DOF calculators in the digital world are total nonsense. After ruining a good few digital images with them in the early digital days, the only way to get accurate \'digital\' DOF charts was to start all over again, ignore the distance scales on the lenses, make my own scales and test the lenses myself and examine the results at 100% in RAW.
Quote Canon\'s new DOF calculator - \"To create a constant certain assumptions are made. These assumptions are that the eyesight of the viewer is able to determine resolution of around five line pairs per millimetre, it is viewed from around 25cm and the viewing size is approximately a 10x8inch print.\"
Yet again we are left by pioneers of digital technology with this age old bunkum.... how about a total revision of the whole entire situation, somebody PLEASE!!!! The time has come (seeing as 99% of the camera world is shooting digitally) to revise and recreate hyperfocal distance ledgers on all new lenses so we can just stop all this garbage
Stick on Scales - All my lenses are tested inside out hyperfocally. I have to make all my own stick on \'scales\' , increments that ignore all the totally inaccurate metres and feet values values these scales spit out. How on earth can I set my 17-40 lens to 2.36m anyway?! The scale is so bad I can\'t even set it without guessing....
Nikon are you listening too?!- Nikon are just as bad. The 14-24 has such a deeply recessed focus scale that you can actually get parallax errors between the plastic window\'s zero point and the scale beneath! Come on. Even if the scales were 100% accurate I would get it wrong if my line of sight was slightly to the left or right.
High Resolution - A high resolution 21mp image losing focus at infinity can be so utterly fine it can\'t even be seen that clearly with 10x LIVE VIEW on wide angle lenses with the DOF preview pressed.(far easier on telephotos mind you) It has to be examined in RAW by looking at the centre and corners of the lens.
Field Curvature Issues - As some lenses have a curved image plane the centre of the image will be in focus and the edges will be slightly out of focus. Again the calculators do not allow for this phonomena either.
But well we dont care do we, as long as its there abouts. I dont care as long as my failing eyes can see a print from 25cm in focus. Tell that to a picture editor. It drives me around the bend that all camera manufacturers still wont address this situation. But then where is my mirror lock up button?! haha
Jul 31, 2009 at 04:14 AM
Previous versions of David Clapp's message #7364873 « More DOF Calculator b*llsh#t »
I dont care as long as my failing eyes can see a print from 25cm in focus. Tell that to a picture editor. It drives me around the bend that all camera manufacturers still wont address this situation. But then where is my mirror lock up button?! haha