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Paul Kay

Member Since 27 Nov 2003
Offline Last Active Today, 01:32 AM

#361872 Expose to the right?

Posted by Paul Kay on 06 June 2015 - 01:20 AM

When digital information is underexposed, chips will strain to record information in the deeper values, and in doing so will produce digital noise.

Ummmm. The darkest areas in the image will be just that - dark. Noise is only produced when you increase the gain (i.e. amplify the signal), so brightening/lightening shadow areas will increase their noise level - very simple. If they are important (more so than highlights) then underexposing them will lead to increased noise when adjusting later. Its got nothing to do with ETTR and lots to do with exposing for your preconceived requirement of output. ETTR in itself is in essence overexposing and as I have said before, can lead to tonal anomalies. So correct exposure must be made on the basis of the subject. Until we get sensors able to record much wider contrast ratios we are always going to be compromising somewhere. I don't see any real advantage to ETTR even in the low contrast conditions (which we compensate for by using flash) underwater. Gurus are great but actual practice is even better IMO.

#361645 Expose to the right?

Posted by Paul Kay on 30 May 2015 - 12:02 PM

I have tried experimenting with ETTR and 'normal' exposure. My personal conclusion is that ETTR offers little if any advantages in practice. My opinion FWIW, is that any increased information supplied by the biased exposure is IMO often undermined by subtle but often irritating shifts in tonality produced when readjusting exposure in post, which then require additional adjustment and on occasion I have found that they cannot be thoroughly compensated for. Blown highlights on the other hand are blown. In situations where the contrast is far too high for the sensor to handle I tend to try to decide what can be blown, if anything, and expose accordingly.


On the subject of ISO, I tend, on my land cameras (digital Leicas), never to adjust from base ISO (160) and adjust/compensate underexposure in post. If you think about it, increasing ISO is pre-setting another adjustment in-camera - in this case 'gain'. Software has become good enough to allow 'gain' to be applied afterwards, to an underexposed shot. In many circumstances anyway. Problems do occur if too much ''gain is applied to the deepest shadows where banding can occur. With the Leicas this is almost negligible, on my Canons it can be a problem - clearly they are slightly different somehow (CCD vs. CMOS?).


And when all is said and done I've also tried experimenting with 'inadequate exposure' and find that post processing can actually produce very acceptable results from mis-judged exposures. My own personal rules on photographic technique are that there are no rules. Photography is practical, if in doubt about what something will produce, try it and be objective about the results. It can be surprising and disconcerting.  

#345986 Physically small intervalometer

Posted by Paul Kay on 10 April 2014 - 12:49 PM

Hey Paul, I have a few questions for you if you have a moment:


1. How did it work for you?

2. Obviously you would have to set it before you close the housing, how did you control it?

3. Does the trigger button control when it starts and stops?
4. Has anyone tried Magic Lantern's TL?


I have 3x 7d's that I would like to experiment with, but I would like a more secure method with my 1DX. Thank you ahead of time for any information you can provide.

1. Worked fine on a 5D2

2. Yes preset it and accept some 'blank or irrelevant images'

3. On the Canon intervalometer its the 'start' button I think (I'll have to dig it out from the box its stored in if you want me to check, but its fairly obvious).

4. I haven't - looks like others have.

#340809 BBC Natural History Request

Posted by Paul Kay on 18 December 2013 - 03:59 AM

You could try asking them to 'swap' it for a piece of 'similar quality' footage and request the same rights over it. I'll bet they don't go for it though......

#335832 Glass Dome Port Repair

Posted by Paul Kay on 15 August 2013 - 03:22 AM

Glass usually require special polishing and the problem is that grinding the damage away effectively can lead to heat build up which can shatter the glass - I know! But it is as you say, worth a try - find a glass repair specialist if you can.


Why not ask the Aquatica about it? It may still be cheaper to have a new glass dome fitted than repace the whole port.

#332432 Animal movies: Should they be real or embellished through artistic license?

Posted by Paul Kay on 05 June 2013 - 11:51 PM

 I guess  the question is whether movie magic should be reserved for fiction, and natural history documentaries should endeavor to retain a certain sense of truth.

