Jump to content

Interceptor121

Member
  • Content Count

    4931
  • Joined

  • Last visited

  • Days Won

    207

Everything posted by Interceptor121

  1. If you want to pressure test your rig you need to take it to a dry diving chamber A vacuum detection system doesn’t prove anything with regards to ability to withstand pressure as that is linked to the collapse/damage of materials not the failure of a seal Sent from my iPhone using Tapatalk
  2. Magnification in photographic terms is the ratio of the frame size in the image and the sensor size If you take your macro lens on land and go as close as you can to a ruler and take a shot then put that macro port underwater go as close as you can you will get the same frame size but from further behind The photographic magnification didn’t change but the apparent magnification standing at the same distance did This however is irrelevant to your objective as photographer in terms of frame size and photographic magnification Sent from my iPhone using Tapatalk
  3. The apparent focal length increases but the working distance also increases so you get the same magnification from further away With a dome port you are closer but the field if view is the same as topside Magnification doesn’t change but with the flat port you are further away Generally for true macro you don’t want to be closer but for a zoom lens that is not a macro lens where you could be at half a meter a dome may help Your position changes not the maximum magnification you can get Sent from my iPhone using Tapatalk
  4. Maybe we see the flashing differently but the point is flashing only means air is being sucked out once solid it has reached at least the required differential pressure You should not use the camera if the light is not solid as the system is not armed The moisture sensor though acts independently Sent from my iPhone using Tapatalk
  5. A flat port increases magnification and working distance resulting in exactly the same magnification that you have on land With a dome port assuming all is correct you will get the same situation at the land working distance Hopefully this was clear enough Sent from my iPhone using Tapatalk
  6. the light does not go into flashing green it goes from blue to amber when you start pumping and then to solid green I do not recall seeing any official statement about the pressure differential which in any case will not be strong in the order of 100-200 mbar Note that if you keep pumping it does not get more green but if you had a flood this pressure delta will make the water go in quicker
  7. I am not a user of retra strobes however having had several discussions with them I think it is commendable that they continue to bring innovation out. I also think it is understandable that older model are being discontiuned once stock is sold out as long as they honour the warranty this is nothing strange Like anything a consumer needs to decide if the new features are worth a change bearing in mind that offloading their now discontinued item can be costly but nothing lasts forever. I tend to keep my strobes for at least 5 years I do not use them enough to justify changing them quicker and for cameras in my underwater housing this is at least 3 years but usually more like 5 Any time I buy something I do a lot of research to be sure I am happy with the limitations and trade off of what I got and then simply ignore new products coming out. However I also recognise that if I bought a product that did not fit the bill I would be looking for a change much quicker. It has not happened yet though
  8. I am not surprised. Ground staff funny enough do not seem to know their own airlines rules. And some airports are very keen on charges, A typical example is equipment containing lithium batteries. You go on the airline website and it tells you it is fine to check it in as long as there is a protection mechanism to prevent activation but the spares need to go in the carry on I made the mistake of telling turkish airlines about my dive light and ended up carrying 3kg more in handluggage which was more than allowed but they let me do it anyway. I spent half hour on the phone to avianca to confirm i can pack diving equipment as standard cargo and exceed the linear limit for oversize but she told me not the clause on oversize takes precedence on the diving one. I said but then if I buy a sport equipment allowance I am actually getting another bag as your website says. It went nowhere in the end I bought the sport equipment as I prefer to check in stuff and not break my back in hand luggage so this did not matter.
