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11-15-2009, 10:19 AM   #1
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645 Ignorant

I lurk some over here and have four very nice 645 lenses I use (and love!) on my K20D. The prospect of a 645 Digital is exciting to me, since I was never a film shooter and know nothing of film usage.
Will my 645 lenses (A&FA) work properly on the new digital 645? If so, I will start buying more, they are such fine quality lenses, I often just hold them and appreciate the craftsmanship.
Regards
Rupert
One with the 645 120 Macro on my K20D


11-15-2009, 12:26 PM   #2
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And do you think that lens would produce anything different than a 35mm SMC Pentax-FA 100mm ƒ2.8 Macro on that camera?
11-15-2009, 12:52 PM   #3
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Most likely not, but I only paid $125 for this lens, what did you pay for the 35mm? Did you have an answer to my question?
There are many great lenses, in all formats, but I am interested in the 645 Digital, not because I am good, but because I am assuming it will be. Meanwhile, my K20D is very worthy of all that I currently shoot.
Regards!
Rupert
11-15-2009, 01:23 PM   #4
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QuoteOriginally posted by Rupert Quote
Will my 645 lenses (A&FA) work properly on the new digital 645? If so, I will start buying more, they are such fine quality lenses, I often just hold them and appreciate the craftsmanship.
Technically they will work, in that the lens mount will be the same. But Pentax will be releasing digitally-optimised lenses that will perhaps image better. Also note that the 645D is misnamed, in that it will have a smaller sensor than the 645 format.

I collected available information in the article Pentax 645 Digital On The Horizon.

11-15-2009, 03:54 PM   #5
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Thanks, nice link and I appreciate the information! If it is under $10K I might end up with one, if not, I hope you do and come back to show us what you can do!
Thanks&Regards
Rupert
11-15-2009, 09:46 PM   #6
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That's a good price. I paid much more that the 100mm FA ƒ2.8 Macro. But I have put my 67 SMC Pentax 105mm ƒ2.4 and 67 SMC Pentax-M* 300mm ƒ4 ED (IF) lenses on my K-7 and compared the results with my 35mm SMC Pentax FA 100mm ƒ2.8 and 35mm SMC Pentax-A* 300mm ƒ4 and could not tell the difference in quality. I was just wondering what the big craze is for mounting MF lenses on digital cameras is all about.
11-15-2009, 10:10 PM   #7
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Tuco, my original reason was to force myself to learn to use my camera better by an all manual operation, since I am not an experienced shooter like many film shooters are. Then I found th equality of th elens construction on th e645 lenses to be superb, and the IQ to be equal to my DA lenses, so I kept buying them. I don't use them too often, but I enjoy it every time I do, and it has helped me better understand exposure and getting the settings right.
Regards
Rupert
One more from the K20D + 645 120Macro
11-15-2009, 10:17 PM   #8
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To answer your question, Rupert, I think you will be able to use any of the Pentax 645 A or FA lenses on the 645D, as well as the 67 lenses with the adapter, so I think you should feel free to collect them. I also think they will work particularly well with the smaller digital sensor, as the image circle of these lenses will be somewhat larger than that of the sensor, thus reducing aberrations or vignetting present in these lenses when mounted on the 645 or 67 film cameras.

Nice photo and nice flower. But I would have to add that the quality of a flower photo has more to do with the subject, composition and lighting than whether you used the Voigtlander 125/2.5, the Zeiss 100/2, the Pentax 100/2.8, the 645 120/4 or the 67 100/4. But I take your point about the $125 cost…a lovely lens for such little money.

As to whether one should wait for “digitally optimized” lenses, I doubt whether any will be released any time soon for the 645D. If anything, we may see the currently discontinued 645 FA’s go back into a production run to coincide with the release of the 645D, but I wouldn’t expect anything more. And there may not be any advantage in such optimisation. Digital optimization essentially refers to the following enhancements: 1) the addition of lens coating on interior lens elements to reduce the internal reflections originating from the sensor being reflected by lens elements back onto the sensor, causing reduced contrast; and 2) a redesign of exit elements so that light is more vertically incident onto the sensor, thus avoiding shadowing on sensor elements located at the bottom of sensor well structures, leading to vignetting, and refraction at the top of these well structures, resulting in increased chromatic aberration.

Existing Pentax lens multicoating is already arguably the best offered, and the flange to register depth of 645 and 67 lenses is already very large (75mm or 84mm) when compared to that of 35mm cameras (45mm for the Nikon F-mount), so that when these MF lenses are used on the reduced sized digital sensors (APC, 35mm or the new 645D MF), the light incidence on these sensors is likely more vertical than that for any “digitally” redesigned native APC or 35mm lens.

Regards, Alan


Last edited by ARCASIA; 11-15-2009 at 10:22 PM.
11-16-2009, 08:02 AM   #9
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Thanks for the additional information Alan, very interesting. I am very interested in the new 645, and look forward to the introduction. I already know I don't "need" it, but I have few money grabbing vices, so I might indulge my greed for this body.
Regards!
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