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05-18-2010, 05:19 PM   #76
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QuoteOriginally posted by newarts Quote
The combination of a 300mm lens reversed in front of a 300mm lens will have a magnification of 1:1 and a working distance equal to the registration distance.
I stand corrected. You're right.

05-18-2010, 08:42 PM   #77
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I think I am understanding what you are asking now. Since the original photo was 4672 pixels wide and covered 2.5mm, the pixel size was 0.53 um. When I uploaded the original file to flickr, the site resized the photo and did not keep a copy of the original size. I am sorry to say that I don't have the original.


QuoteOriginally posted by falconeye Quote
I wondered if you would understand what I mean.

A pixel with a K20D/K-7 displays 5m at 1:1 and 0.5m at 10:1.

However, if you're downscaling to 1024 for the web, this becomes 23m and 2.3m resp.

You may still call it 10:1 but it is meaningless. A 3x2px photo at 10:1 would have 0.8mm wide pixels and stll you would call it 10:1 ...
05-18-2010, 10:05 PM   #78
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QuoteOriginally posted by glasbak Quote
It is still a wide angle, with the same focal length, but normally it projects the huge world onto a small sensor, exchange world and sensor, then it projects a sensor sized part of the world onto a huge image circle.
I think at this point we're quibbling over what it means for it to be a wide angle lens. Something that takes creates an image with a small FOV is pretty much by definition not wide angle as far as I'm concerned.
05-19-2010, 12:23 PM   #79
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I think best an easyest is combining rings with TCs.

If you have 50mm macro, 50mm of rings plus a 2x TC gives you scale 4:1. With a 90mm macro it has to be 90mm of extension plus the TC

The rings have to go between lens and TC.

I have used this sort of combination and the results are good. You will need an adecuate flash system. I am using 2 360 fgz mounted above and below, to a side, with home-made bar, using wireless sync of K10D.

Cheers - Klaus


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