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Interceptor121

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Everything posted by Interceptor121

  1. That's right however we do not know how any of those compares to the sea and sea unit of the op The time constant of the circuit is more or less t=RC obviously if the circuit is similar and so is the battery pack larger capacitance means more time even if the speed is the same If one strobe is 150 W and the other is 100 W and the recycle time ratio is 2.5/1.5=1.66 this would indicate the larger strobe charges at slightly lower speed actually
  2. I recently tried this using the timelapse function of my camera The strobes when fired at full power with a set of eneloop pro that are a few years old take 2.2 second to give ready signal once they are fully discharged. I do not have a new set of batteries so I cannot tell you if that would improve or not today According to the manual after 20 consecutive shots at full power the strobe will go in protection mode, this has never happened to me yet mostly because I rarely fire the strobes at full power Having been to Galapagos from memory I don't think you will need to shoot the strobes at full power either unless you are shooting at f/16 I have an MFT camera so my smallest aperture for CFWA is f/10 and rarely have an issue with strobe power When I look at the specs of the Retra they indicate 1.5 seconds for the Prime X and 2.5 for the Prime to 80% of power I do not have those strobes so I cannot tell you if those numbers are true or not but if they were true you would really only have a benefit with the Prime X
  3. I was recently running a boat and one of my guests had a set of Inon Z330. He told me he had issues controlling the power of the strobes and even at low setting in close up work they were still too strong. This reminded me of an experiment I did a few years back and never decided to publish, perhaps the time has come. In essence I believe there is no value in having curved shaped video lights or strobes for two reasons 1. The light source is essentially on the glass is not a far distance light ray that is going through water 2. There is an obvious effect of scattering around the light itself that actually expands the beam. This is very noticeable with strobes where you literally see a cloud around the strobes that is is due to light particles colliding with water My conclusion was at the time that light at the strobes actually expands compared to use in air due to rayleigh scattering for what concerns blue light while red tones are absorbed by water and therefore a dome shaped strobe or light front is not necessary. Also important to make a distinction between angle of coverage and diffusion of light So my take is that curved surfaces increase diffusion but don't really do much to increase actual coverage angle, at short distance the diffusion effect may be too strong and the light source be too invasive and need a device to reduce the beam I did not want to publish the video evidence at the time (you can do yourself in a sink) because those products had just been released and did not want to create a ****storm however I personally have no interest in curved shaped lights they are not practical and make things more complicated than required and I will stick with flat lights for the foreseeable future...
  4. In my experience in the Red Sea shooting a cyan 60 with a red filter of your choice covers all situations with two lights. For photos I tend to use a cyan 90 as strobes are much more powerful or another blend that I do not recall what is called I do not like the CTB or the URPRO too much they have orange cast and the blue are never deep enough Generally for photos I use magic and for video keldan filters This time I have also used no filter on the lens and cyan 60 on the light or nothing on the light in some cases it resulted in too warm image that I corrected later
  5. At 10 meters any camera works White balance works like this Sum of RGB = 1 Initial coefficient a b c scene is aR + bR + cB = 1 if R is very small and the white balance operation changes a to a large number to compensate you get still a small number and the result is increased noise on the red channel Camera manufacturer change the maximum amount of color correction that is possible hence the 10000 k or 15000 k limit although the camera may balance with higher 15000K the effectiveness of it may be reduced as noise can be very high The rest which is really important is the photo style which is normally gamma compressed or log compressed together with bit depth and bit rate. If the photo style color science is not well implemented and the files are small they are harder to correct so having a better white balance in camera becomes more important
  6. The 180 viewfinder is less useful than the 45 because it can be replace by the LCD and also looking directly into the one built in the housing The 45 is useful for shooting at awkward angle but takes time to get used to. If you want to buy one because you can't deal with the LCD as is this is the one to go for
