Tommg

Last night I placed my camera on a tripod and took 3 photos of the moon at 1 minute intervals. Now I want to create an image in Photoshop CC that includes all 3 images in 1 image .... 3 pictures of the moon in 3 different positions - one image.

I did this once a few year ago, cannot remember how to do it ... any help is appreciated

melismus Loc: Chesapeake Bay Country

You need to tell us your objective: how will the composite be superior to the components?

DirtFarmer Loc: Escaped from the NYC area, back to MA

Open the three images as layers in PS.
Change the blending options to "Lighten" on the two top layers
I'm assuming the moon doesn't overlap the moon in the other images.

The rotation of the earth is approximately 1/4 degree/minute. The moon's motion is smaller than that so I will neglect it. So in one minute the moon will have moved about 1/4 degree. The moon subtends an angle of about 1/2 degree, so the moon will move something like 1/2 of its diameter in one minute. So it is likely that the moon images will overlap.

Of course in PS you can just move the moon with very little effort.

speters Loc: Grangeville/Idaho

What you talking about is a composite and not photo stacking!

KGOldWolf

Really informative answer; I learned more than I expected when I read the original post.... thanks!

cthahn

You really do not say what you are trying to do.

KGOldWolf

Funny, it seems clear but perhaps I'm just misunderstanding. I read it as he is interested in have his three shots of the moon appear in a single image. He doesn't say he wants the moon as one image. It just sounds like time lapse photography embedded in one final image... three images of the moon as the earth rotates.

I hope tommg responds to clear up the apparent confusion.

Tommg

thank you, appreciate the help, at one point in time I how to do this ... I seem to have CRS

joseph premanandan

Do you mean HDR or Photo stacking?.when you try three different moon shots,you need to have a tripod and remote shutter release device and you have to take three images with three different shutter speeds like 1/100,1/250,1/320 as an example and others may try different shutter speed and you have to keep the composition and the ISO the same using spot metering and use manual focus to infinity and merge them either in photoshop or photomatix or AuroraHDR.when you use the word photostaking,then my understanding is you mean focus stacking and i do not think that you can do focus stacking alias photostacking with moon shots.that is my understanding unless i am wrong

ewforbess Loc: San Antonio, TX

If you took three separate photos, you can create one Photoshop document with all three exposures as layers, then use the layer mask function to erase down to the images on the first two layers.

If you want to bypass Photoshop altogether, you may be able to use the multiple exposure function of your DSLR. You didn't mention which camera you're using, but my Nikon D7000 allows you to input the number of exposures you want on a single frame, then you just make that many exposures that are recorded on a single JPG or RAW file.

Hope that helps!

LoneRangeFinder Loc: Left field

I think it's quite possible that this was the methodology used by the OP originally. Seems way more functional compared to the "darkroom" work.

Tommg

Sorry to be late to reply, been on the road the past couple of days.

Dirtfarmer answered my original question & provided the information that I was looking for - thank you.

The additional information concerning the rotation of the earth (1/4 degree per minute & etc) I found to be very interesting and would be interested in knowing how I could do some additional research on the subject - fascinating!

Some of the other replies while not what I was looking for at the time, were also interesting and gave me several new ideas to try ... thanks to all

tommg

DirtFarmer Loc: Escaped from the NYC area, back to MA

The earth rotates at a pretty constant rate. Tiny variations are caused by tides and atmospheric motions and core motions but can be easily neglected. The rotation is 360 degrees per 24 hours, but that's relative to the sun. Subtract something like 3 minutes and 57 seconds for rotation relative to "fixed" stars (one rotation per year). 24 hours is 1440 minutes, so compared to the sun, the rotation is 360 degrees in 1440 minutes, or 1/4 degree per minute. The moon orbits the earth roughly once every 28 days or 360 degrees in (28days x 1440minutes/day)=40,320 minutes or about 0.009 degrees/minute. Compared to 1/4 degree per minute it's small enough to neglect. The moon and sun both subtend about 1/2 degree. That varies a bit with time since neither the orbit of the moon around the earth nor the orbit of the earth around the sun is circular. Again, for rough calculations the variation is negligible. So that means the moon takes about 2 minutes to move one diameter across the sky.