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Forum: Lens Clubs
10-09-2010, 11:40 AM
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hmmm...looks like could be slightly below half a stop. though it may seem that the general consensus is that both lenses are made by Cosina, it maybe perhaps possible that the Revuenon and Porst don't have the same light gathering capability by virtue of coating of slight variation in lens construction perhaps?
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Forum: Lens Clubs
10-08-2010, 01:43 PM
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actually the test is about knowing the exact exposure equivalence on the image rendered. or in other words, exposing the image with the same brightness level to that of the other lens. one may or may not see the difference in exposure by looking at the compared image, but the question is, by how much?
to be more precise, the 2 lenses are set at their individual wide openings, e.g. 1.2 and 1.4. then setting the ISO level at constant ISO 100. then after, one must adjust the shutterspeed of the 1.4 at a certain point that the image would look just the same brightness of that of the 1.2. if you said that 1/40 would still show that the 1.2 is brighter, then try adjusting it further to 1/30 or 1/25 and see if both images brightness balanced out. if it does, then the half-stop advantage is thus accurate. if it's get over well below 1/25, let's say 1/20, then the better the 1.2 is.
another way of doing it is doing the opposite. set both lenses aperture openings at wide open and keep both shutter speed constant at 200, then adjust the ISO by how much exposure is needed to balance out both images.
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Forum: Lens Clubs
10-08-2010, 10:33 AM
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1/6 is not too much of a difference nor significant enough. but anyway, is the Cosina, the same as the Porst?
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Forum: Lens Clubs
10-02-2010, 09:52 AM
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this would be interesting to compare and look at. Blende, could you also post some images that would show the distinctive OOF rendering of both lenses on different subjects?
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Forum: Lens Clubs
10-01-2010, 03:34 PM
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are you going to sell it?
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Forum: Lens Clubs
10-01-2010, 12:49 PM
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wait a min....I thought you were part of the group that find no sense on having an f1.2? :D
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Forum: Lens Clubs
02-07-2010, 09:24 PM
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it looks like a dud. I think you should send the lens to me inorder to see if it works any better. :D
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Forum: Lens Clubs
01-13-2010, 11:33 PM
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Grouco, the question you need to ask is, is there something you don't know about bidders?
there are both scammers in both sides of the fence, just be careful. don't want any of that crap about the buyer never received the item or item wasn't as described. just a caution.
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Forum: Lens Clubs
01-13-2010, 11:18 PM
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so you're the guy that was selling that lens. shame...shame.....shame on you. just kidding ! :lol::lol::lol:
no offense intended but the bidding did looked suspicious. just stating from experience. :cool:
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