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GH2 Are there any good parfocal zoom lenses for the Panasonic GH2?
- Thread starter rc444
- Start date
Canon FD mount has a 20-35 f3.5 and 35-105 f 3.5 that should be decent and sort of cheap. Combine with a focal reducer to get some light back and they should be pretty good. I finally have one of the 35-105 that I'll be able to use once I get it into service. I'd like a 20-35 too, but the price for those is pretty high right now.
joe12south
Veteran
Not native, but this is a good choice: http://www.sigmaphoto.com/17-50mm-f28-ex-dc-os-hsm
let us know how your 35-105 is - not sure if i got a bad one but not a big fan so far, pretty much unusable until stopped down a fair bit and the closest focusing distance is quite extreme compared with what im used to with modern zooms.
My sample is pretty sharp wide open. Overall a very useful lens, I like it a lot.
There definitely are not any native parfocal zooms, or at least not worth mention.
I'm on my second 35-105, the first I bought cheap figuring I could get inside and clean it, but an "ugly" grade parts lens to hopefully fix that. But recently got another in a set of lenses. I'll have to get that attached and checked, but the problem there is the cheap adapter which probably isn't going to have the proper flange distance so the parfocal will be off.
That said, both of the FD zooms listed have an adjustment for flange back focus, you can find it online through a search (I didn't store the address). So if you know your adapter is set correctly, and your FD zoom isn't parfocal, you probably need to do this adjustment.
As noted, there are faster zooms in different mounts that would be better (but cost more).
I'm on my second 35-105, the first I bought cheap figuring I could get inside and clean it, but an "ugly" grade parts lens to hopefully fix that. But recently got another in a set of lenses. I'll have to get that attached and checked, but the problem there is the cheap adapter which probably isn't going to have the proper flange distance so the parfocal will be off.
That said, both of the FD zooms listed have an adjustment for flange back focus, you can find it online through a search (I didn't store the address). So if you know your adapter is set correctly, and your FD zoom isn't parfocal, you probably need to do this adjustment.
As noted, there are faster zooms in different mounts that would be better (but cost more).
I'f you approach the situation carefully, you can get a fairly good parfocal effect with the Olympus 12-40 f2.8. it's not perfect but if you stop down to about f4 for close subjects and possibly open up for further subjects, it seems pretty good. It also depends on how much you zoom and whether you're in the short or long of the lens when zooming. It's not a true parfocal lens though. I've only had the 40-150 2.8 for a short while and haven't tried that yet. I know it's not a true parfocal but may be like the 12-40 and good enough to fake it if you don't need it too often or over too great a zoom range. I'll try to remember to try that this weekend and get back to you.
The biggest reason to need parfocal is to do a zoom in a shot.
The other way to accomplish this might be a video zoom lens in B4 mount. You'll typically need an extender to cover the EXT scan setting, but it might be what you need for a price you can afford. If possible go for the lenses that have the green ring around them, they were better quality meant to work with CCD. Without the green ring you could always moves each tube to get the beams focused, but the CCD's are glued to the prism, so no adjustment is possible.
The other way to accomplish this might be a video zoom lens in B4 mount. You'll typically need an extender to cover the EXT scan setting, but it might be what you need for a price you can afford. If possible go for the lenses that have the green ring around them, they were better quality meant to work with CCD. Without the green ring you could always moves each tube to get the beams focused, but the CCD's are glued to the prism, so no adjustment is possible.