Out in the real world

[Grumpy John]

Following on from the Sigma USB Dock thread I ventured outside with the newly calibrated Sigma 17-70 lens. Just a few random images from the front of the house.
These are screenshots from DPP (the imaging software from Canon) which shows the point of focus (the little red square). The first of each of these images is the full image i.e. not cropped. These are all SOC no PP at all.

#1 Focal length 17mm, f2.8, 1/2500, ISO100


Same image at %100.


#2 Focal length 17mm, f2.8, 1/2000, ISO100


Same image at %100.


#3 Focal length 70mm, f4.0, 1/000, ISO100.


Same image at %100.


#4 Focal length 21mm, f3.2, 1/1250, ISO100.


Same image at %100.


#5 Focal length 70mm, f4.0, 1/640, ISO100.


Same image at %100.


#6 Focal length 70mm, f4.0, 1/640, ISO100. A challenging subject for autofocus as there is not much tonal variation.


Same image at %100. Looks a bit soft to me.

[Ozzie_Traveller]

G'day GJ

From your title I was expecting 'lockdown' stuff - and you surprise me again
These images appear to be 100% spot on for accuracy ~ I presume you also are happy with the results

I do like your selection of subject as well ~ the brick wall fading away seems an excellent choice ..... in the past I have used a newspaper sheet on the wall, shot from 45deg sideways, but your wall seems a better arrangement

Phil

[Grumpy John]

Thanks for looking Phil. My wife says that I'm full of surprises, not all of them good . I don't know if you read through the USB dock thread, but adjusting the lens for the infinity distance proved a PITA. I am thinking of placing a reflective house number on a star picket and driving it in to the ground and using the surrounding grass to gauge focus accuracy.
Yes, I'm pretty happy with the results.

[Ozzie_Traveller]

a) no - not following the related thread
b) focus =at= infinity is not a critical issue as at that distance, subject is small in size. It's more important that focus be 100% accurate closer to the camera
Phil

[Grumpy John]

Couldn't agree more Phil, maybe on a looooong lens it could be an issue.

[Isac]

As above John. Good results.