I confirm Andy's suggestion that the circle of confusion diameter may be off for some calculations on high res sensors. AFAIK, the expensive top of the line Sony lenses are sharp enough for the new sensors, the Zeiss formulated glass can be better still, ditto for Sigma Art series. The old saw about 1-2 stops in from max and a few in from the minimum still holds( ie for a 1.4 lens, sharpest will be 2/2.8 thru 5.6)
-Lew Schwartz
On Thu, Nov 17, 2022 at 5:58 PM Andrew Davidhazy <andpph@xxxxxxx> wrote:
Kostas, depth of field given a particular focal length and aperture should be the same ... unless the basis for the determination is different. Like acceptable circle of confusion.
Andy
________________________________________
From: PhotoForum <photoforum-bounces@xxxxxxxxxxxxx> on behalf of Kostas Papakotas <clenchedteethphotography@xxxxxxxx>
Sent: Monday, November 14, 2022 5:27 PM
To: PhotoForum educational network
Subject: Wide Zoom lens question
hi members!
I would like to get your impressions & experiences regarding a Wide Zoom lens I intend on buying.
it is the Sigma 17-35 mm F2.8-F4.0 EX Lens.
Some time ago I bought a similar Pentax model, the Pentax-FA J 18-35mm F4-5.6.
which proved to be unacceptable regarding the expected large depth of field (by starting at F/4)
Thing is the FA J has stolen monetary resources I could have used to buy a single better lens all together.
Now I will have to settle for the Sigma one.
What do you think?
Links
https://www.pentaxforums.com/userreviews/sigma-17-35mm-f28-4-ex-aspherical.html
DG Version
https://www.imaging-resource.com/lenses/sigma/17-35mm-f2.8-4-ex-dg-aspherical-hsm/review/
https://www.dpreview.com/articles/8643959634/sigma1735mm
