yoms

yoms

Lives in France France
Joined on Nov 28, 2010

Comments

Total: 4, showing: 1 – 4
On Sigma 50mm F1.4 DG HSM | Art Lab Test Review preview (548 comments in total)
In reply to:

yoms: Hi!
Can someone explain me something about the 3 shots of the distant clock to point out focus inaccuracy?

As the clock is really distant, I guess focus is set on infinity, right ? Moreover, focusing and exposure is always measured the aperture fully open, that is 1.4. So why is there misfocusing? Infinity is infinity, no ? There's no infinity + a little front focus or back focus.

Thanks for explaining.

Thanks again ! This really helps.

I wrongly thought that if there was so small an angle between infinity and the 3m marked distance, it was because there was almost no room for change when travelling from 3m to infinity. I understood something like : "Beyond 3m or so, it's (almost) the same. So why bother having a long distance scale in that range, it won't help/improve things".

So I understand that there's obviously a design choice by Sigma to optimize the focus ring travel distance from 1.7 to 3m. Should be the range they expect people to use the lens most and/or where the slightest change has the biggest impact. So it's the range where there's the most part of the focus distance...

Put that way, it makes sense. Ideally the mechanical travel distance should be infinite too as there is but one 100% perfect focus plan...

Thanks again!

Direct link | Posted on May 31, 2014 at 10:31 UTC
On Sigma 50mm F1.4 DG HSM | Art Lab Test Review preview (548 comments in total)
In reply to:

yoms: Hi!
Can someone explain me something about the 3 shots of the distant clock to point out focus inaccuracy?

As the clock is really distant, I guess focus is set on infinity, right ? Moreover, focusing and exposure is always measured the aperture fully open, that is 1.4. So why is there misfocusing? Infinity is infinity, no ? There's no infinity + a little front focus or back focus.

Thanks for explaining.

Thank you Andy. I understand that. I must have expressed myself badly...
What I meant is that it seems the clock is so far away that it's way beyond the hyperfocal distance (93.1m @50mm f/1.4 on APS-C). So what I don't get is : if the camera front-focused a little, it should still be within the "sharp focus range". No ? Unless the camera front-focused a lot.

Sorry for bothering...

Direct link | Posted on May 30, 2014 at 11:45 UTC
On Sigma 50mm F1.4 DG HSM | Art Lab Test Review preview (548 comments in total)

Hi!
Can someone explain me something about the 3 shots of the distant clock to point out focus inaccuracy?

As the clock is really distant, I guess focus is set on infinity, right ? Moreover, focusing and exposure is always measured the aperture fully open, that is 1.4. So why is there misfocusing? Infinity is infinity, no ? There's no infinity + a little front focus or back focus.

Thanks for explaining.

Direct link | Posted on May 30, 2014 at 10:08 UTC as 34th comment | 4 replies
On Lightroom Photo Import article (117 comments in total)

Many thanks Martin ! You've just answered one big question : how can I put the newly imported photos apart from the processed ones ? The idea of creating a folder named "Import photos" is great. I love the "Previous import" collection in LR to get back to my previous import. Sadly, I often make several imports at the same time that I consider as 1 unique import. But your idea solves this issue by keeping all these photos in one place until I decide to move them to their final destination.

Cheers,

Direct link | Posted on Aug 25, 2012 at 19:24 UTC as 9th comment
Total: 4, showing: 1 – 4