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03-27-2010, 04:23 PM   #16
Ira
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QuoteOriginally posted by NecroticSoldier Quote
Haha thanks, and... CONFUSION AGAIN... ;( The human eye is magical, that's why.
You just keep your eye out for those Hooters girls, okay?

03-27-2010, 04:37 PM   #17
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QuoteOriginally posted by Ira Quote
You just keep your eye out for those Hooters girls, okay?
Never! I'll look at some hoots instead (OWLS) ;D!
03-27-2010, 05:54 PM   #18
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QuoteOriginally posted by NecroticSoldier Quote
Wow, yeah I have thought about it like how some of the answers explained. I should have been a tiny bit more specific, and I used the wrong words to describe what I was getting at... I meant when I looked at around 50-55mm the object in the viewfinder was as big as when I looked at it without the viewfinder.
That's pretty much what I assumed, since it's the only sense in which 55mm makes sense as an answer/ Although that answer is only accurate for the models with the larger viewfinders - KXXD, K-7. For the Kx and other smaller viewfinder cameras, 55mm is still not long enough to provide 100% magnification. According the specs, it's 85% magnification with a 50mm lens. i don't know for sure how the math works, but I would assume you really more like 60-70 as I said to reach 100% magnification.

The deal is that as I said, while we can answer the question this way, it really isn't a relevant answer, as "how big objects appears in the viewfinder" has no relationship whatsoever to how it looks in the picture. You could stick a giant magnifier on your viewfinder to achieve 100% magnification with an 18mm lens (say), but it's still going to take a wide angle picture just like it would without that giant magnifier.

QuoteQuote:
I know it can never match our FOV
Oh, sure it can - *if* you have an amazingly wide angle lens. Or if you define "FOV" to not mean everything you can take in, but some other subjective way.
03-27-2010, 06:41 PM   #19
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QuoteOriginally posted by Marc Sabatella Quote
That's pretty much what I assumed, since it's the only sense in which 55mm makes sense as an answer/ Although that answer is only accurate for the models with the larger viewfinders - KXXD, K-7. For the Kx and other smaller viewfinder cameras, 55mm is still not long enough to provide 100% magnification. According the specs, it's 85% magnification with a 50mm lens. i don't know for sure how the math works, but I would assume you really more like 60-70 as I said to reach 100% magnification.

The deal is that as I said, while we can answer the question this way, it really isn't a relevant answer, as "how big objects appears in the viewfinder" has no relationship whatsoever to how it looks in the picture. You could stick a giant magnifier on your viewfinder to achieve 100% magnification with an 18mm lens (say), but it's still going to take a wide angle picture just like it would without that giant magnifier.



Oh, sure it can - *if* you have an amazingly wide angle lens. Or if you define "FOV" to not mean everything you can take in, but some other subjective way.
Thanks Marc, yeah I figured it wouldn't matter much because it's just the viewfinder. I guess having it looking life size on paper is a whole different story.

03-27-2010, 07:40 PM   #20
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Vision is nothing like using a lens on a camera. Our eyes never stay still and our brains never stop interpolating (and extrapolating) data, even when locked into the same perspective. But, in the same situation, a camera just snaps the same picture every time.
03-28-2010, 08:30 AM   #21
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For a single eye, at least for me, it is 55mm on the K-7.

To see this, shoot with both eyes open. At 55mm there is no discrepancy between what my left and right eyes see other than depth-of-field and focus.

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03-28-2010, 09:25 AM   #22
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Sure there is - FOV is very different. Hugely different, in fact - your eye sees *far* more than the 55mm lens on the K-7. You're talking only about magnification in the viewfinder, which is an accident of how big your viewfidner happens to be, not anything relevant to photography.
03-28-2010, 11:57 AM   #23
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QuoteOriginally posted by Marc Sabatella Quote
Sure there is - FOV is very different. Hugely different, in fact - your eye sees *far* more than the 55mm lens on the K-7. You're talking only about magnification in the viewfinder, which is an accident of how big your viewfidner happens to be, not anything relevant to photography.
Bingo.
...

03-29-2010, 12:37 AM   #24
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What would be more interesting to know is what focal length looks natural on a certain size of paper seen from a certain distance.
One could pretty easily make a scale of that, it could be used to create an illusion of a more lifelike picture, especially if framing it in a good way.
03-29-2010, 02:22 AM   #25
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QuoteOriginally posted by StarDust Quote
What would be more interesting to know is what focal length looks natural on a certain size of paper seen from a certain distance.
One could pretty easily make a scale of that, it could be used to create an illusion of a more lifelike picture, especially if framing it in a good way.
Artists have been working on this for a few centuries, since the introduction of perspective. The answers they've come up with drive many of our standards of presentation, like the aspect ratios we use for paper, canvas, TV, cine, cameras, and the viewpoint angles (FOV) that are used, which center around 45 degrees, plus or minus 5 degrees. For our APS-C sensors, that translates to lenses around 30-40mm. Yes, boringly normal.

And our display media are sized for that 'normal' FOV. You read an 8x10" paper from a certain distance, hold a coffee-table book further away, stand back from a poster. Shoot with this FOV; view from this distance. There's your scale.

But we humans be variable critters. Consider a cine theatre, the old days, before ultrawide formats. There's a screen up there, maybe 30x20 to 40x30 feet. The projected image comes from a film frame the size of your dSLR sensor. People sit all over the theatre. Very few are 10 feet from the screen. Very few are 60 feet from the screen. Most sit between 20 and 50 feet away, depending on screen size. Unless we've come in late and are forced to sit somewhere we don't like, we've chosen a comfortable viewing distance. The picture looks 'natural' to us (if we're watching it, and not engaged in other activities).

So your idea of a scale of focal lengths, display sizes, and distances, encounters the reality that different people like to see things from different vantages. Yes, for centuries artists have played tricks with perspective to make near scenes seem distant, flat scenes seem round -- but those mostly depend on forcing the audience to take a specific viewpoint. Left to our own devices, we wander around and look at stuff from here and there, closing in to see details, stepping back to get the context, etc. Yes, we can print and mount an image so that a viewer MUST move in or back to grasp it -- but I think that's mostly a matter of how much detail is there, not its aspect or perspective.

For more on viewing and perspective, read up a bit on optical tricks. I'm re-reading the Dover reprint of VISUAL ILLUSIONS by M. Luckiesh. VERY illuminating...
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