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-   -   lens format (https://forums.steves-digicams.com/general-discussion-11/lens-format-127663/)

kam213 Aug 18, 2007 12:29 AM

I need to use a 60mm lens thats made for a 2/3 ccd on a 1/3 ccd, would this allow less light to the ccd compared to a lens of the same focal length and aperture thats made for a 1/3. ???

granthagen Aug 18, 2007 1:53 AM

I can't say that I know the answer to this question, but why break tradition now?

By way of analogy, people have been using lenses designed for 35mm film cameras on less-than-full-frame DSLR sensors for quite some time, and the the main problem they seem to encounter sometimes is a slight drop-off in sharpness toward the edges of the frame. That's one reason why lens manufacturers started making so-called "digital lenses" that are designed for the smaller imaging area of the standard APS-C sized sensors. It could well be that you see something similar using a lens designed for a larger sensor than you are using it with. I doubt that you would see a reduction in the amount of light landing on your smaller sensor. If this answer is off base, I hope someone that knows better will point it out.

Grant

kam213 Aug 18, 2007 1:24 PM

I just thought the light would be less on the larger format lens because of it being spread out over a wider wider area.
but not sure.

VTphotog Aug 18, 2007 1:58 PM

If the aperture and shutter speed are the same, the exposure will be the same (for same ISO sensitivity).

style="BACKGROUND-COLOR: #000000"GRANT: Lenses designed for 35mm don't generally have a problem on APS size cameras with light fall-off. The opposite is the case, as the light circle of the designed for digital lenses is smaller, and will vignette on full frame 35mm. The real advantage is in the smaller size and weight. The lens coatings are also a bit different, to compensate for the more reflective surface of a digital sensor as opposed to film.

style="BACKGROUND-COLOR: #000000"brian

kam213 Aug 18, 2007 2:18 PM

I meant would the light intensity on the ccdfrom the larger format lens be less than a 1/3 lens ?

VTphotog Aug 19, 2007 12:46 AM

No.





granthagen Aug 19, 2007 12:55 AM

Two "no's" going once...twice....

Grant


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