17-35mm G version or 16-35mm Carl Zeiss

[classiccameras]

David,
Would disabling the first curtain shutter on my A37 also apply to the Tamron 17-50 or is it just for the old KM lenses for the reasons you explained?
Thanks
Pete

[bfitzgerald]

I've used the electronic first curtain on the A57 and not noted any problems so far (with any Minolta or Tamron leness) that's "so far"
I know what the user manual says (the recommend not using it for KM lenses), but many of the Sony lenses are Minolta lenses (well some are)

Maybe if you are stopping down a lot it might cause a problem, but real world I've yet to see it. I can't test right now as the A57 is away for repair.

I have shot the 24-85mm on 35mm and noted the same soft focus effect at the telephoto end (I had the RS version). I believe this is due to "Spherical aberration"
It is def notable on that lens, but not as severe as the Pentax 18-55mm which has very serious issues with this above 35mm (basically unusable until stopped right down)

As I wanted a "bit more speed" at the tele end I decided to sell the 24-85mm. It's quite good at the wide end though, but if you already cover the wide angles with a 17-35mm or something like that, I'm not sure how useful the 24-85mm is bearing in mind that limitation. For a normal lens you might be ok with a 28- something, beefing up the UWA's with a zoom like above..I'd possibly add a few primes in there like a 24mm maybe.

I believe the 24-105mm has a couple of aspherical elements, that might explain why I've not see that issue on that lens (though as DK say it has it's issues with distortion and CA)

[shooter]

[quote=I know what the user manual says (the recommend not using it for KM lenses), but many of the Sony lenses are Minolta lenses (well some are)[/quote]

yes but Minolta lenses aren't KM lenses or am I missing your point

[classiccameras]

Thanks Barry, I do know that the KM 17-35 is a re badged Tamron for KM. Both examples get good reviews. I have recently seen a Minolta 24-50 Constant F4 in my local shop, they say its quite a rare lens and it gets very good reviews in dyxum and Mhoner sites.

Its a nice thought to have one lens such as a 24-105 to cover a lot of your photographic work and reduces the number of lens changes, but I think there are big compromises on optical performance compared to the shorter zooms.

I would rather have 3 good performing lenses as against one mediocre zoom

[bfitzgerald]

You are probably right I do not currently have a 24-105mm nor am I sure that I will get one either but I've tried a few and I think for APS-C users it's a better bet than the 24-85mm. I've quite a few full frame lenses and the Tamron 17-35mm version (which I got off a member on this site) I have good coverage over a wide focal range bar longer tele lenses/fast ones. I usually avoid big zoom lenses for the reason you mention compromises. Saying that I was never a fan of the Sony 16-105mm which I feel has more issues than a 24-105mm. Depends where you are going with this, I'd be more interested in the tele end for such lenses.

There are quite a few ways to build a system even on APS-C, eventually I expect to go full frame but not for a while. So I would tend to avoid too many APS-C lenses.
I've not used the 24-50mm so can't say how that stacks up I've heard it's decent enough.

[Greg Beetham]

I have a KM24-105 and it’s quite ok on APS-C, (with caution) not many distortions apparent, it does nice work close up and seems to produce a reasonably flat field even wide open, I always use it at around f8 for copying some text or such and is surprisingly good for its size and weight, but it does suffer a little from fogging if you shoot against the light in backlit (windows in the background) situations, so you always have to remember to shoot with the light where possible not against it, and it doesn’t like light actually falling on to the front element either, then you will get flare/diffraction/diffusion/fringing/ca type effects.
But I still like it anyway, because it’s small and light and surprisingly sharp, (especially in close) you just have to be mindful of its limitations.
I definitely wouldn’t buy it with a view to using it on FF at some future time, the barrel distortion at 24mm is something to behold on FF; DK used one on the A900 at the time when that camera came out, he posted a photo illustrating the problem; it’s hardly there on APS-C, (it still has some residual BD, but correctable with minimal effort).
Greg