Question on controlling focus

I have some homework for my photography class I can't come across. I need to take several pictures of a composition of 3 objects (that I can arrange however I want) such that the picture is the same all the time (same distance, same light). In pic #1 all 3 objects are in focus, in pic #2 only objects 1 and 2 are in focus, in pic #3 only objects 2 and 3 are in focus and in pic #4, and here is the problem, only 1 and 3 are in focus. I initially thought I could place the objects in a triangle disposition but still, pic #4 wouldn't work... How could I place them and play with the diafragm/focal distance/focal leght so that I can take all 4 pics??? (Note: I do not have a tilt shift lens)

Thanks

Marta

Just change the aperture to something smaller(ie bigger F number eg f11).

You need to read up on Depth of Field.

I think Marta understands DOF. The problem here is that the teacher gave an assignment that is like a puzzle. If you read the assignment it seems like the issue is which objects are in focus when.

Marta needs to figure out the solution. I think Marta knows how to control DOF. But to have objects 1 and 2 in focus in one picture and objects 1 and 3 in focus in another, seems impossible.

it seems the only way to do this would be to merge 2 images. i assume this isnt allowed. other than that, either your teacher is ****ing with you or he/she expects you to come back with an answer as to why it cant be done.

If the photos don't have to be taken from the same location, arrange objects, take 1-3, move around table, take 4.

You could get real literal with the rules ya know. No implied guidelines = open to interpretation = outside the box.

Are you allowed to use a tilt-shift lens?

Josepi wrote in post #10030631
If the photos don't have to be taken from the same location, arrange objects, take 1-3, move around table, take 4.

You could get real literal with the rules ya know. No implied guidelines = open to interpretation = outside the box.

mlfraga wrote in post #10029172
I need to take several pictures of a composition of 3 objects (that I can arrange however I want) such that the picture is the same all the time (same distance, same light).

seems like he/she needs to set up the shot and frame it exactly the same way for each shot. same picture, different focus. no rearranging the objects.

and if your teacher expects you to spend money on a t/s lens, they are crazy.

Can one of the objects be swinging from a string?

tracknut wrote in post #10030891
Can one of the objects be swinging from a string?

love it. very creative thinking.

A cheap way of getting soft focus when I was taking film was to smear a little vaseline on the lens, and you could use that technique here.

You could set your aperture so that all three objects are in focus, and then smear a little vaseline on your lens (actually I would use a filter) where item 2 is, thus rendering it out of focus but leaving the other two in focus.

not sure this answers your question, but don't forget to shoot staight down at the objects from above to solve a requirement!

dave

Love that string idea.

Josepi wrote in post #10030631
If the photos don't have to be taken from the same location, arrange objects, take 1-3, move around table, take 4...

That's what I was thinking. Have all three objects in an equilateral triangle. Take shot #1 from wherever, using a small aperture to get them all in focus (or from overhead, so they're all on the same focal plane. Take shot #2 from the side of the triangle where #1 and #2 are the same distance from lens. Take shot #3 from the side where #2 and #3 are the same distance, then move around and take shot #4 from the position where #1 and #3 are at the same distance.