10/20
 

Hi any other suggestions to using sigma 10/20 lens for mainly buildings and architecture etc regards john

John, this lens gives some pretty crazy effects if you tilt it relative to the subject, which you may or may not want. If you want things straight, be very careful with your alignment to the subject. It has to be dead square on if you want to avoid distortion.

10/20
 

Many thanks for reply my ef-s 1785 is us m does crazy aswell am i better stick with it and using photo shop to correct regards john

Ducan's advice is true for all wide angle lens. Trapezoid distortion (perspective/tilt) is easy to correct for in Photoshop etc. Pincushion and Barrel Distortion is not so easy especial when mixed with trapezoid.

It appears the the 17-85 is know for it's heavy Barrel distortion at the wide end.

http://www.photozone.de/canon-eos/17...review?start=1

The 10-20 does exhibit some barrel at the 10mm end but looks pretty good from 14mm upwards.

http://www.photozone.de/canon-eos/30...review?start=1

I have the 10-20 and I can't say that barrel distortion has been a problem when photographing buildings compared to using the 18-55mm kit lens at the wide end. The kit lens seemed to introduce a S-shaped bow which meant you could not get all the horizontal and verticals straight.

The only way to sort these Barrel and Pincushion problems in software is to obtain or create a profile of errors for your model of lens. Then it becomes a simple matter to correct the tilt.

10/20
 

Hi ROB many thanks for your reply both comments very helpfull regards john

Do you mean you want suggestions for lenses that are better for architecture shots than the Sigma 10-20mm?
If so, perhaps the Tamron SP 17mm f3.5 or the Tokina 17mm f3.5 RMC?

Not very wide angle if on a crop factor body.

Did he say he had a crop sensor DSLR?

No he did not but he did not say he had full frame either. Please note my post did have that little word "if" in it! As most people have crop factor and according to the Sigma web site both the available Sigma 10-20's are only made in the crop factor fitting mount (DC) then I think it is reasonable for me to assume that he probably has a crop factor camera!