  9. An image with subject only in the centre is not represantive of image quality by any means And even your answer is brutally wrong because having the right extension is paramount to image quality. You are putting a lens behind a dome with a specific objective which is to preserve field of view. If you get the extension totally wrong you may end up with a flat port this not only kills field of view but also creates chromatic aberrations This is why many images of rectilinear lenses underwater with systems like seafrogs that do not allow to position the dome properly look always terrible In fact it is not about the money is about the knowledge. If you make a choice of wanting to use a small port, which in fact I have done myself using the 180mm wide angle port, you need to choose the lenses that best fit that port which means those that are built in a way to be more compatible. As consequence such lenses get the * for best performance on the nauticam chart even with the smaller dome while others don't even if they offer a smaller field of view. For E-mount the Sony primes 20mm G and 24mm GM fall in this category and in my view also the 24-70GM2. The tamron 1728 and 20-40 do very well and won't benefit much out of larger port. A bunch of other sony lenses will not do so well with a smaller port because their working distance is long or the lens is small and the working distance in proportion is too long requiring a larger radius dome The Sony 20-70mm G is not a cheap lens at all. It costs £1,399 in UK the Tamron 20-40mm instead costs £879 and in UK is even overpriced. Now exactly the opposite of what you said you will be spending less with the tamron and get better performance with the 180mm dome. I can shoot this lens at f/5.6 and it looks good. You will be giving up the range between 40 and 70 for a fish portrait compared to a longer lens. It would be nice to have an all around lens that has a lot of zoom and works with a relatively small wide angle port but the Sony 20-70mm is not that lens otherwise I would have bought it already
  10. Focussing inside the glass occurs only if the extension is too long for the specific dome it is not related to the dome radius of its own You can have a relatively narrow lens with an extension longer than necessary and focus on the dome however the loss of field view means the dome will have pincushion distortion and the edges will pull Many lenses due to the lack of close working distance loose substantially field of view so they effective focal length is no longer 20mm or what you think This is why a lens that focusses close combined with a correctly positioned dome bears better result and even so you can bet that your fisheye lens is nowhere near 180 degrees and your wide angle lens of 20mm is actually 22-24mm field of view due to to close focus point
  11. There is a challenge driven by the master lens itself Other than the sony 28-60mm that yes it is not very sharp at 28mm but improves later there are no small 28-60 or 28-70 lenses around on full frame As the master lens front element has a 67 mm or larger filter thread the adapters grow in size It would be interesting to test this new solution against the Canon 8-15mm and the new Kenko HDX Pro teleconverter (which I have) to see how it does Consider that the kenko solution adds a 20mm extension ring to the dome and that the tc itself is not heavy either so overall the solution is large but nowhere near 2kg as the dome is less than 700 grams My experience with the TC is quite positive however when you zoom in the quality drops and so does the depth of field so you need to stop down more and more however at wide end I do not see any difference compared to the naked lens and the field of view is actually wider (which is bizarre) and even more distorted.
  12. Not sure This adapter is going to be heavy the tokina adapted remains a strong and cost effective proposition for dx and mft This new port seems very much a full frame option we shall see Sent from my iPhone using Tapatalk
  13. One issues of fisheye lenses is that the vertical field of view is smaller than a rectilinear lens of the same focal length as I demonstrated before If instead of a shark you are shooting a school of barracudas or a bait ball that is circular you may need to step back if you only have a fisheye lens with reduced field of view as it happens with the likes of WACP or WWL lenses where the vertical field of view is smaller than a 20mm lens This is why a zoom fisheye that goes all the way to 175 degrees diagonal (no diagonal fisheye is 180 degrees) and allows zoom to maybe down to 130 degrees is nice. If it did 100 to 175 would be like the tokina on DX and as Phil said at the beginning that would be awesome I am looking forward to understanding more about the compatibility of this adapter
  14. Nauticam has a zoom gear on their website but the port chart not updated yet As previously discussed the relative short length of this lens combined with the working distance of 30cm means a very large radius is required. There will be a good distance close to the 180mm/DP170 dome where the lens will not be able to focus and I am not clear what the impact will be on IQ but I am not over confident that this will work well The Sony 24-70GM2 can focus right on the 180mm dome but yet it is not marked as optimal while the 250 port is. As as I can see the 24-70gm2 works really well. Yes 24mm is not as wide as you would want I have now a Tamron 20-40mm that works perfectly with the 180mm dome and I have no plans to invest in the 20-70mm G lens
