Diaphragm Blades
Posted 18/12/2009 - 23:47
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Don't forget they need to be an uneven number so that you get a star with double the legs.
18 is certainly a lot, John do you perhaps know how which lens has the most blades?
18 is certainly a lot, John do you perhaps know how which lens has the most blades?
Stefan
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Posted 19/12/2009 - 00:06
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Lenses of the same era as the one I described do tend to have a lot of blades.
I would suspect that the SLR lens with auto diaphragm led to fewer, thinner blades to increase the speed of stop down.
I don't know which lens had the most blades.
I would suspect that the SLR lens with auto diaphragm led to fewer, thinner blades to increase the speed of stop down.
I don't know which lens had the most blades.
Best regards, John
Posted 19/12/2009 - 00:21
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My old (early 20th century) Kodak 3A Folding (122 film format) has 11 blades.
Yves (another one of those crazy Canucks)
Posted 19/12/2009 - 00:34
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I sold a Pentacon 135mm f2.8 on eBay recently that had 15 blades.
Tim
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27”, Macbook Pro 17”, iPad, iPhone 3G
Flickr • Fluidr • PPG • Street • Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!
AF - Pentax K5, Sigma 10-20/4-5.6, Tamron 17-50/2.8, Sigma 30/1.4, Sigma 70-200/2.8, Tamron 70-300/4-5.6
MF - Vivitar CF 28/2.8, Tamron AD2 90/2.5, MTO 1000/11
Stuff - Metz 58 AF1, Cactus v4, Nikon SB24, Raynox 150, Sigma 1.4x TC, Sigma 2x TC, Kenko 2x macro TC, Redsnapper 283 tripod, iMac 27”, Macbook Pro 17”, iPad, iPhone 3G
Flickr • Fluidr • PPG • Street • Portfolio site
Feel free to edit any of my posted photos! If I post a photo for critique, I want brutal honesty. If you don't like it, please say so and tell me why!
Posted 19/12/2009 - 14:10
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johnriley wrote:
I was given a very old lens today, a Goerz Anastigmat Celor 150mm f4.8, and thew diaphragm has a staggering 18 or more blades. They don't make them like this any more! No coating though....
Tried it on the K20 yet? Any pics to show?
I was given a very old lens today, a Goerz Anastigmat Celor 150mm f4.8, and thew diaphragm has a staggering 18 or more blades. They don't make them like this any more! No coating though....
Joining the Q
Posted 19/12/2009 - 14:25
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Quote:
Tried it on the K20 yet? Any pics to show?
No, it might be better than my Pentax lenses and then I'd be very upset....Tried it on the K20 yet? Any pics to show?
Although it would be possible to use it on bellows on the K20D. There's no focusing mount so it would have very resticted use. We'll see how it does on eBay after Christmas.
Posted 19/12/2009 - 14:32
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Some of those old brass lenses are incredibly sharp (I've tried a couple out on mine) but the contrast tends to be very low. Plus having to cart the bellows around just to focus is certainly a pain 'tis true...
Joining the Q
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24430 posts
24 years
Tyldesley,
Manchester
I was given a very old lens today, a Goerz Anastigmat Celor 150mm f4.8, and thew diaphragm has a staggering 18 or more blades. They don't make them like this any more! No coating though....