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General Discussion => Hobbies & Crafts => Topic started by: Rik on November 15, 2009, 17:49

Title: Recipocity failure in digital cameras
Post by: Rik on November 15, 2009, 17:49
Has anyone ever come across a reference to this? It was always an issue in film photography with long exposures, but I've never seen it referred to in connection with digital photography.
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 15, 2009, 17:53
Well, it says here not to worry about it:

http://malektips.com/digital_photography_0039.html

Further:

http://photo.net/nikon-camera-forum/00IdiZ
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 15, 2009, 17:59
Useful, thanks. I like the idea of cancelling with a blank frame...
Title: Re: Recipocity failure in digital cameras
Post by: Clive on November 15, 2009, 19:44
It was the bane of astrophotographers who wished to take long exposures to capture ever dimmer objects.  A way around it was to  hypersensitize the film by bathing it in hydrogen gas for a few hours.  Best results were obtained with Technical Pan.
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 15, 2009, 20:41
I actually have no idea whatsoever what this thread is about!  :stars: :)x
Title: Re: Recipocity failure in digital cameras
Post by: Clive on November 15, 2009, 20:46
In a nutshell, long exposures cause fogging even in the dark.  :)
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 15, 2009, 21:44
Ah, OK, and digital cameras don't do that.  :)
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 16, 2009, 09:17
I'd describe it differently. Normally, photographic exposures are linear, eg you double the shutter speed, you open up the lens by a stop. This is only true, though, for a limited range of exposure times, too short (rare) or too long, and the film became less sensitive. Anything much above about 30 seconds required compensation, and there was no easy way to work out how much.
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 16, 2009, 09:55
But, digitals are immune, yes?
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 16, 2009, 10:12
Yes, they just get noisy instead, but you can cancel that in a number of ways.
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 16, 2009, 10:33
Somehow, I don't think it's something I'll need to be concerned about.  :)
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 16, 2009, 11:02
Only if you get into night shooting.
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 16, 2009, 11:48
I need go get back into day shooting first.  :)
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 16, 2009, 11:48
Most people shoot birds.  :o:
Title: Re: Recipocity failure in digital cameras
Post by: Simon on November 16, 2009, 11:53
Only the ones that sht on the windscreen.  But it's just as easy go not go out with them again.  :)x
Title: Re: Recipocity failure in digital cameras
Post by: Rik on November 16, 2009, 11:53
 :-X ;D