  7. A 4k 15.6 monitor is just pointless your eyes can’t resolve that level of resolution A 27” 4K monitor at a regular working distance is far better than a 2K monitor to evaluate sharpness The issue is visual acuity vs screen size and resolution To say that a certain ppi is right or wrong is not the right approach as it doesn’t consider viewing distance and screen size 32” 4K monitor is better than a lower resolution monitor of you look at it at two feet I have no issues with my 27” benq monitor and I can see things I don’t notice on my laptop not because the ppi is lower but because the laptop screen is too small Sent from my iPhone using Tapatalk
  8. Diffraction is a function of crop factor and wavelength of light and aperture A resolution chart showing that a lens is not performing best at given f number doesn’t solely indicate anything For reference the f number for full frame is normally around f/20 however if depth of focus matters the loss doesn’t matter In this image f/22 works better Sent from my iPhone using Tapatalk
  9. The sensor conversion of photons into electrons follows a linear model Which means each pixel is read and stored for what it is and the values of R G1 G2 and B are set At this point a white balance read applies a coefficient to each of those to bring it to a ‘correct’ value however if there is no red left at all in the scene the red channel will stay low and brining it up will only add noise On the other hand you can decrease the value of blue and green channel but ultimately they will stay high This is why when you white balance at depth there is a washed out look you may as well desaturate the blue and green channels yourself The most critical part is to avoid clipping of the blue channel as other wise you may also have banding or other nasty effects I looked into this few years ago and had a very detailed discussion with daniel keller at keldan Filters reduce the amount of light true but mostly avoid the blue channel to get too high and therefore make white balance more effective A 2 stop filter reduces light 75% and 4 stop filter 93.75% but works mostly on the blue and red channel putting things in check and allowing a camera to do a better job at white balance My approach is to use a filter until I see that I am needing to go too high with ISO. Generally I avoid using the camera without filters unless am doing macro and using 100% lights or am at the surface Sent from my iPhone using Tapatalk
  10. White balance is a multiplication it simply takes the reading of RGB and applies a multiplier The issue is that when a value is zero even multiplied it is still zero When it comes to blue which are prone to clipping you decrease saturation yourself and then you get the effect you want if that is what you want I don't know how those people make those tests but if you test one in log or raw the others have to be tested the same In VLOG you do get that desaturated look that you talk about again those 'tests' do not explain anything of what they do and as such they are not test they are just opinions The issue is of course the fact that conditions can't be reproduced unless you dive with the two cameras. What does 15 feet colors mean one day is not another Those short articles are really underwhelming they may as well not post anything
  11. White balance under 50 feet? Is that a joke? There is no red color left at those depths the camera may produce something but with an RGGB bayer sensor is likely to be off whatever the case Some canon cameras white balance deeper that doesn’t make the colours any good Am really not sure about the understanding of sensor construction some of those people have Nevertheless the housing of the GH6 costs more than sony full frame Not sure is nauticam is secretly supporting sony but today their only housing that are competitive are sony and Olympus the rest is way over what anyone would want to spend I see how second hand market is the way to go assuming you find anything you like Sent from my iPhone using Tapatalk
  12. I think this camera is far more interesting than some full frame on the market due to lower price, less rolling shutter and great latitude https://www.cined.com/fujifilm-x-h2s-lab-test-rolling-shutter-dynamic-range-and-exposure-latitude/
  13. They would if you could However if the fish moves and your composition didn’t have the perfect settings you can’t Or you jumped with a too short or too long lens Ultimately only landscape photography can have the perfect setting dialled in and then it conditions are perfect match the shots Underwater many things like bracketing don’t work with strobes so you have less opportunities Sent from my iPhone using Tapatalk
  14. That was an example In terms of skill issues looking at a few trips I have dome quite a few photographers had a level of fitness inadequate to take certain shots I had several occasions when someone said please take me where you go I had some counter current swimming and they were gone Partially also because of diving equipment choices i.e. split fins may be comfortable but unsuited to the task Generally I have the best equipment for what I decide to shoot and know how to take that shot however I have plenty of technically good shots that mean little to me but in some case less technically perfect that are more powerful but didn’t have the time to set things best or I had not made the best choice to go underwater with Sent from my iPhone using Tapatalk
