Hyperfocal distances on x7 lenses

[DamesNY]

Hi guys, we were asked to do a dronie of a flag and we didn’t have anybody to pull focus. I was under the impression that with f8 on the x7 35mm hyperfocal was 30ft +.

Does this sound right? I couldn’t find anything on x7 lenses. Any ideas?

 

[Ray Maxwell]

Here is the definition of hyperlocal distance from Wikipedia:

"In optics and photography, hyperfocal distance is a distance beyond which all objects can be brought into an "acceptable" focus. As the hyperfocal distance is the focus distance giving the maximum depth of field, it is the most desirable distance to set the focus of a fixed-focus camera.[1] The hyperfocal distance is entirely dependent upon what level of sharpness is considered to be acceptable."

Please note that the hyperlocal distance is not a fixed number. You choose a circle of confusion that specifies the sharpness that you have decided is acceptable and then plug it into the formula and it gives you the hyperlocal distance.

Here is the Wikipedia formula: Hyperfocal distance - Wikipedia

Ray

 

[DamesNY]

do you happen to have a numerical suggestion as an answer?

 

[mmarian]

do you happen to have a numerical suggestion as an answer?

It is not so simple to a give specific number because, as he says it depends on many factors, namely your expectation and what you are willing to accept as sharp enough. Hyperfocal distance is not an exact number because what's sharp enough for you might be not sharp enough for others hence his not number specific answer. Lens is only 100% sharp at one distance though with increased f stop the perceived or what might be commonly accepted as acceptable sharpness starts to cover wider distance range if you want. All of this also depends on angle of view of the lense and of the distance it is focused to. But for most intents and purposes you can follow any chart available just google it up and you'll be close to ok...

 

[Ray Maxwell]

I would point out one more optical fact that many people don't understand. When you stop a lens down the depth of field increases. However, at a certain aperture the lens starts to be diffraction limited. This means if you stop down beyond this point the plane where you are focused actually starts to become more blurry. This happens at about f 5.6 to f 8 with the X7 lenses.

For a full write up see this web site: Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks

For more technical topics see this web site: Digital Photography Tutorials

Ray

 

[DamesNY]

so after some basic tests, if anybody is curious...30 feet is what I'm getting.