quick question about gh2 crop factor and canon eng lens

D

dunpeal

Member
Hello,
I have a b4 lens to m4/3 adaptor and a canon eng lens with 2x. I noticed whenever i shoot images with it using my gh1 there is a softness and also vignetting. Does the crop factor on the gh2 eliminate this ?
 
It depends on the focal length of the lens and the diagonal it covers, 2/3",1/2"(if it is for 1/3" forget about it) etc so you might want to tell us the focal length. The GH2 crop factor will be the closest you will be to eliminating this problem but there are some compromises. Firstly, you will probably lose youre wide angle cause to get the 35mm equivalent you will need to multiply your lens's focal length by 5.2 (2x2.6=5.2) So a 12-50mm lens for example would become a 62mm-260mm. The other significant trade off is iso performance. when in ETC crop mode the noise is much higher and you don't want to go like above 800 or so. So you lose some low light.
 
In ETC 16:9 1080 mode the multiplying factor for a 2/3" lens is 4.8x (i.e. a 10mm become a 48mm instead of a 39mm when the same lens is mounted on a 2/3" chip camera). So you loose a slightly more than 20% at the wide end. So vignetting is unlikely to be a problem.
However, some users experienced a lot of softness, expecially with apertures from f1.7 down to f4.
 
Yes I have the same question. I put on my workplace's Canon ENG lens on my GH2 and it is fine when I flip on the 2x extender without ETC on; but very very soft between f1.7 to f3.5 when I turn on ETC.
So what ENG lens should I get to eliminate this problem?

Does C-mount lens have this problem too?
 
kyc said:
Yes I have the same question. I put on my workplace's Canon ENG lens on my GH2 and it is fine when I flip on the 2x extender without ETC on; but very very soft between f1.7 to f3.5 when I turn on ETC.
So what ENG lens should I get to eliminate this problem?

Does C-mount lens have this problem too?
Click to expand...

I'm afraid, but I think all eng lenses will suffer from this softness problem wide open. Those lenses are optimized to focus light rays through the beam splitter in front of 3 CCD chip camera.
Most of C-mount lenses are build to work with single sensor camera, so softness would be a non issue.
 
Thanks for the replies, i have a canon j14 2/3 lens. The reason i got it was so i can have a versatile lens that can zoom and go wide. It seems that i went with the wrong lens set.. C mount zoom may be better ?
 
Gaman said:
I'm afraid, but I think all eng lenses will suffer from this softness problem wide open. Those lenses are optimized to focus light rays through the beam splitter in front of 3 CCD chip camera.
Most of C-mount lenses are build to work with single sensor camera, so softness would be a non issue.
Click to expand...
So is a 2/3 ENG lens not as good for a GH2 or other single-chip cmaeras as a C mount zoom because of the beamsplitter thing? Can anyone else comment on this?
 
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