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Old Jun 3, 2003, 2:22 AM   #1
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Default Canon A40 close-up lens

Anyone using a close-up lens for their Canon A40? Is it worth the money or am I better off using a cheap magnifying glass anyway? Does anyone have shots of the same subject with and without close-up lens so that I could see the difference?

Would be grateful for any suggestions/answers/replies.
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Old Jun 3, 2003, 4:45 AM   #2
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Default Re: Canon A40 close-up lens

Quote:
Originally Posted by Marble911
Anyone using a close-up lens for their Canon A40? Is it worth the money or am I better off using a cheap magnifying glass anyway? Does anyone have shots of the same subject with and without close-up lens so that I could see the difference?
My Nikon Coolpix 2500 user guide has a page on close-up. In general, the use of close-up lenses brings a camera closer to the subject, and, hence, increases the magnification. You can use one or two close-up lenses, and they do not have to be Canon as long as they are good. Note that the use of close-up lenses is camera independent. Thus, the discussion of my 2500 user guide will help you know more because you will commit a purchase.

CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 user guide
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Old Jun 3, 2003, 5:41 AM   #3
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Thanks for your reply. Had a look at your user guide....quite helpful.

But the lenses have to fit the camera, I guess, so you can attach them to it. Don't know whether other lenses actually fit the canon adapter...

Another thing is, I've got no idea what the numbers usually mean with regard to the magnification of certain lenses (stupid beginner's question, I know)...if they give information at all (couldn't find info on the canon on I was thinking of).
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Old Jun 3, 2003, 8:39 AM   #4
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Default Re: Canon A40 close-up lens

Quote:
Originally Posted by Marble911
Anyone using a close-up lens for their Canon A40? Is it worth the money or am I better off using a cheap magnifying glass anyway? Does anyone have shots of the same subject with and without close-up lens so that I could see the difference?

Would be grateful for any suggestions/answers/replies.
take a look at this for comparison (Minolta D7i):
http://www.pbase.com/kcan/di7_macro

I use a +3 cokin close-up lens
But you can also try with various magnifying glass, it will vignette a lil bit though.
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Old Jun 3, 2003, 2:34 PM   #5
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Quote:
Originally Posted by Marble911
But the lenses have to fit the camera, I guess, so you can attach them to it. Don't know whether other lenses actually fit the canon adapter....
First, you need to know the thread size of Canon's adapter. Then, you simply buy a set of 3 or 4 close-up lenses of the same size. www.2filters.com, www.adorama.com and www.bhphotovideo.com offer a large number of close-up lens selections. If, unfortunately, you could not find close-up lenses that fit directly to your camera, then try to buy step-up or step-down rings. They are quite cheap in the range of $5.00 - $15.00 depending on the size. The "Thread Size and Rings" page under the "Filters" section of my Nikon Coolpix 4500 user guide has all the necessary information. At worse, you can hand-hold the close-up lenses in front of your camera. As long as you will hold it firmly and the shutter speed is reasonably high, it should not be any problem.


Quote:
Originally Posted by Marble911
Another thing is, I've got no idea what the numbers usually mean with regard to the magnification of certain lenses (stupid beginner's question, I know)...if they give information at all (couldn't find info on the canon on I was thinking of).
Each close-up lens is associated with a number, its diopter. Normally, this number is one of th following: +1, +2, +3, +4, +7, +10, etc. It is define to be 1000/(focal-length-of-the-lens). Thus, a +4 diopter has focal length of 250mm=1000/4. The higher the diopter, the higher the magnification. The magnification is defined to be (camera-lens-focal-length)/(close-up-lens-focal-length). Thus, if your camera has a focal length of 32mm and if you intend to use a +4 diopter, the magnification is 32/250=0.128X. This means a real subject of 1" will appear on the image sensor as 0.128". Since the longer the camera lens' focal length, the higher the magnification with the same diopter. We could mount a 2X teleconverter on the camera and then a close-up lens on the teleconverter. Since the focal length of the camera is 2*32 = 64, the magnification becomes 64/250 = 0.256X. You can stack up to two close-up lenses together without losing image quality significantly. Thus, if I intend to use a +3 and a +4 close-up lenses, the combined diopter of this combo is approximately the sum of the two, 7=3+4. Therefore, the focal length of this combo is 1000/7 = 143mm. If this combo is mounted on a 2X teleconverter mentioned above, the magnification is 64/143=0.45, which is nearly as good as the macro mode offered by many cameras. Of course, if this case, the camera lens, the teleconverter, and the close-up lenses must be of good quality. Otherwise, image quality may be lower than you expect.

If you can afford another camera, Nikon's Coolpix 4500 is one of the best. Its price/performance is also good, especially after Nikon's $ rebate.

Hope this helps.

CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 user guide
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