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Adventurer

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Posts posted by Adventurer

    20 hours ago, John E said:

    Inon diffusers... From Driefish "The S-220 for example measure as 6650k without diffusers and 5400k with the Inon '4600k' filter."

     

    I am intrigued why the manufacturers may be off.


    Well, don‘t be too harsh with the manufacturers.
     

    First, we do know if @DreiFish Spectrometer has been regularly and properly calibrated. Second, has it been done in a completely dark room ( I mean pitch black room ) or outside or living room environment?

     

    The ambient light might heavily distort the spectrometers readings. 
     

    If you want to be precise you need to take it into an Ulbricht Sphere.

     

    However I highly appreciate Dreifish‘s home probing. Maybe he can let us more about his test environment? Furthermore I suggest to do multiple measurements for each unit to get an idea about measurement variance and errors.

    ·

    Edited by Adventurer

    On 5/13/2024 at 6:45 PM, Architeuthis said:

    (I, personally, am convinced that it is better to adjust the color temperature relation between artificial and ambient light already before the light hits the sensor (this was the reason for per-ordering two HF-1's plus filters). There will be always corrections in post-processing, also using masks, but the smaller such manipulations are, the better the final outcome will be (this is at least my hope))...😊


    If you want to go that way and be just super precise and optimized try the following: photo and strobe (white or grey) sand in your desired subject distance and use that white balance reference picture to set the manual wb. This will take the water effect on that particular dive,  strobe color temp and diffusers into account. 
     

    The manual Wb on most cams will include more parameters than just the Kelvin value. 
     

    I personally would not use the diffussors then unless I have to increase beam angle or want more soft light instead of hard light.

    • Like 1

    ·

    Edited by Adventurer

    40 minutes ago, Davide DB said:

     

    Please guys, just upload your video to Youtube and then link them in your post.

     

    Thanks


    sorry! I did’t know that rule.
     

    The video showed the left image of the bs promo pic screenshotted and taken in Adobe Lightroom. Then simply moving the white balance slider to the left until reaching approx 4500K.

     

    The result was the image presented on the right 😎 by bs to promote their diffusor.

    • Like 1

    ·

    Edited by Davide DB
    No video file attachment allowed

    On 6/2/2024 at 11:02 PM, Interceptor121 said:
    On 6/2/2024 at 10:15 PM, Adventurer said:


    It makes sense if Backscatter did not change the WB to 4500K in the first „no diffusor“ shot. 🤑

    Hahaha I had not seem that

    ok than this makes totally no sense



    „ Look mom, I can turn green water into blue! “

     

    ( now you do not need buy me that $39 diffusor )

     

    🤪😜

    13 hours ago, Interceptor121 said:

    Method watch the video get to the moment where there is the test shot and take a screengrab then convert to monochrome and sample the data

     

    Very smart. You still might have some deviation, depending if the lab conditions or camera changed over time.

     

    However,.. could you be so gentle and post the links of the video(s) you watched/sampled to do this and maybe 1-2 monochromed screengrabs to illustrate your method ?

    On 5/31/2024 at 6:57 AM, DreiFish said:

    I think that conclusion may be influenced by the fact that the Z240s weren't truly GN24 as advertised?

     

    Interesting impression. Maybe also factor in that to date you can just compare " aged " Z240s to the newer models. So the will always loose. Strobes are a degenerative product. They deliver substantial less light over time. 

    On 5/31/2024 at 6:57 AM, DreiFish said:

    Why do you say the S-220 is rated conservatively? Sea & Sea rates it as GN22, vs GN20 for the S-2000 and GN 16 for the Backscatter MF-2. This seems about right.

    Generally I would be very cautious with advertised guide number ratings on underwater strobes.

    If you ever compare them from website specs, try to stay within the same brand.

    Try not to compare S&S vs INON vs BS etc. by just advertised specs, this will just give you a rough indication.

     

    When I voiced up that the S-220 was rated too conservatively, I referred to D200, Z330, Z240 and S-2000 published guide numbers by INON. As I extensively shot all these products my subjective impression and some measurements with by own flash meter and lux meter ist that the S-220 leans more towards the Z330 and is for sure substantially stronger than S-2000 and D200. I would maybe describe it best as an miniaturerized Z240 with much better beam coverage.

     

    I have my Marelux Apollo III 2.0 incoming and the Backscatter HF-1 should also be with me next week.

    I still have to decide which of the three units will be my goto choice for the coming year. 

    The travel weight and size of two S-220 is unbeatable for the two new candidates.

    And yes, I am a nerd and I need to test these out for myself 🤣

    • Like 1

    ·

    Edited by Adventurer

    For all the Krauts in this thread:

    Quote

    Viele Wege führen nach Rom.

