Bruce, Dennis is right, yes the image is Upside down & Reversed left to Right on the screen, but turn it 180 degrees and it's correct. Just try holding a negative with the emulsion side away from you, image upside down, thats the same as a focus screen, now revolve it the 180 degrees and everything is correct.
Add a mirror and you only correct the one dimension hence left & right are switched (backards image).
The real problem here is the misunderstanding of the vernacular. Upside down does not mean turning your head 180 degrees so your skull is pointing at the ground. You're changing your perspective when you do that, which is not what the camera lens is doing. Bruce is correct in that the lens (all lenses) reverse the image in both vertical and horizontal planes.
I'm actually bored enough today to have spent 4 minutes putting together visual aids.
First image is a flower in a vase, as we would see it with just our eyes.
Second image is what would be considered upside down. Notice that there is no side to side reversal.
Third image is what would appear on the ground glass of a view camera.
Good drawings. Yes as I said we are just saying the same thing differently. To me the second picture is not just upside down it is flopped. It is upside down and backwards. The 3rd image is merely upside down. If you actually take a piece of paper and make that drawing in picture #1 and then spin it round till it is upside down you get picture #3. If you spin it round upside down and turn it over you get picture #2. That is if you can see through the paper.
Yes, but Dennis, I think you're thinking of it as a function of perspective. If you are looking at something and you turn your head upside down (you know what I mean) then you are correct. But that's not what a lens does. The lens does not rotate the image, it passes light through so that light that strikes on the left exits on the right, and top/bottom.
As I said, a problem of semantics and perspective. Thanks for the compliment of the drawing. I think I should give up photography and become a painter. :D
Finally, cleared up with drawings. I did not jump in on this because I have found that sometimes to work out problems it is best to maintain a good watch to work ratio!
thanks for the drawings. I always considered the image to be flipped, but now I understand that it's actually the very same image that will appear on the print...just rotated 180 degrees.
Well I am thinking of the plane as a 2 D plane. If a child shows you a drawing and you tell him to try looking at it upside down, I think only the very rare child would turn the drawing over and look at the back. If I show my friend a photo with unclear gravity and he orients it bottom up and I tell him he is looking at it upside down, he would be a joker to turn it over and look at the back of the print and say, Ah you are right it does look better.
To me upside down is to spin a flat object around and look at it upside down. If you were to take a famous flower painting to a dealer and have it upside down you would have it like drawing number 3. IF it was instead like drawing number 2, when the dealer turned it round the right way he would exclaim "But it is backwards! It must be fake"
So that I think is how my head sees upside down. Now if you are talking about turning a coffee cup upside down that is a different matter. Or if my wife says I would prefer you have me upside down tonight honey I would be confused. You mean like yen yang or like canines?
I understand what your wife means. :o
Originally Posted by dpurdy
I've more often heard the term "laterally reversed" rather than 'backward' It might not make any difference in this conversations... so I'll just go back to my private fantasy.
Being from Los Angeles would give you more insight in these matters. Now if she said she was wanting upside down and backwards. I think I would be in real trouble.
Since this is now my thread about anything to do with view cameras (although I do like the turn it's taken recently); a question about film.
Do people shoot color negative film in large-format cameras? Is it common? It seems to me that the big landscapy/'calendar photo' genre photos would be shot on something like Velvia. But unless you have a 4x5 projector, it would seem printing would have to be done digitally for the most part, wheras you could put a sheet of color negative film in a 4x5 enlarger.