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10-24-2009, 02:29 PM   #46
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QuoteOriginally posted by FHPhotographer Quote
Dave, I really only had one question in the OP, but I may have not stated it well, so let me rephrase that question: if I'm standing at point X and looking at several objects clustered around point Y, and I take a photograph that shows a different relationship of the Y objects than the relationship I see, and assuming that the 35mm I am using is a "normal" lens, do I need to use a +normal or a -normal lens to be replicate the objects relationship that I see?
Brian
Brian, Here's an example I just put together. I stood up & took a couple of snaps out my window at 18mm and 55mm. Here's the result:


The apparent size relationship between the lamp and house in the background didn't vary with lens focal length regardless of print size or lens length. The size relationship would only change if I took the photo from a different location. The lamp would look even bigger if I moved closer to it.

I think some perceived change of relative size can be forced by changing the frame around an image....the size of the frame the camera looks through is not necessarily the same size frame that you look through. Perhaps that's what's causing the perception effect you describe.

I guess what you are describing is more mental than physical. Perhaps you can go out there and try a few lenses. I'd like to hear what you find out.

Dave in Iowa

10-24-2009, 11:19 PM   #47
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QuoteOriginally posted by FHPhotographer Quote
I just went back out to the site to make sure I wasn't mis-remembering, and I still see one thing while the camera records it differently.

Since what I saw, and what I photographed, were from the same position, then the position of the camera isn't as variable
As I said before, that's just flat-out impossible. If the relative positions or sizes of any objects changed, then a change in position is the *only* thing that can have caused that. I know you were probably trying very hard to take the picture from the same spot, but the focal plane of camera is severla inches in front of your eyes, and a couple of inches lower to. It would surprise me to find that this makes a noticeable difference, but if you controlled all other variables, that' the only one left. Focal length, again, does *not* play into this.

QuoteQuote:
That brings me back to the original question: if I want to capture the image as seen, do I use a wider-than-35 lens or a narrower-than-35 (telephoto) lens? Or will the answer forever be, "it depends" ?
No, the answer will forever be, "it doesn't matter; focal length has no effect on linear perspective (relative size, shape, and positions of objects)".
10-25-2009, 02:44 AM   #48
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Marc, we're reached an impasse. I'll accept that changing the lens won't change the outcome (perspective of a recorded image) if you accept that the camera recorded an image that shows a relationship among the viewed objects that is different than the relationship I saw,
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10-25-2009, 09:25 AM   #49
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QuoteOriginally posted by FHPhotographer Quote
Marc, we're reached an impasse. I'll accept that changing the lens won't change the outcome (perspective of a recorded image) if you accept that the camera recorded an image that shows a relationship among the viewed objects that is different than the relationship I saw
I can accept the camera recorded an image with a different relationship among viewed objects than what you saw if and only if the camera's focal plane was in a different location than your eyes', because the laws of physics do not permit any other explanation.

10-25-2009, 01:06 PM   #50
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I suggest you take a 4:5 photo with your "normal" lens & make an 8 x 10" print of it. Return to exactly the spot where you took the photo & close one eye - you'll be able to find a position to hold the print such that it *exactly* overlays the scene.

Further, you'll be able to do this for a variety of focal lengths - our perception of what's normal is flexible. This is an iron-clad way of determining your personal "normal" lens.


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Last edited by newarts; 10-25-2009 at 02:33 PM.
10-25-2009, 04:11 PM   #51
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Marc, if quantum mechanics has shown us anything, the "laws of physics" don't always apply.

As Sky Masterson once said, "One of these days in your travels, a guy is going to show you a brand-new deck of cards on which the seal is not yet broken. Then this guy is going to offer to bet you that he can make the jack of spades jump out of this brand-new deck of cards and squirt cider in your ear. But, son, do not accept this bet, because as sure as you stand there, you're going to wind up with an ear full of cider."
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10-25-2009, 04:19 PM   #52
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Brian, you mentioned before that enlarging the image on you LCD seemed to give you what you wanted. Obviously, enlarging the image on the LCD couldn't have made the relationship between the power pole and the mountains different; it just made everything bigger. If that is really the effect you are looking for, then you need to use a longer lens.

As with enlarging the image on the LCD, changing the lens cannot change the relationship between the power pole and the mountains. It may seem to, but it is just a trick of the mind. I explained this once earlier, but the explanation sounds confusing. Let me try again. Your brain expects nearer objects to grow in size faster then farther objects as you approach them. When you enlarge an image within the same frame (for example by hitting + for the preview, or switching to a longer lens), this doesn't happen, so it can trick your brain into feeling like the nearer object actually got smaller compared to the farther object, even though really it only failed to get larger compared to the farther object (of course, this works in reverse for wide angle lenses compared to backing up). I don't know if that helps you, but that's what I can come up with by what you said.

I still think you would be better off taking a full sized print back to the spot with the lens you have now to get a better idea of how you will feel about the capture than looking through your viewfinder (entirely misleading) or at your image preview (probably misleading).
10-25-2009, 05:45 PM   #53
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QuoteOriginally posted by FHPhotographer Quote
Marc, if quantum mechanics has shown us anything, the "laws of physics" don't always apply.

As Sky Masterson once said, "One of these days in your travels, a guy is going to show you a brand-new deck of cards on which the seal is not yet broken. Then this guy is going to offer to bet you that he can make the jack of spades jump out of this brand-new deck of cards and squirt cider in your ear. But, son, do not accept this bet, because as sure as you stand there, you're going to wind up with an ear full of cider."
OK. Someday, someone using heretofore unknown technology will invent a camera or lens that is capable of altering the relationship between objects depicted. But no camera or lens ever seen up until now can do this. And as long as light continues to travel in a straight line here on earth, that seems likely to remain the case. Maybe a lens with a built-in black hole could change that.

10-25-2009, 06:20 PM   #54
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QuoteOriginally posted by newarts Quote
I suggest you take a 4:5 photo with your "normal" lens & make an 8 x 10" print of it. Return to exactly the spot where you took the photo & close one eye - you'll be able to find a position to hold the print such that it *exactly* overlays the scene.

Further, you'll be able to do this for a variety of focal lengths - our perception of what's normal is flexible. This is an iron-clad way of determining your personal "normal" lens.
Dave in Iowa
You'll need some background in that photo, otherwise it's not going to lead you to a normal perspective.
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