     

    ..and the rest:

    Quote

    Many ways lead to Rome.

     

    It was pointed out by some contributors to this thread that we only use strobes or video lights to restore colours underwater. I would like to remind that this is not the only way to do so and not the only purpose. Artificial light also brings back sharpness to the image in various ways. Artificial light also helps in restoring image detail on the shadows and better balances them with the highlights. Furthermore we have seen images in this thread that brought back colour by removing a certain part of the light spectrum. In fact that is what filters do, no matter if put on your artificial light source or the camera inside an underwater housing. Filters do not add photons, they subtract photons in a certain part of the light spectrum. 

     

    My personal opinion and experience is that CRI and ColorTemp of artificial light sources are highly over-rated product features which just apply to a very specific application. The original path to dial-in excellent blue background is with exposure. People praising warm strobes can be sorted into the "I shoot mainly on Auto-WB in tropical waters" group. 

     

    Mark my words:

     

    COLOR TEMP ON PRODUCTS IS OVER-RATED

     

    WHITE BALANCING IS UNDER-UTILIZED

     

    To optimize gear, shooters should pay more attention to the "real" lumen output on video lights (also if lumen output is constant or decreasing over burntime). With strobes look at the "burn time curve" (speed) or the integral under that curve to make a sophisticated buying decision. Like dome radi the latter info is unfortunately hard to get in our unprofessional industry. When you buy studio lights for professional photo shoots companies like broncolor or profoto serve you this info straight from their websites.

    ·

    Edited by Adventurer
    Added comment about levelling the housing.

    11 hours ago, Phil Rudin said:

    First it would be nice not to assume everyone is using Nauticam and simply acknowledge that extension starts at the housing and not at the port adapter

     

    A small reminder ( from the thread opening above ) :

    I am using Canon R6 Mark II in a Marelux housing in the above pictures. 

     

    Quote

    I think 121 is also wrong for Nauticam and may want to actually have the lens to test before posting recommendations.

     

    I have also worked myself through the Naughtycam portchart as a co-reference to try avoiding false-measurements and practical errors in application of the math. I conclude that in some cases I agree with 121 that the Naughtycam Portchart is also not free from false recommendations.

     

    Thanks Phil for your very informative answer and insights. I would like to add that this is a custom made BK7 glas dome for which I have the exact data. Therefore Marelux users: please do not derive any conclusions from my 30mm / 35mm extension. I was more interested in giving this simple do-it-yourself-setup to the public. The water tank and chessboard cost less than 20 EUR, I think. It is a cost effective way to practically verify your own math about the correct extension ring and gives you directions to go a few mm shorter or longer with the port extension. If you don't have a swimming pool and great weather like in Florida living @Phil Rudin at hand, it's worth a go, before hopping into the water. I encourage also Nauticam, Seacam, Isotta and SUBAL users to verify their dome positions. You might be surprised. As pointed out you have to be prudent about the 90deg optical axis chessboard alignment. In my first test (pictures above) the housing was also not perfectly levelled so occasionally you will produce a little bit of snells window. This will tell you to do better on the levelling.

    5 hours ago, TimG said:

    Gentlemen, whatever temperature strobes are being used, can we lower please the temperature of this discussion?


    Made my day 🤣 🤣 💙 💙 

     

    Very good remark - so many opinions here fighting for dominance. Time to rest my case.

     

    Just mentioning that backscatter released also cooling filters with their new hybrid strobe and have a nice demo on YT.

     

    • Like 1

    23 hours ago, Interceptor121 said:

    have read here again that 'using the edge of the strobes' avoids back scatter

    That is indeed not true.

    👏 policeman Massimo at work 🦾  It's noteworthy.

     

    23 hours ago, Interceptor121 said:

    Pointing the strobes outwards accomplishes no purpose whatsoever other than wasting power

     

     Good point and true. ✅

    However (as always) there are some exceptions to thumb rules.

     

    Here is a really odd one:

    You might have seen pictures with little or no backscatter when the photographer was shooting with the strobes completely outwards. Meaning he casted the light totally to his left and right and nothing on the wide angle subject. In very bad visibility this actually works. It will produce a light cloud left and right from your camera and can be very much compared when pointing your strobe indoors towards the wall or ceiling. The light will bounce and softly hit the subject.

     

    Unintended versions of these "light clouds" can be observed with optical slave triggered strobes using no cables in your dive group. Recently this has become rare, but when S-2000 wireless connection kit was new, you had a high chance to get a few "wasted" shots were the effect was observable.

    ·

    Edited by Adventurer

    F8

    Samyang 14mm positition with my computed 35mm extension looks pretty nice.

    The chess fields seem same size to me above and below water, what do you think?

     

    Unfortunately I have slight vignetting in the corners with that Dome and port-opening.

