Wanted: Sigma AF 400mm f/5.6 APO macro

In good working order please, fair price paid or may consider a trade for other Pentax items

There is one for sale now here in the Classified Adverts Forum

£350 so it seems!

I think John has investigated that one

The version he is/was looking for is the AF 400 APO Tele macro which:

a) is very good
b) quite rare

now probably investigating the 120-400 route.

Thanks for the heads up, I'm currently thinking about the new 120-400 with OS, released today apparently, it also has HSM of course. Sounds very nice, I wish someone would review one soon. SRS has listed one on the Bay @ £615

Regards,

John

John,

Do you think that Sigma 400 would be better than your signature's DA* 300 + 1.4 Tamron or 1.5 Kenko combination (by the way, can you confirm that they've actually both got the same magnifying factor, that is that they're both 1.5x)?
Also, is that Pz-AF 1.7x SHQ you have a Kenko too? I've never heard of that one, I do have the Promaster one though. Does yours AF with SDM lenses?

The Sigma 400 prime? probably better at the edge of frame not sure about the centre, the DA*300 + 1.5x seems reasonably good to me. The kingfisher was 100% crop from the centre. The thing is I'd lose SDM and quick shift with the old APO Tele Macro The new Sigma 120-400 OS HSM is very interesting, but I doubt the optical quality matches the prime (could be wrong, it's a much newer design) but I'd get OS to replace ineffective SR and keep HSM with full time manual focus
All the TC's I have are probably made by Teleplus in reality, the Tamron 1.4x does show less magnification than the Teleplus 1.5x, I've tested all 3 TC's. The 1.7x is also a teleplus and labeled such, the 1.5 says Teleplus (Kenko). All the TC's work with SDM but hunt a little, sorted with a tweak in quick shift, hope this helps.

John

If you don't mind, one question:

If one lens has a focus adjustment of +5, to use the lens with the Pentax F 1.7x AF TC the focus adjustment is the same, isn't needed or needs further adjustment?

And a similar question, what about a lens that need adjustment coupled with the tamron 1.4x (the one working with sdm)? It's needed to dial any focus adjustment ?

Thanks in advance

Hi

Not sure I understand the question. I've no focus adjustment set on the camera for the DA*300/4.

John

Sometimes a lens needs + or - focus adjustment on camera (k20 and k7) to focus razor sharp on subject.

For instance, my lens needs +5 on k7 for razor sharp images

My question is what happens to focus adjustment if the lens is coupled with a teleconverter ? Is still needed ?, will have to be adjusted ? or is not going to be needed ?

(completely offtopic :blush

I think you would have to check the focus adjustment again. Any TC has its own optics that could affect the settings compared to a lens on its own

Hi

I never needed any focus adjustment with the DA*300 on my K20D, at least I've never set any. The only lens I might be tempted to adjust would be the FA 50/1.4, as for adjustment with the TC, I think it would be difficult due to the minimum focus distance required.

John