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Interceptor121

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Everything posted by Interceptor121

  1. Macro photography is low light by definition as you use small aperture fast shutter and low ISO If you put a focus light in the mix any camera can focus easily all the ideas you need tracking for macro etc for me are more wishful thinking and a proxy for the diver not the subject moving
  2. No it doesn’t work that way the lowest ev is a negative value and the ev are always added. So the range is 11ev + the range so this results in an offset. Say it was 20 to -4 it becomes 31 to 7 ev. Other than the math this is a CIPA test on single AF which maybe is not what you use anyway The negative value is a good proxy for that however performance in continuous mode falls apart much sooner. Cameras employ then other tricks like reducing the shutter speed and therefore the frame rate of your evf to try and focus this generally kills entirely the continuous autofocus that needs high refresh rates All considered the negative ev mentioned remains your only point of reference In general all mirrorless camera switch to contrast detect in low light and the different performance shows how well or how bad they cope in those conditions that are typically different from the normal operating conditions The only real way to see if does or not apply to your use case is a test obviously Sent from my iPhone using Tapatalk
  3. When you look at how focus systems are defined you need to understand how the camera achieves focus Most cameras achieve focus with the lens wide open and the close the aperture when they need to shoot. This means that if you are shooting macro you are effectively at f/2.8 with typically a fast shutter speed say 1/250. This is a scene that has an exposure value of 11 EV at ISO 100 or 5120 lux in essence a sunny day. Your camera will typically have a -Ev rating for single AF (forget about tracking) which is usually something like -4.5 Ev In our case 11-4.5=6.5 the camera will refuse to focus at less than 226 lux which is not that dark after all. Increasing gain (ISO) does not change the camera ability to focus but helps you seeing the LCD and focus manually Looking at your examples Sony A7R4 EV -3 Canon R5 Ev -6 The canon R5 has 3 stops benefit For reference Nikon D500 -4 EV Panasonic S5 -6 EV Nikon Z7II -4 EV So Canon and Panasonic have an edge on Nikon/Sony probably due to the different nature of the autofocus system. Adapted lenses do not perform as well as native
  4. For those who did not understand my previous post what I am saying is that the advice given in the video to shoot wide angle between ISO 100 and 640 will be appropriate for the camera @Alex_Mustard shoots but not on another one that has a different design Nikon cameras use Sony sensor but are designed in a completely different way from Sony or Panasonic cameras that use the same sensor family not only that some sensors are front illuminated and some are back illuminated and those behave differently Finally cameras do not meter the same way so if you take brand A and say -1/3 works well as the camera cannot meter perfectly in water you may find another one where it needs +1/3 Know your camera in detail in essence is the motto
  5. ISO is one of the most misunderstood concepts of digital photography and that is because a camera has only one sensor and therefore only one film. You can't go and change the film you can only proxy that with gain which is what ISO maps to You can't generalise concepts due to the different way sensors are constructed so one camera may be totally fine at 2500 and one be rubbish. Also some cameras are ISO invariant and some are not at all and this influences how you should shoot. Only one thing is for sure an image with too low ISO that is too dark on broad area is worse than one with a small clipped highlight in my opinion If you want to maximised performance in your camera I suggest you study not only DR charts but also input referred noise charts
  6. If it is polycarbonate it cannot be polished if it is hard coated unless you remove the coat altogether It is always a trade off hard coated scratch less but when they do they cannot be repaired. Uncoated scratch less and you are there repairing them a lot on the field but once you are used to is it is all good
  7. 4" dome port or 2" 5 cm width typically out of a 11 cm circle means 57 degrees coverage which is less than 20mm for MFT Any lens will be pushed into it not to vignette creating severe aberrations
  8. 12-45 is not an interesting lens. The 4" dome is also a not terribly interesting port!
