Is this true?
"Focusing at infinity causes the nearest acceptably sharp objects to correspond with the hyperfocal distance."
Sorry for amateur question.
Is this true?
"Focusing at infinity causes the nearest acceptably sharp objects to correspond with the hyperfocal distance."
Sorry for amateur question.
Last edited by Jmarmck; 17-Dec-2014 at 09:57.
Regards
Marty
Its sort of the other way 'round. Focusing at the hyperfocal distance makes everything from half the hyperfocal distance to infinity acceptably sharp.
The key here is "acceptably sharp." This depends on the photographer's preferences and on how much the negative is to be enlarged to make the final print.
I was wondering if this was a method for finding the hyperfocal point. So for maximum sharpness the focus point should be hyperfocal point + 1 (whatever the units of measure is). Right?
Regards
Marty
Focusing at infinity causes the farthest away objects to be rendered as sharp as possible. Try it you may like it. Since those far-away objects will be the smallest and hardest to identify, maximum resolution is good. Closer objects will be progressively blurrier, but can still be identified due to their progressively larger size.
If there is no important part of the scene in the distance, the focusing method of Hansma works well. In my experience, the pre-printed hyperfocal charts work well only with contact printing. Since I enlarge my negatives, I can't follow the numbers in those charts.
Further discussion on the subject is here:
http://www.largeformatphotography.in...ocal-vs-Hansma
I will add that having made hyperfocal calculations in some circumstances, I was surprised to find that the images were in fact, not as sharp as I expected. I think it was some Rodenstock device I was using.
My experience was that the device's conclusions were just a little bit off. So now I still focus a third of the way in and close down to get full depth of field. It works for me.
Lenny
EigerStudios
Museum Quality Drum Scanning and Printing
After reading the posts on Hamsa and a bit on diffraction, I can see that hyper focusing nor the Hamsa method is a cure all. As noted in some of the posts about Hamsa it really is best to use infinity with scenic shots and watch the foreground. If the later becomes an issue then use some degree of hyper focusing may be necessary if diffraction becomes an issue. For close or macro work I have been focusing on some point and checking DOF for coverage. If the apertures get too small then a decision has to be made.
Thanks folks.
Regards
Marty
Yes, it's true. However, determining the hyperfocal distance and acceptable sharpness is complex. There are charts, computer programs, DOF scales, and other solutions. Unfortunately, they are all based on what someone else considers acceptable sharpness. As for hyperfocal distance, for fairly sharp prints it might be about 2000 times the apparent diameter of the lens' iris as viewed through the front elements. That figure of 2000 can vary widely, depending on final image size, subject matter, and most of all, photographer's definition of sharpness. Most charts, computer programs, and DOF scales are optimistic. If you want to study the subject of DOF in depth, go to http://www.trenholm.org/hmmerk/HMArtls.html and follow those links.
Jim, I just checked my DoF calculator (mine = I wrote it). It strongly disagrees with you. You can download it from http://1drv.ms/1Ai54SN . Please show me yours.
I wrote that spreadsheet for a discussion here with Helen Bach, whom I salute in passing. She and I were having trouble communicating so I gave her my arithmetic.
This is why they put a ground glass on cameras.
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