As I see it, the problem IS defining truth. There is often an emphasis on filming 'rare' or previously unseen/unrecorded events in documentary film making. This in itself skews the viewer's perception of the natural world, as do many stills photographs. We seem to live in an increasingly 'virtual' world (laser pistols were used at the Olympics instead of air pistols as an example - do they really form part of a physical sport I wonder?) and the lines between fact, representation and fiction are IMHO blurring more than ever. I suppose my take is that if it does some good and it raises profiles and safeguards and allows animals to get on with living in the wild, then so be it. Claiming any natural history documentary is 'true to life' is actually quite difficult as any editing will form an impression in the viewer's mind which is potentially distorted by the condensation of time if nothing else. I suppose that claiming 'true to life' is where the dishonesty can appear - films and documentaries are all representational at the end of the day and it is important to appreciate this when viewing them and enjoy them for what they are.

#330964 An open apology

Posted by Paul Kay on 07 May 2013 - 12:04 AM

More interesting info: http://www.theregist..._act_explained/

#330645 An open apology

Posted by Paul Kay on 01 May 2013 - 01:25 AM

Sign the petition on the government's own site: Stop Legalised Theft of Copyrighted Works - e-petitions

#330562 An open apology

Posted by Paul Kay on 29 April 2013 - 11:53 PM

I imagine that this will be challenged in the EU as it will affect many non-UK photographer's too and will undoubtedly enrich lawyers with the potential violations and infringements that it will potentially lead to. I would say that this is a case of the insane running the asylum but I'm not sure that the word running is at all applicable. Why are we governed by such morons?

#327925 Nikon AF-S Nikkor 24mm f/1.4G ED Wide Angle Lens for underwater

Posted by Paul Kay on 15 March 2013 - 03:17 AM

You may struggle with it behind a minidome - I tried a small dome at first but now use  my 24/1.4 behind either a (Seacam) WidePort or Superdome.

#327753 Nikon AF-S Nikkor 24mm f/1.4G ED Wide Angle Lens for underwater

Posted by Paul Kay on 13 March 2013 - 03:03 AM

I use the Canon 24/1.4 - it gives a very bright viewfinder image but cannot be used at fast apertures due to being behind a dome port. As a 24mm lens with fast AF and a bright viewfinder it should be great though.

#326071 British marine life photo gallery on Discover Wildlife.com (BBC Wildlife)

Posted by Paul Kay on 12 February 2013 - 01:30 AM

Am curious about the Yarell's blenny shot- do you get many sightings of these little guys?

Hi Damo

Yes, mostly in Scotland, but I have seen them in north Wales too (I think the largest caught by an angler was in north Wales). I don't think I've actually seen one in Ireland though but I haven't dived much north of Mayo.

#325399 British marine life photo gallery on Discover Wildlife.com (BBC Wildlife)

Posted by Paul Kay on 31 January 2013 - 06:31 AM

I've just been notified that the gallery of images I supplied has now been put online at:


#319368 Diopter for Canon 16-35; Schneider or Aquaphot?

Posted by Paul Kay on 29 October 2012 - 12:38 AM

B&W = Schneider and if they make an 82mm it should be available here in the UK as there is a B&W importer (you could try SpeedGraphic. FWIW I've tried using achromat diopters and none achromats and have found little difference in actual performance. 11" is pretty good as a close focus distance especially behind a large dome (its measured from the focal plane don't forget) and the reduced angle of view, increased aberrations and lack of infinity focus make me wonder if its worth bothering.....

#318196 Flying Octopuses - comments on the proliferation of these images

Posted by Paul Kay on 11 October 2012 - 07:42 AM

At what point does an animal reacting to our presence shade into unacceptable disturbance?

I have to say that I have worried about this for a few years, particularly when seeing the efforts that terrestrial wildlife potographers go to, to avoid disturbing their subjects. Our subjects almost always know that we are there...

Its a good question because you are quite right, our subjects genrally do know we are around (at least those able to do so). So is our unavoidable presence the limit of acceptability? Should we offer incentives to subject matter ('baiting' as used by our terrestrial counterparts), use remote cameras (I suspect some creatures can tell that electrical or even metallic systems are presnt too) or simply touch nothing and disturb as little as is possible? Of course our presence pales into absolute insignificance compared to the 'adjustments' carried out by commercial fisheries so perhaps we shouldn't be too pedantic?