Where is Focus Distance in EXIF data.
selmslie wrote:
I can see it in the raw EXIF for my Sony A7 II and III, my Nikon Df and even my Fuji X100T.
When I convert to JPEG and save for internet display (not at full resolution) most of the EXIF information disappears to save space.
I wish that camera manufacturer would make cameras that display the distance that lens is focused at on the LCD or viewfinder. I can estimate distance quite well but I can't set that distance on the lens as well using the marking on the focusing ring (and of course many new lenses don't even have any distance marking on the focusing ring).
BebuLamar wrote:
I wish that camera manufacturer would make cameras that display the distance that lens is focused at on the LCD or viewfinder. I can estimate distance quite well but I can't set that distance on the lens as well using the marking on the focusing ring (and of course many new lenses don't even have any distance marking on the focusing ring).
For most all situations the AF is far more accurate than trying to set a manual distance even on lenses marked as they are marked with large gaps like 10' then 20'. So in between is a WAG.
Architect1776 wrote:
For most all situations the AF is far more accurate than trying to set a manual distance even on lenses marked as they are marked with large gaps like 10' then 20'. So in between is a WAG.
There are situation where it's advantagous to prefocus and not rely on AF. For example shooting without looking into the viewfinder at all. As I said the marking on the focusing ring has very large gap and also the scale is non-linear.
BebuLamar wrote:
There are situation where it's advantagous to prefocus and not rely on AF. For example shooting without looking into the viewfinder at all.
So you just WAG the distance.
AF allows for prefocus then holding it.
PS, there is a screen on the back of most cameras so no looking into viewfinder is required.
You might want to try that if you are adverse to viewfinders.
Architect1776 wrote:
So you just WAG the distance.
AF allows for prefocus then holding it.
PS, there is a screen on the back of most cameras so no looking into viewfinder is required.
You might want to try that if you are adverse to viewfinders.
Prefocus you have to point the camera at the subject from your position. That is something I want to avoid. I want to do the focusing pointing the camera somewhere else. When pointing the camera at the subject to take the picture I don't even want to look at the camera.
BebuLamar wrote:
I wish that camera manufacturer would make cameras that display the distance that lens is focused at on the LCD or viewfinder. I can estimate distance quite well but I can't set that distance on the lens as well using the marking on the focusing ring (and of course many new lenses don't even have any distance marking on the focusing ring).
You don't need to know the distance.
All you need to do is switch to manual exposure and focus on an object at your target distance.
Or you can just autofocus on your target and turn off autofocus.
BebuLamar wrote:
Prefocus you have to point the camera at the subject from your position. That is something I want to avoid. I want to do the focusing pointing the camera somewhere else. When pointing the camera at the subject to take the picture I don't even want to look at the camera.
So anything at the same distance as "somewhere else" will be in focus, but not the subject. That makes no sense.
selmslie wrote:
So anything at the same distance as "somewhere else" will be in focus, but not the subject. That makes no sense.
Basically I want to set the focus distance without having to point the camera at the subject. I would be shooting from the waist and not looking at the camera. I would prefer the distance display on top of the camera but if I have to see it in the viewfinder then I would point the camera perhaps down look at the viewfinder set the distance that I know to be the correct distance then the wear the camera at waist level and release the shutter.
BebuLamar wrote:
Basically I want to set the focus distance without having to point the camera at the subject. I would be shooting from the waist and not looking at the camera. I would prefer the distance display on top of the camera but if I have to see it in the viewfinder then I would point the camera perhaps down look at the viewfinder set the distance that I know to be the correct distance then the wear the camera at waist level and release the shutter.
I did that all of the time with a Rolleiflex but I still started by actually focusing on something approximately the same distance from the camera as the target. Then I shot at a small aperture.
Worked for medium format film where you can actually look at the image on the top of the camera to frame the scene and nobody would realize their picture is being taken.
Not practical for small format digital because you can't frame the scene and you have to use a wide angle lens.
You are better off just using the wide angle lens on your smart phone. At least it will be in focus and it has a very deep DOF.
Even an iPhone raw file reports the distance
selmslie wrote:
I did that all of the time with a Rolleiflex but I still started by actually focusing on something approximately the same distance from the camera as the target. Then I shot at a small aperture.
Worked for medium format film where you can actually look at the image on the top of the camera to frame the scene and nobody would realize their picture is being taken.
Not practical for small format digital because you can't frame the scene and you have to use a wide angle lens.
You are better off just using the wide angle lens on your smart phone. At least it will be in focus and it has a very deep DOF.
I did that all of the time with a Rolleiflex but I... (
show quote)
I learned to estimate the frame and distance.
BebuLamar wrote:
I learned to estimate the frame and distance.
How is that working for you? You haven't posted any images.
BebuLamar wrote:
Basically I want to set the focus distance without having to point the camera at the subject. I would be shooting from the waist and not looking at the camera. I would prefer the distance display on top of the camera but if I have to see it in the viewfinder then I would point the camera perhaps down look at the viewfinder set the distance that I know to be the correct distance then the wear the camera at waist level and release the shutter.
How do you know some random object in some other random direction is the same distance as the subject.
This has gone way off of EXIF data in the photo.
So start your own thread on random guessing of distance.
Architect1776 wrote:
This has gone way off of EXIF data in the photo.
Actually, not far off. If the information is available for the EXIF, why not display it on the screen?
In fact, in manual focus mode mode, my A7 III displays the focus distance in meters under a moving slider. My Z7 shows the slider but only no numbers.
Alphabravo2020 wrote:
I'm thinking that the focus distance should be recorded somewhere in the image EXIF data as long as the lens and body are communicating. In this case I used a Sony A7iv and a Sony 50mm GM f1.2.
Shouldn't the camera be able to figure out the focus distance from the information it gets from the lens? Anyway I don't see it there or maybe I don't recognize what it is called.
Gratuitous example image supplied upon request.
First of all commercial cameras don't measure distance to subject. Distance markings have been on lenses before autofocus was invented and are algorithmic estimates based on the focus range of the lens. Those markings are rough approximations shown on a scale similar to a "LOG" scale. Anyone ever try to interpolate an in between value from a "LOG" scale? Ever notice how the infinity mark on your lens focus ring is not actually when the lens is focused at infinity? Before autofocus, if you wanted to do discrete grab and shoot street photography you'd set a high aperture (w/ corresponding SS) and set your focus ring at the hyperfocus distance. Saving subject distance (which is not accurate) to EXIF data would not have significant value.
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