    I have to wait until next week, when I get my MARELUX 30mm Extension to see if it performs just as good. The vignette is also there outside of the water and it is purely an extension ring issue.

     

    In the second test picture the I feel the letters and chess board underwater look smaller.

    I am not sure this is my fault not being able to keep the chessboard exactly vertical or not.

    If it is not my fault, the picture exhibits the lens misalignment backwards which gives me hope for the 30mm ring.

     

    This shot is @ F8

    Samyang14mm_F8_35mmExtRing_looks_awesome_ADVENTURER.JPGHow I build a simple garden test ground to verify theoretical lens positions.

    Samyang14mm_check_test_setup.jpg

    Another test shot more far away @ F11 exhibiting smaller letters underwater:

    Samyang14mm_F11_35mmExtRing_looks_awesome_ADVENTURER.JPG

    Illustration on what should be observable.lens_alignment_figures.png

    • Like 3

    Looks like there is a timeout for editing the initial thread opener, so sadly I cannot move this to the top:

     

    Samyang Rokinon AF 14mm F2.8 F ( for Nikon F Mount )

     

    Samyang Rokinon AF 14mm F2.8 FE ( for Sony E Mount )

     

    If you are unable to get your hands on a used Canon RF Mount Version still operates AutoFocus, you can also buy the EF:

     

    Samyang Rokinon AF 14mm F2.8 EF ( for Canon EF Mount )

     

    All Versions of this lens seem to be on Optical Bench Hub.

     

    ·

    Edited by Adventurer
    Removed some obvious typos

    1 hour ago, ChrisH said:

    And the person arguing against a claim made by such a person is in my opinion up to prove them wrong by bringing better pictures to the table and explain how it can be achieved.


    You are misleading yourself and others with that idea. I claim myself guilty of having silenced discussions in the past by posting a spectacular image to make my point. 

     

    Be aware: Some very knowledgeable technically good photographers with good advice are miserable at composition, animal behavior anticipation or simply don’t dive enough all year round. We are talking about IQ (image quality) here and what’s technically possible, not art.

     

    To get you dialed into the topic, let’s Alex have a say about his picture: 

     

     

    This is very recent but there is more from him on YT were he talks about that particular picture and what technique he applied in other interesting YT videos.

     

    During the early 2000s many of the pros where using this strobe color plus calibration technique. Alex got the best shot ever, when he was going ALL-IN on this white-balance plus strobe thing. He simply had the balls to do it with a 105mm focal length while everybody else was using it with classic wide angle and fisheye lenses. Please note Christian, that there is vibrant golden color on the Bohar Snapper which makes this shot what it is.

    Hi Guys, I’d prefer to run this as a collection thread before we tear this apart with discussion and look at the general pros and cons of this focal length.

     

    Please pitch your 14mm lens options ( old and new ) including zoom lenses that include this focal length. As I am not at home (anymore) in the Nikon Z or the SONY E System, I will need your help.

     

    Especially older lenses via adapter might be worth mentioning, as this knowledge might be lost and hard to research on the net. We might find exceptions, where an old lens could be a jackpot candidate. 

    Posted

    I‘d like to compile with you a list of 14mm rectilinear lenses in this thread. The focal length that is so important for underwater photographers, because it has some one lens fits all arguments.

     

    I will edit this list, as the thread evolves.

     

    Some shooters claim that 130deg FOV is a magic sweet spot, others say 180deg FOV is a must. However these lenses very often require a full sphere fisheye dome OR an expensive heavy water contact optic to be sharp. If you look at the available dome port sizes of various manufacturers you will find that many are not full sphere. With these acceptable travel sized domes you have a good chance that 114deg FOV (found at 14mm) still can be positioned perfectly behind a dome without getting “tunnel vignetted”.

     

    This is all about full frame mirrorless lens choices for the demanding underwater photographer.
     

     

     

    Canon RF:

    - Canon EF 14mm II (via EF RF Adapter)

    the award winning Gaby Baratheu shot 🤩 was done with this lens

    MFD = 20cm / P-I-MFD= 100.56mm

     

    - Canon RF 14-35mm F4 L

     the goto lens for canon mirrorless 
    MFD = 20cm / P-I-MFD= 91.42mm

     

    - Samyang (Rokinon) 14mm F2.8 RF AF

    I happen to own this AF Version for Canon RF mount and have high expectations, as the entrance pupil does move less that a millimeter when focusing. This makes this lens rare and unique.

    MFD = 20cm / P-I-MFD= 116.34mm

     

    SONY:

    - Sony SEL14F18GM 14mm F1.8 GM

    has maximum aperture of F16 which can be a trap in very bright conditions if you do not ND filter it.

