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06/05/2005 11:26:05 PM · #1 |
its on the sides of all the canon SLRs ive seen
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06/05/2005 11:27:41 PM · #2 |
It shows where the focal plane of the camera is located, to give you a fixed reference point for measuring distance precisely in critical focus situations.
Robt.
Message edited by author 2005-06-05 23:28:19.
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06/05/2005 11:30:00 PM · #3 |
| oh ok, thank you for that, i jsut noticed it yesterday and couldnt figure out what it was |
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06/05/2005 11:32:08 PM · #4 |
It's also the starting point for the distance you see in minimum focus distance ratings on lenses. If a lens will focus at 12" minimum, it's 12 inches from this point forward rather than the end of the lens.
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06/05/2005 11:33:01 PM · #5 |
I had a better answer than bear - It goes a little something like this:
All Canon SLRs are manufactured at a factory on Saturn that utilizes imported Martian slave labor. All the cameras are stamped with the saturn symbol:
But since the camera bodies are lying on their backs on the conveyor belt, they look like the one you showed when they are upright.
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06/05/2005 11:57:52 PM · #6 |
Originally posted by jmsetzler:
It's also the starting point for the distance you see in minimum focus distance ratings on lenses. If a lens will focus at 12" minimum, it's 12 inches from this point forward rather than the end of the lens. |
Same thing, I believe. If it's not the same thing, then John's correct, not me; it's the reference point for critical focusing, and I *think* that's the focal plane. It certainly is on a view camera. It may be different with small-camera optics, I donno.
Robt.
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06/06/2005 12:58:16 AM · #7 |
| I always thought it was an indicator of the film plane. |
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06/06/2005 01:01:08 AM · #8 |
Originally posted by undieyatch:
I always thought it was an indicator of the film plane. |
Yup, film plane = focal plane, being as how no film in these cams LOL... If your focal plane is anywhere other than your film plane, you have big problems (wink).
Robt.
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06/06/2005 01:02:35 AM · #9 |
Originally posted by undieyatch:
I always thought it was an indicator of the film plane. |
Would be in a film camera.
I understand the more common useage of the info of where the film plane is is for tripod mounting for panarama shots. If the film plane is over the center of the tripod then the pano shots will all be properly aligned.
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06/06/2005 01:08:13 AM · #10 |
Originally posted by Prof_Fate:
Originally posted by undieyatch:
I always thought it was an indicator of the film plane. |
Would be in a film camera.
I understand the more common useage of the info of where the film plane is is for tripod mounting for panarama shots. If the film plane is over the center of the tripod then the pano shots will all be properly aligned. |
That's certainly a usage of it, but you also got to have the tripod mount centered under the lens barrel as well... But these marks go way back for use in critical-focus situations; we used 'em allt he time when doing stuff liek photography of architetcural models on 35mm slide film, where we had to carefully calculate our precise point of focus to have the DOF spread precisely where we needed it.
Robt.
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