Comparison

[scitch]

I have a grant at work that allowed me to purchase some photo and video equipment. Today was like my birthday. I got a Raynox 250, a Tamron 90 mm macro, a reversing ring, and Photoshop CS5. I watched this simple video (even simple enough for me!) on stacking in PhotoShop and went back and re-stacked an old series to compare. I wasn't very impressed. What do you think?

I loved "auto-levels" in my old version (CS1?) and can't find it in CS5. Is it gone? (I know auto-levels is lazy, but it works like magic!)

This is a PhotoShop CS5 stack. I could probably fix some of the OOF areas by hand . . . but I don't yet know how to hand-stack.



I'll post some pictures with the Raynox and Tamron later to see if I'm getting the most out of them.

Actually, here's a shot with the Tamron on my Sony a200 with the flash bounced off of a sheet of white paper (I also got a ring light today that I'll play with soon). It was cropped, auto tone, auto contrast, auto color, and resized to 800 pixels wide. I was hoping to see some compound eye facets. By the way, the subject is a common butterfly that my 8-year-old daughter caught using the swaying back and forth technique someone on the forum discussed. She has caught two butterflies and touched a damsel fly with that technique. (I don't know what a damsel fly was doing at my house in the desert nowhere near any water.)



With CS5, I can edit RAW images. What are the advantages? If I edit one RAW image to a point that I like, can I easily apply those same settings to the rest of the images before stacking? Or should I stack and then edit?

Sorry for the long list of ignorant beginner questions.

Mike

[elf]

but I don't yet know how to hand-stack.

snip...

With CS5, I can edit RAW images. What are the advantages? If I edit one RAW image to a point that I like, can I easily apply those same settings to the rest of the images before stacking? Or should I stack and then edit?

Hand stacking is quite easy, but tedious. Rik recently described a method I've been using for years where you create a duplicate layer and toggle it's visibility on and off. This allows you to quickly see the differences between the layers. The bottom layer will be the working layer where you mask out the OOF areas.

Edit the RAW images before stacking. CS5 (and previous versions) allow you to apply the changes to multiple images. If you have the RAW files for the butterfly image, you may be able to recover more details in the blown out areas.

[rjlittlefield]

I saw this one earlier but forgot to reply to it, sorry.

I have seen several comparisons of Photoshop's automatic focus stacking against various dedicated stackers such as Zerene Stacker, Helicon Focus, and CombineZP. None of them were very complimentary to Photoshop. Reports say that CS5 is significantly improved over CS4, but compared to the dedicated stackers it is still more vulnerable to artifacts such as "stacking mush" (failure to preserve detail that is easily visible to a human).

It also has some unique artifacts such as nonlinear stretching of the geometry. See for example Michael Erlewine's "The Art of Focus Stacking", page 42. But I don't see anything like that in the image posted here.

I'm unclear what you mean by "can edit RAW images". If you mean things like setting brightness, contrast, and color balance, then those are definitely good things to do before stacking. If you mean manually cloning, say to clean up a dirty specimen, then it's better to wait until after stacking.

ZS does not accept RAW input, so what you'll do with brightness, contrast, and color balance is to incorporate those into the RAW conversion you do in Photoshop, generating temporary TIFF files to be stacked. HF does accept RAW input, but as far as I know it does not incorporate modifications made in Photoshop, so again you would take the approach of converting to TIFF in Photoshop, then stack the TIFFs.

As elf says, hand stacking is simple but tedious. Freehand shooters routinely use it up to a half-dozen frames or so. Beyond that hand stacking becomes progressively less viable. If you're stacking static specimens in a bench setup, then there's no reason to spend the time -- it's much faster to run one of the automatic methods, then touch up the results if necessary.

--Rik

[scitch]

Thanks. I should have been clearer about the hand stacking. I will never hand stack an entire image, but I'd like to be able to hand-modify the masks that photoshop automatically makes. I wish each one of the masked areas had handles that I could drag to whatever shape I want. I didn't really get CS5 to stack with, but I had to try it. I honestly thought that this example was really poor stacking. I posted the Zerene version of this stack about a month ago and it doesn't have the OOF areas.
I hear people talking about how great it is to edit the RAW images and I just didn't know why. My camera will take them, but my CS1 wouldn't open them. So, I just wondered what all the hype is now that I can.
In a moment, I'm going to post a series that I did last night of the bee with the Raynox on the Tamron. Besides knowing nothing about microscopes, photoshop, or stacking, I also know nothing about photography. So I've been playing around with F-Stops to see the results.

Mike

[rjlittlefield]

To explain about raw images requires quite a few words. I suggest to read http://en.wikipedia.org/wiki/Raw_image_format and then perhaps to run a Google search on something like advantages of raw image. After you have read for a while, then post again so we can cover what the other sources did not.

Very briefly and approximately, the big advantages of raw images are confined to adjusting brightness, contrast, and color balance. Once you get into editing operations like resizing, sharpening, cloning, masking, and so on, then you're no longer working with raw images but rather with ordinary RGB images that were created from the raw images that the camera shot.

Compared to shooting JPEG, shooting raw allows you to get better gradation -- typically 4096 levels at each pixel in raw versus only 256 in JPEG. However, to actually get this advantage you have to do the raw conversion in 16-bit mode and retain the image in 16 bits as long as you're editing it. If you convert to 8 bits at any point, then you've lost it.

--Rik