Orquid "Phoenix"

Orquid "Phoenix"

by ceinmart

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

Take the 2-minute tour ×
Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. It's 100% free, no registration required.

I am taking a series of photos using a dSLR camera attached to a microscope that will be used in a stack to produce a single image with high depth of field. Can anyone recommend a level of resolution that I should use for each shot? The camera has a capacity of 18 megapixels, but I am concerned that if each picture is shot at such high resolution, I may introduce noise and the size of the final image will be huge. The software I am using does not address this. I expect to combine somewhere between 6 and 15 images.

share|improve this question
    
My only comment is that I would expect that the lower resolution you use, the fewer shots you need to make it look seamless. –  Itai Jan 24 '13 at 3:09
add comment

2 Answers

Always use as much data as you can. It's actually easier to reduce noise when there's more information to begin with. (Reducing resolution is a brute-force noise removal tool, throwing away both noise and signal.)

If you're concerned about the size final image, reduce the resolution at that point.

share|improve this answer
1  
The final image may be huge, but if it's a satisfactory end result you can flatten the file and it will be no bigger than a normal image file. –  BobT Jan 24 '13 at 0:55
    
I was interpreting the question as suggesting that a single 18mpix image seemed huge, but, yeah, that too. –  mattdm Jan 24 '13 at 17:18
    
I figured he was commenting on the stack of layers, one for each image, which would have been pretty big, depending... –  BobT Jan 25 '13 at 2:10
    
Yes, also possible. –  mattdm Jan 25 '13 at 2:11
add comment

I don't have too much to add, but I have some limited experience with focus stacking on microscopes that I can share.

I've done focus stacking on an SEM, the following image is a stack of only two images. I wish I had a third to fill in the blur in the middle.

Image of a flower I took with a scanning electron microscope. The near foreground and the 'sky' background are one image. The subject is a second exposure. I wanted to maximize blur of the background and maximize the clarity of the foreground. SEM Image of Flower

Unless you are optically photographing a fixed subject, the subject will drift, so it is important to take the images quickly, and sequentially to minimize the impact. Frame a bit wider than normal so the final crop can be perfect.

mattdm has the answer you are looking for: Use full resolution as long as possible. Focus stacking will not reduce noise, it will improve image clarity by chooing regions that have better focus. Reducing noise would require a set of exposures at each focal distance to average out the noise- get more data for each pixel.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.