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10-02-2006, 06:16 PM   #16
Ole
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The examples were not cropped.

10-03-2006, 07:31 AM   #17
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QuoteOriginally posted by thazooo Quote
There maybe a very slight change in DOF because of the smaller sensor, this shows up more in the small digicams rather than the dslr.
This doesn't make sense - dof is an optical quality of the lens, and has absolutely nothing to do with how the image is being registered. If you removed the emulsion on a strip of film except in an area equivalent to the digital sensor, the dof wouldn't change. The reason P&S digitals have large dof isn't due to the tiny sensor, it's because of the optical qualities of the very short focal length lens they can then use with that sensor. I'm sure a digital sensor isn't capable of changing the rules of physics and light!

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10-03-2006, 03:41 PM   #18
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Well, foxglove, you're not completely correct. There's such thing as "circle of confusion".
http://en.wikipedia.org/wiki/Circle_of_confusion
10-04-2006, 05:19 AM   #19
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QuoteOriginally posted by Edvinas Quote
Well, foxglove, you're not completely correct.
It certainly wouldn't be ther first time!

QuoteQuote:
There's such thing as "circle of confusion".
Interesting! Now I may be confused (circularly or not) but doesn't this mean that APS-C sensors actually have a smaller dof that 35mm, all else being equal? From the Wiki entry: "...the optical sharpness demands on the optical system are more severe for smaller film formats, because the enlargement factor is bigger." That sounds to me as though if you enlarged the APS-C and film images to the same size, more of the image from the digital would appear to be oof. Of course, I was arguing earlier that comparing the two full-frame isn't really useful, as the APS-C is essentially a crop of the 35mm, but it's too early in the morning for me to figure out how APS-C vs APS-C-sized-crop-of-35mm relate to one another taking this whole circle of confusion thing into account!

I should sit down and think this through properly, and read some more, but really this is just an interesting intellectual exercise - as long as I'm happy with the images I make, the physics doesn't really matter. I don't think I'm a good enough photographer to start worrying about these details!

Julie

10-04-2006, 02:12 PM   #20
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QuoteOriginally posted by foxglove Quote
This doesn't make sense - dof is an optical quality of the lens, and has absolutely nothing to do with how the image is being registered. If you removed the emulsion on a strip of film except in an area equivalent to the digital sensor, the dof wouldn't change. The reason P&S digitals have large dof isn't due to the tiny sensor, it's because of the optical qualities of the very short focal length lens they can then use with that sensor. I'm sure a digital sensor isn't capable of changing the rules of physics and light!

Julie
Guess I should have thrown the circle of confusion in on my comment :-)
The DOF thing shows hardly at all on my D or Ds until I get into macro mode or start using tubes. I can notice it there.

"as long as I'm happy with the images I make, the physics doesn't really matter."

Great philosophy, it's all about the images :-)
10-04-2006, 02:31 PM   #21
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This have been a very interesting thread and much learned. I really enjoy the technical side of photography but I also know that I can be a bit carried away. When I get my head around something new as with the information in this thread I have to discuss it with someone, mostly my poor wife. Being technically minded she pick up on it fast and then bring me down to earth with a “wow, with this new information you be able to take twice as good photos”.

Cheers

Eddie
10-05-2006, 06:13 AM   #22
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QuoteOriginally posted by mingdie Quote
This have been a very interesting thread and much learned.
That's the great thing about these forums, there's always someone with a new and interesting bit of info, happy to share and explain.

QuoteQuote:
When I get my head around something new as with the information in this thread I have to discuss it with someone, mostly my poor wife. Being technically minded she pick up on it fast and then bring me down to earth with a “wow, with this new information you be able to take twice as good photos”.
You've got a smart wife! I try to listen to the little voice in my head that says the same, but it's easy to get carried away. I tell myself that thinking about this stuff might keep me from getting Alzheimer's!

Julie
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