  15. Nauticam went and tested this in Palau I think? Maybe they don’t have lots of test data Fisheye conversion lens with zoom goes against adapted fisheye with teleconverter. In many cases people were not happy with a teleconverter however if the difference is 3 kg in weight I would still prefer a teleconverter to this We need to see the zoom range and lens compatibility to see what is the position on the market Sent from my iPhone using Tapatalk
  16. https://www.nauticam.com/products/n100-0-36x-wide-angle-conversion-port-compact-wacp-c Sent from my iPhone using Tapatalk
  17. Excellent 3 degrees more lol That was not the point of my post Sent from my iPhone using Tapatalk
  18. Thanks Paolo June is wet season not good for hammerheads. Water is 25 and thermocline is deep at 26 meters I am looking for fish schools and silky sharks which are there with warm water 15x1.6 corresponds to my WWL-1 set up. For hammerheads you need to go January to March but that is not the purpose of this specific trip Thank you for your feedback Sent from my iPhone using Tapatalk
  19. I agree the centre is magnified and pops. Fisheye lenses underwater like on land are to shoot close that is why they focus really really close It is also correct however to remind ourselves that 130 180 degrees is pure theory and normally there is nothing interesting in the extreme edges. The edges are a problem only when they look ugly I do not think Chris was saying that you should shoot rectilinear and neither am I however we need to calm down with claims such as The lens is x stop sharper at the edges for the same diagonal field of view The statement above is pure fantasy as there are not rectilinear lenses that exceed 120 degrees diagonal so the comparison is not even possible. I wish this misleading and incorrect marketing approach is abandoned asap as it makes people think about something that practially does not exist and is irrelevant if it did
  20. Impressed with this lens You can shoot f/5.6 and it is still holding up. F/4 is too much. F/8 sweet spot for most cases Full frame does not seem to mean shooting at f/16 if you have the right lens
  21. That's right the whole 180 degrees 98 degree is a bit of an illusion This is an image taken on a tripod with my Tamron 17-28mm at 17mm On the same tripod position this is the Canon 8-15mm with Kenko 1.4X teleconverter which is 21mm. In theory the first lens would have had 93 degrees and the second 101 degrees horizontal however with measuring tape at hand this was in reality much less with a shooting distance of 1.35 meters. As lenses behind dome are in reality focussing much closer this means the underwater field of view is significantly narrower than advertised. You can also see a few other things. 1. The rectilinear lens at 17mm has significantly more field of view on the vertical axis 2. The centre of the fisheye lens image is magnified 3. The diagonals are heavily compressed and mostly contain something that is not really that relevant In my tests of the Canon 8-15mm with kenko teleconverter I have seen that the teleconverter is not the same as cropping the image. The resulting output at 15mm is actually wider than the lens at 15mm and the quality is identical However when you zoom in the quality starts to drop as it can be seen here the Tamron 17mm is significantly sharper everywehere and especially at the edges and this is my same experience underwater. We should not get confused by the barrel distortion effect when we look at field of view nor sharpness as fisheye lenses are in fact not very sharp at all at the edges and remain so underwater. The difference is that the centre of the frame pops so the image looks different. To get sharp edges at close range you will be shooting at least f/16 it does not matter fisheye or dome, WACP or any other adapter. Far targets will look fine at f/11 or even f/8. I look forward to knowing more about this Nauticam adapter however if the weight is over 2 Kg at it seems I do not think I will consider it for my A1
  22. Subsee +5 is good for video you are shooting at 15-20 cm which can be done handheld in certain situations More requires some form of tripod Sent from my iPhone using Tapatalk
  23. Olympus is actually correctly implementing half stops The difference between 1/350 and 1/400 is 0.2 Ev and 1/400 is not a full stop on the nominal table (1/500) If 1/400 matters to you then 1/3 are required I can’t disagree with this implementation Sent from my iPhone using Tapatalk
  24. If the camera is smart even with half it should reach the max 1/400 if not the case this is a pity but you could set up to 1/400 and then change the switch
×
×
  • Create New...