Random Question on Focus Distance

SoulfulRecover

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If you were to stand in front of a mirror, lets say 5 feet away, would your cameras focus distance be the 5 feet to the mirror or would the focus distance be at 10 feet because of the distance to the mirror then back?

:popcorn:
 
If you want a selfie, the distance to set the focus is 10 feet.

If you want a nice, sharp shot of the mirror and its gorgeous, 1920's carved, gilded frame, focus at 5 feet.
 
And turn off the On-Camera flash.
:)
 
This and forget the mirror.
 
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But wouldn't you want the focus to be on the reflective surface, where the image now originates?

Edit: and no im not taking selfies haha. Thought this would be an interesting discussion
 
Focus should be to the target/subject, which would be the mirror not you. Your just the afterthought in the photo with a mirror.

The exception might be one of those goofy @$$ carnival fun house mirrors.
 
Of course today most new lenses don't even have focus distance scales on them.
A minus of AF is not being able to just stand in front of a mirror with a camera, focus on your image in them mirror, and then look at the distance on the lens distance scale.

Some kinds of 'technological progress' are diminishing people's common sense.
 
But wouldn't you want the focus to be on the reflective surface, where the image now originates?

Edit: and no im not taking selfies haha. Thought this would be an interesting discussion

Hmmmm...no, this is a misunderstanding of the entire process; the point of origin might be considered the mirror, but there's a final leg in the light's journey...the "image" that counts is the distance from the camera, to the mirror, and then BACK to the camera's focal plane.

This issue comes up now and again. Look at my answer, again. I'm serious. Dead serious. Five feet is for a good, crisp image of the MIRROR and its frame, and anything at 5 feet. For a crisp image of you and the camera, the distances need to be added up: 5' + 5' = 10 feet.

Imagine if I gave you five dollars on your way to the liquor store, plus I gave you five more dollars upon your return home from the lower store.

How many dollars would you have once home from the liquor store? 10 dollars.
 
Who would have any dollars left after going to the liquor store? this assuming you took the other five bucks and ran back to the store...

I took some crowd shots in a mirror at an event but it's been a long time ago... I think I focused on the edge of the mirror and reframed. So yeah, the focus was on the surface of the actual object (mirror) not what you see in the distance in the mirror (reflection).

Same thing with puddles. I think. I don't claim to be an expert puddle photographer.
 
Oh, wait a minute, I wasn't thinking of depth of field. I don't know what f stop I used. I would guess at least midrange or smaller since I was shooting crowd shots at the time.

So I don't know, let's just go to the liquor store and make one of Gryph's flaming volcanos and then we could figure it out.
 
If you were to stand in front of a mirror, lets say 5 feet away, would your cameras focus distance be the 5 feet to the mirror or would the focus distance be at 10 feet because of the distance to the mirror then back?

:popcorn:

Do you seriously NOT know the answer? JFK, this was settled decades ago. But then, popcorn posts are fun too!

I want to go to the Seahawks game, at C-Link field 155 miles away. Friends tell me I can get there and back to my house by driving only 155 miles! My friendz iz smart!

Ooopsies--Seahawks LOST to the Falcons this weekend! Hah!
 
In all honesty no I don't know but I am assuming its the distance to the mirror plus the distance to the object.

BUT it could be the distance just the reflective surface since the mirror is now acting as a picture/painting/whatever of what its reflecting

:allteeth:
 
think about from what you already know. #1 Cameras do NOT measure distances. Stand in front of a mirror about 5' away. Does your reflection look like it is 5' away or does it look like it is 10' away? Pointing the camera at the mirror and letting it auto focus works. THEREFOR it the SURFACE of the mirror that is being focused upon. Yes, DOF is a factor of where a focaos pont(s) are but it does not change the physics of it. At any rate a mirror is nothing more than a 2 dimensional picture to a camera, just the same as if you aimed it at a picture on the wall! DO not overthink things.
 
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