    - Samyang Rokinon AF 14mm F2.8 FE ( for Sony E Mount )

     

    - … 

     

    NIKON:

    - (old) Nikon 14mm F2.8

    - Nikon 14-30 F4 (Z-Mount) 

    - Nikon 14-24 F2.8 (Z- and F Mount version)

     

    SAMYANG

     

    Samyang Rokinon AF 14mm F2.8 F ( for Nikon F Mount )

    Samyang Rokinon AF 14mm F2.8 FE ( for Sony E Mount )

     

    If you are unable to get your hands on a used Canon RF Mount Version still operates AutoFocus, you can also buy the EF:

    Samyang Rokinon AF 14mm F2.8 EF ( for Canon EF Mount )

     

    All Versions of this lens seem to be on Optical Bench Hub.

     

     

     

    PS: This thread was inspired by Massimo, who thoughtfully mentioned… „I see a few misconceptions here a fisheye 15mm lens has less depth of field of a rectilinear 14mm lens the fact fisheye have field of view doesn’t mean they have more depth of field“

    IMG_6526.jpeg

    • Like 2

    7 minutes ago, ChrisH said:

    If you don‘t believe me, maybe you believe Alex Mustard 😉 

     
    I am aware of the fact that my good friend Alex Mustard has publicly voiced his subjective impression about warm strobes on many occasions, which I do not agree to.

     

    Be aware that Alex processes most of his images, as frequently shown on YT.

     

    His BBC Bohar Snapper shot is (almost) straight from camera, as the competition had very strict processing rules in the past. This is why this particular image lends itself so well into my argument. 

     

    Again. I encourage everyone to get their head around this one more time and work through this by first principles physics. It‘s the scientific approach.

     

    Scientific means not taking things for granted because someone with pristine reputation and excellent images has made a remark.

     

    Instead try falsifying / verifying them to yourself again. Stay hungry!

    8 hours ago, Interceptor121 said:

    I hate the new strobes with parabolic front. It does nothing for the angle of coverage it only helps the strobe deal with higher mechanical pressure


    WRONG

     

    I respect your personal opinion about not liking dome shaped strobes and lights. But please don‘t let your anger spread false information.


    Dome shaped fronts do not benefit structural integrity. The particular products you mentioned have the same depth rating and it was not the engineering intention to compensate anything with that.

     

    For the optical equation you know better, Massimo. You have written many great articles about dome port theory. When you reverse that and apply it to chasing the light rays from the inside to the outside water column through the dome, you will find that dome glas on lights will spread the light. Same applies to underwater strobes with domes.

     

    Eveybody can simply verify this by shining a domed dive light into water. Once dipped it you will notice a more wide light cone.

    1 hour ago, DreiFish said:

    The Inon 4600k diffuser on the S-220s is.. pretty ineffective. It reduced light output by about .2 stops, but also only took the strobe from 6100k to 5800k. 

     

    You definitely lose light output... more or less proportionally to what the strobes gained in the first place by having a cooler color temperature.

     

     

    Exactly! You just confirmed what I recommended earlier in this thread. Leave your CTO gels, diffusers and color conversion filters on the boat. It‘s a waste of energy, light and money.

     

    Start massaging your cameras WB instead to archive the effect.

     

    Especially INON S220, Z330 Type2  and D200 Type2 have such a great micro peened frontglas that you do not need diffusers.

     

    • Like 1

    5 hours ago, Chris Ross said:

    This is correct, if you white balance with a warmer strobe to make your subject neutral you cool the image overall which means the water is colder/bluer, no masks required.  This happens because the strobe illuminates the subject and not the water.  Though I would say there is no harm in 4600K light, I've used in clean tropical waters and results are fine.


    I expected this to arouse everybody and not receive flowers for my statement as just a minority of shooters has understood the physics behind this.

     

    Underwater photographers are less open to this idea and the correct physics approach.

     

    It‘s more accepted and understood in the underwater video community were some execute this by putting blue cooling filters on their video lights.

     

    I can just encourage everyone to burry the old recommendation that you need warm lights or strobes underwater.

     

    Once you embraced the idea that you have an absorption related depth of field for underwater color, you will improve your imaging and minimize travel weight.

     

    Actually you are the able to colorize subjects more distant then 1.5 meters from the camera. Alex Mustards „Bohar Snapper“ from the BBC Wildlife Photographer of the Year competition is a good example and also proof that you do not have to sacrifice cool blue water background when using this technique.

    On 5/28/2024 at 12:04 PM, Interceptor121 said:

    the fact fisheye have field of view doesn’t mean they have more depth of field


    Yes, this might be one of those strongly wrongly shared piece of advice which needs to be de-mythed and broken up.

     

    Has anyone a good DOF calculator for fisheye lenses at hand? Preferably one that’s free and online.

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