  15. cost, weight, ergonomics usually are a trade-off against quality The WACP is extremely heavy I was on a boat once with a small build american lady she could not actually carry the rig herself outside the water and getting out of the water was a problem In addition with the drag and the current she was flying everywhere and actually not able to take the shots others could So here is a good reason to go for a smaller set up just there
  16. There is no doubt that having the right tool and exposing an image properly is important However the process of 'judging' an image to find flaws does not match the large majority of people out there that look more than anything else for impact of an image This is not unique to underwater photography is the same with land photography I know which images a judge will like and what images I like and they are seldom the same thing Besides many photographers (land) that are competition winners say exactly the same thing One example is corner sharpness, ok it is better if the corners are sharp however the subject is not in the corners Analogy to nightscapes you shoot a milky way with a lens that has coma in the edges, however nobody cares about what is in the edges
  17. I replied on your other thread The internal battery appears to do a really poor job Now Nauticam should consider a complete redesign of their GH6 housing to have the battery pack as I said since day 1 and then we have options as frankly not everyone needs a full frame camera and almost nobody needs 8K
  18. Canon battery specifications appear over optimistic Battery 2130 mah 15.3 wh Consumption in 4k50 12.9 W Recording time 40 minutes Energy used 8.6 wh Battery efficiency 56% which is terrible Battery pack 72 wh typical efficiency 70% 50 wh /12.9 = 3.9 hours Total 274 minutes Not sure if the battery gets hot in the process but 56% is very very low so external power with that camera is a must Sent from my iPhone using Tapatalk
  19. It is a bit more complicated than this Unless you play your file locally you will need to compress it. On wireless LAN you are looking at around 50mbps In order to get the file so compressed you will need to apply many settings that will fry the machine for the encode When it comes to playback As no laptop have 8K resolution you will look at a screen with HMDMI 2.1 currently over £3K as the bandwidth of uncompressed RGB is massive For streaming to work reliably at 50 mbps it is also a very high requirement if you wanted to use an online service So the only platform that will actually playback your 8K file is going to be a Tv either from USB or HDMI 2.1 or from a very strong LAN connection The rest of the devices will playback a scaled version of your file But then why exactly did you shoot 8K I guess it is my question Today 4K works fine with Tv sets also in HDR bandwidth requirements are 15-20 mbps which is aligned to performance of most wireless LAN and internet connections I do believe there may be a case of scaling down to 4K for delivery more pixels can help but then I am ok to have the camera doing it internally for me
  20. You are not going to produce those files as output of your process. You are likely to output x265 10 bits 420 with good level of compression or your files will be huge Those output files won’t play on majority of machines out there Sent from my iPhone using Tapatalk
  21. If the monitor has a mount top and bottom it is possible to put it behind the camera someone has done it already Sent from my iPhone using Tapatalk
  22. I do not know I had a long discussion on the handles that are bent forward and are useless but I was told this was the design feedback from 'experts' I then asked why the A7S3 for example does not have handles angled forward and did not get an answer You can of course use a longer arm and put the monitor back mounted the rig becomes elongated like a videocamera...
  23. No hardware will be able to decode 8k60fps This whole 8K idea is a bit too early considering the fact 4K is just now picking up and is only covered by online streaming and no broadcast Obviously Tv is changing but the time until it becomes completely digital is very very long and anything that gets done needs to go on satellite and aerial Phones support HDR though so we need to see who gets there first For me 4k60 is plenty to take and underwater output in 30p is totally fine things move slowly most times. If we talk about birds, squirrels rabbits ok even 120fps but fish is really slow in comparison
  24. CineD results a different story: https://www.cined.com/canon-eos-r5-c-lab-test-rolling-shutter-dynamic-range-and-latitude/[/url] The Canon EOS R5 C shows a mixed bag in our lab test. Rolling shutter values are quite good (but not exceptional), the internally recorded Canon 12 bit Cinema RAW Light LT is super noisy – so you have to plan applying noise reduction in post. The internally recorded 10bit 8K H265 CLog3 (no CLog 2 available yet) shows a real improvement over the Canon EOS R5, but dynamic range is still quite average looking at the competition from Panasonic and Sony in that price bracket. Latitude results show 7 stops, confirming the average dynamic range results. For a consumer full frame camera, 8 stops is the benchmark for now. Sent from my iPhone using Tapatalk Sent from my iPhone using Tapatalk
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