,14 Euro/year). When I look at the Adobe homepage, I still see the old pricing there... => Does someone know, whether the price increase is happening also outside US (=should one change to annual subscription also in EU)? Thanks, Wolfgang

It is the older model, made in China. There is written "Made in China" on the strobe...