MicrostockGroup
Microstock Photography Forum - General => General Photography Discussion => Topic started by: old crow on May 29, 2013, 08:55
-
Good Morning,
I would like to ask if DOF calculators are accurate enough for stock images? is there a rule of thumb by which you reduce the calculators measurement to insure the images in focus acceptance?
Thanks to all who help.
-
The rule of thumb is to not use a DOF calculator, especially when shooting digital - you can check your DOF by zooming your images. Never used a DOF calculator, never needed one.
-
I never found calculators applicable.
Considering that DOF is an artefact and no matter what aperture you use the image is only sharp where focus is placed.
However, there are many illusions that add to the experience of sharpness, and dof is one.
The most important (DOF determining) factor is the size of the picture. Are we at 1:1 or have we scaled down. If you downscale enough your can get dof to stretch: Eg. make the illusion of sharpness reach further into the picture.
-
I use a DOF calculator as an educational tool; it helps me to previsualize how a set of shots may turn out. And I've used it after the fact to understand the result I got. It's also useful when shooting landscapes to maximize the area of sharpness by focusing at the hyperfocal distance instead of on a particular part of the scene.
I spent some time at the Desert Museum near Tucson a couple of weeks ago. I shot hummingbirds at chose range with my lens wide open. The results were instructive, but if I'd used a DOF calculator before shooting I'd have known just how much I was pushing the envelope. As it was I had 1.1" of maximum sharpness. Good thing hummingbirds are so small!
-
I think the best thing here is to learn the theory (1/3 of DOF is in front of the focal point and 2/3 behind) and always know what aperture you are using (Aperture priority or Manual mode. Soon you will learn what aperture to use and where to focus to get sufficient sharpness.
-
Thanks all,
It always seems to be a struggle, lens vs object vs DOF. The DOF preview is pretty dark usually on the 800. I guess I need more elephants and buildings in my area. I guess that is why someone invented stack focus.
-
Understanding how to use DoF is very important, particularly for landscapes, and the markings on the old lenses are actually very useful (and are presumably the same as "DoF calculators", which I've never seen). Any chart or calculator will be way better than letting the lens focus at infinity and shooting away without thinking.
-
Using prime lenses also help. I usually use just three different lenses, I have learned their DOF at different apertures and distances. With zooms learning is more difficult because there are too many combinations to remember.
-
Understanding how to use DoF is very important, particularly for landscapes, and the markings on the old lenses are actually very useful (and are presumably the same as "DoF calculators", which I've never seen). Any chart or calculator will be way better than letting the lens focus at infinity and shooting away without thinking.
Agree. It is important to have an understanding of hyperfocal distance so you know what you want to achieve.