What's a "focus screen" on a lens?
I'm just curious, but how to you see the hyperfocal distance without the focus screen on your lens?
xenith0 said:There are lots of smartphone apps and online calculators that can calculate hyperfocal distance. You could jot down a few distances for commonly used apertures and focal lengths to use as a cheat sheet if you don't have a phone handy, or bring a calculator and manually calculate out in the field
How about after calculating? For example:
Focal length of 22 and an aperture of 11, gives 1.94m(3.28 ft) how am I suppose to focus without the dof scale gauge?
There is a couple of ways around it.
I wrote about it here: http://darthbertz.blogspot.com/2010/07/getting-everything-into-focus.html
What if I do not have a distance scale on my lens, and/or I do not know whether I can focus at the exact spot?
Do not worry. Hyperfocal distance will work further away. So if you are not sure, just focus on a spot further away than the calculated hyperfocal distance, and everything from at least half of the distance of that spot to infinity will be in focus.
Example:
Using the same settings from the 1st example.
focal length=18 mm
aperture = F8
Camera = Nikon D5000 (CoC = 0.02)
Hyperfocal = 2.04m
Using the same settings I can still focus at 5m instead of 2.04m. Now everything from at least 2.5m (5m divide by 2) to infinity will be in focus.
I can also focus at 10m instead of 5m or 2.04m. If I do that, everything from at least 5m to infinity will be in focus.
However, if I focus at 1.5m (which is less than the hyperfocal distance), it will not work... So focused distance has to be greater than the hyperfocal distance for this to work.
Sorry cos I really don't understand, is this hyperfocal dist use when using mf?
If using af do we still need to do cal the hyperfocal dist?
Sorry don't don't understand.
xenith0 said:Ah I see what you mean... Either estimate the distance or you can always make your own distance scale for your lens if you really want to. Like in your example, if the hyperfocal distance is 1.94m, just round up to a convenient distance eg 2m. But if you really want precise distance measurement I guess the only way would be to use a laser range finder?
Sgdevilzz said:That's the problem, how do I know how many rounds I have to turn the focus ring to know which is at 2m?
Sorry, still new to hyperfocal distance measurements.
Right. That. Don't know what is that called. Just came up with a name randomly as i don't have time researching what is that called :/
So anyway, i have a lens which doesn't have the gauge, how do i calculate the hyperfocal distance?
wow, then i would need a super torchlight to do landscapes and cityscapes!What we typically do is to shine a torch light at something we estimate to be hyperfocal dist or slightly further out to be safe, focus on that spot on AF or MF(using AF confirm) then turn off AF. And leave it there.
If the most foreground subject is beyond 3m, wouldn't focusing at infinity will just do the trick? My tokina 11-16's distance scale has only up to 2m before inifinity. I always wonder how to focus at 5m in the above example given by DD123.
wow, then i would need a super torchlight to do landscapes and cityscapes!