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#1 |
Member
Join Date: Jan 2004
Posts: 62
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I want to reverse a olympus zuiko 50mm f/1,8 on a Powershot a40 to take super-macro foto's. Need advice. Do I need a bigger zoom to minimize vignetting?
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#2 |
Senior Member
Join Date: Jul 2003
Posts: 156
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Is this the lens that you are talking about?
http://www.pbase.com/image/26713754 If it is, here are sample shots of this lens on an a40. These were shot quick just to show magnification (I uploaded them a long time ago) so I didn't put a lot of effort into geting good focus, lighting etc. I am using a 49mm-49mm macro ring and a 52mm to 49mm step ring. You could of course use a 49mm-52mm macro ring. You have to adjust you camera to full zoom to use it. Anything less than full zoom will vinyette with this lens. One shot is just the camera and the other is with the lens. http://www.pbase.com/richardh/a40slrmacro |
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#3 | |
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Join Date: Oct 2002
Posts: 579
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![]() Quote:
http://www.stevesforums.com/phpBB2/v...ic.php?t=15584 CK http://www.cs.mtu.edu/~shene/DigiCam Nikon Coolpix 950/990/995/2500/4500/5700 User Guide |
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#4 |
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Join Date: Jan 2004
Posts: 62
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Thanx for the replies guys. I finally got my Zuiko. But I still don't have a lensadapter. So I must hold the lens in front of the A40. Only a piece of toilet-roll is preventing the lens from touching the Powershot A40.
No problem with vignetting. 3x zoom is enough. But I'm selling my A40 and my next digicam will be the G3. So I'll be using the Zuiko with the G3. I have already experimented with the A40 and Zuiko. This is an example of my eye. Don't with tv and av-cable. ![]() |
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#5 |
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Join Date: Jan 2004
Posts: 62
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#6 |
Senior Member
Join Date: Feb 2004
Posts: 170
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I had thought of trying an eye picture but I never got around to it. This is the reversed lens? Any idea why the one photo makes it appear that there is a dry area on your eye surface?
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#7 |
Senior Member
Join Date: Feb 2004
Posts: 170
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I finally got around to experimenting with a reversed lens. Not
the best lens, just a C-mount video camera wide-zoom lens. I compared it to a Nikon 4T macro lens and to the native Oly C750 supermacro mode. First difference -- the rather small diameter (49mm filter thread) video camera lens had vignetting even at 10x. One big difference was the working distance. The reversed lens needed to be very close to the subject. Probably an inch or less. The 4T was many inches away. The next big difference was the magnification factor. The reversed lens produced more magnification, and I discovered that the shorter the focal length the greater the magnification. Thus as I adjusted the lens from 75mm to 12.5mm the magnification increased significantly. But along with increased magnification the DOF became smaller and more troublesome. It was very difficult to hold the camera in focus. Now would stacking macro lenses produce the same result as the reversed lens? I'll try to have some images posted sometime tomorrow. |
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#8 | |
Member
Join Date: Jan 2004
Posts: 62
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![]() Quote:
The working distance of my lens is 2 inches. Digicam with bigger zoom gives |
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#9 |
Senior Member
Join Date: Feb 2004
Posts: 170
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I would like to think of a target subject that would work well to show both DOF and the magnification factor and be continuous so that unsteady camera holding is not an issue. Maybe that isn't possible.
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#10 |
Senior Member
Join Date: Feb 2004
Posts: 170
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Ok, I finally have some test images up, but they don't really look too good. Hand holding the lens didn't help matters and it is a c-mount video camera lens rather than a 35mm SLR lens. I thought the lens had a 52mm filter thread but it was smaller than that so I didn't have a ring for it.
The set of images is from an Oly C750... http://galt_57.home.att.net/macro.html |
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