Just picked up a Sigma 35mm 1.4 for my 5Dc. What are your testing recommendations ?

Started Feb 9, 2014 | Discussions
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unicursalhexagram
unicursalhexagram New Member • Posts: 17
Just picked up a Sigma 35mm 1.4 for my 5Dc. What are your testing recommendations ?

Hey everyone,

I'm hoping to mine your collective consciousness for your tried and tested methods of testing third party lenses.

As its a Sigma there's always the possibility of the reverse engineered algorithm not getting it quite right all the time. So, whilst I'm still in the return period, I wanted to ask what your recommended ways of testing a lens for front/back/distance focus.

There's the method of putting it on a tripod, aiming it at an autofocus test chart like the one here : http://regex.info/blog/photo-tech/focus-chart but I was wondering if there's anything else e.g accepted ways of seeing how a 35mm lens performs for subjects at a distance and what is considered anomalous.

Also, given that there's a Sigma dock out for finetuning focus where could I read up about the methodology behind the fine tuning ? Is it just a case of playing around with settings at each distance scale setting or is there a nice summary somewhere that can explain the theory behind it ?

Many thanks in advance ! Looking forward to hearing your tips.

Igor

Canon EOS 5D
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Tyr-Sog
Tyr-Sog Contributing Member • Posts: 795
Re: Just picked up a Sigma 35mm 1.4 for my 5Dc. What are your testing recommendations ?

I'm not sure about methods, but mine is the sharpest lens I ever had even at f1.4.  I need no micro adjusts, focusing is spot on, etc.

Good luck!

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WryCuda
WryCuda Senior Member • Posts: 4,620
Re: Just picked up a Sigma 35mm 1.4 for my 5Dc. What are your testing recommendations ?
1

After you check for accuracy of focus, you could shoot some test charts at various f/numbers and check the resolution at the centre and edges.

Chart

I printed A4 size and set up a board with 5 charts; see my gallery.

Multiply best resolved number x300 to get LPPH. Compare with data from the following site.

http://www.photozone.de/

 WryCuda's gear list:WryCuda's gear list
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