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發表於 2014-11-19 04:39:41
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本帖最後由 18x24 於 2014-11-21 04:42 編輯
bubu 發表於 2014-11-18 07:09
These days, I am rather tempted to convert an A7 to do color IR photography.
Re Jason's post in ano ...
The choice of which IR pass thru' wave length depends on what application/result would you like.
Since the Leica IR filters I have allow some red to pass thru', i.e. have certain kind of red on color IR, I believe they are not IR 720.
They probably between 590 ~ 680, my guess. If you just want BW IR, then IR 720 is fine. For color & BW IR, you may need 590 ~ 680.
Ask "lifepixel.com" for details. They should know. The larger the number, the less red will pass thru' & tends to less IR color effects.
My two cents:
About the A7, if you plan to use M lenses, my concern is: you may not get good results on wide angles - especially wider than 35mm, due to vignette.
I have tried even 35mm & Leica IR filter with A7R, though without modification, due to heavy light loses at the corners.
So far, I am pretty comfortable with M8/8.2 for IR photography without any modifications.
I plan to try on the medium format as well with a back that the standard IR cut filter can be easily replaced with an IR pass thru' filter, i.e. can try difference IR wave length. Will see.
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發表於 2014-11-14 09:09:25