  9. The 12-40 as the 12-60 remain very sharp but need a dome and are not wet lens compatible Sent from my iPhone using Tapatalk
  10. Yes exactly as the 14-42mm Sent from my iPhone using Tapatalk
  11. The problem of many shooters is that they do not understand that lenses that are good on land may not be good underwater or be less compact. Underwater I use the 14-42mm lens with WWL-1 a lens that I never use on land. On land I use the 8-18mm and 12-60 both need a dome and they are not compact neither take wet lenses same goes for 12-35 and 12-40mm Then you have the macro 30,45,60 all have a small port And fisheye that in the MFT version takes also a small port So if you want to have a compact set up you need to avoid wide lenses and good standard zoom or you go into dome territory
  12. Generally the filter thread size is an excellent proxy for the non parallax point which is not published. In essence each lens has a filter thread that ensures vignetting will not occur. Smaller the filter thread less recessed the non parallax point. So a lens with a 62mm filter will generally have the non parallax point further away from the front of the lens for the same field of view of a lens with 40mm thread and will have more problemsThe WWL-1 works with lenses that have typically a 40-46mm filter thread you can safely use this as a proxy In addition it works better with lenses that are wider when extended The full frame and APSC zoom are all wider when retracted and have filter threads larger than 58mm you already know this is not going to work You can try a short port with no zoom but that defeats the objective On full frame is not possible to have alternative to the WACP on APSC fisheye zoom with teleconverter cover the same field of view but probably an APSC user would never consider WACP anyway Sent from my iPhone using Tapatalk
  13. The reason why the Sony 28mm full frame works with the WWL-1 is because the lens is very small and has 40mm filter thread which means the WWL-1 is ok with it When you look at APSC there are some lens that might work but full frame is not an option as all lenses are over 62mm so too big once you factor a zoom
  14. So TC 1.4X no effect you can see on the 8-15mm when using an MFT camera which is further cropped but this is at least promising!
  15. Yes but I want something even narrower. In APSC the lens works 10-15mm giving 180 to 115 degrees. I am looking for something to go all the way to 80-90 degrees
  16. I already have the canon fisheye it is a superb lens and I use it currently for my GH5 as zoom fisheye. I have been considering APSC and I would prefer to avoid to buy a new lens. I already have the Nauticam 140mm glass dome so I was thinking of using the Kenko TC that will give me a fisheye zoom of 11.2-21mm range which is very interesting. I know that TC deteriorate to an extent image quality however I think the Canon 8-15mm with the kenko may still be a better optic than the tokina which is after all a mediocre lens. I wonder if anyone has experience comparing those on any format / crop?
  17. Yes it works fine I have seen images from people on my same boat and they were not even advanced Canon ef lenses for Sony work well and there is no need for any native lens Sent from my iPhone using Tapatalk
  18. Sigma sells an adapter for canon EF Nikon adapters for third parties dont support AF Nikon is very captive once you are in you stay in Sent from my iPhone using Tapatalk
  19. Sigma makes MFT Emount SA Lmount Nikon DX FX Canon ef efs They don’t support any of eos M nor nikon Z You get more lenses for a Panasonic full frame than nikon or canon Sent from my iPhone using Tapatalk
  20. I have done several cooperations with photonstophotos that does measurements of DR and noise The mirrorless cameras APSC from canon and nikon have performance usually worse than MFT even in terms of low light I think this is due to severe cost cutting in internal electronics dsp and asic So your example is a perfect one fitting exactly into this picture There seem no intention to produce pro level APSC mirrorless from the two main brands Sent from my iPhone using Tapatalk
  21. The 14 bit issue is probably going to go away some time soon. 4 megapixels mean very little today as the target is online with max 2 megapixels Which is why as you said 20-24 is enough I shoot a lot people landscape deer birds fish night scapes long exposures The use case for full frame is mostly prime lenses not long tele not wide end If you wanted lots of megapixels sure but nobody bothers plenty of event onto gro downgrade to shooting low megapixels or even jpegs to avoid 45mb files I make some nice A3 prints of all sorts there is not a lot to complain I do prefer shooting people with full frame though is more organic and real but underwater shots are better than life mostly Sent from my iPhone using Tapatalk
  22. One thing that I think you guys have missed is that smaller format wider aperture means smaller strobes A pair of prosumer plastic strobes is adequate for MFT borderline for APSC and small for full frame I think you need to look at the whole system beyond housing and ports Perhaps a MFT pro camera is still bulky but a pair of mid sea and sea or inon are less bulky and cheaper than other solutions and with a smaller format will deliver the goods Sent from my iPhone using Tapatalk
  23. Although at same settings a larger sensor produces a higher IQ once you work at constrained depth of field the benefit is zero So your full frame fisheye at f/11 is aspc at f/8 and MFT at f/5.6 Your two stops ISO benefit is gone As a land based full frame user the benefit is in those situations where I can have a different look for example shooting f/2 wt night where f/1 on MFT doesn’t exist Or bright scenes where full well capacity of full frame just gives more detail Underwater those benefits for most dont exist What is different is that some larger cameras are just better camera either for af, battery life functionality Then of course WACP type solutions bring back the gap however they are expensive Sent from my iPhone using Tapatalk
  24. If the lens is not redesigned from scratch the parallax point which is used for the extension calculation does not move So with a mirrorless camera using a lens not designed for mirrorless your extension is longer so even if the housing is more compact there is zero benefit underwater
  25. The flange distance difference between mirrorless and DLSR is usually 20-25mm this in the scheme of things is not significant and if you put an adapter you are back where you started
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