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Camera Recommendation for high resolution focus stacking

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Camera Recommendation for high resolution focus stacking
« on: 11 / February / 2015, 21:09:56 »
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Looking for a camera recommendation for focus stacking.
The camera firmware list is extensive and a bit overwhelming.

Shooting jewelry items in a controlled light environment for ebay/ecommerce websites.

I'm based in Los Angeles and currently using an EOS Digital Rebel XTi with EFS 60mm macro lens.
Image capture is ISO 100, manual time and aperture, and multiple manual focus shots with Helicon Focus processing. Lightroom into Helicon into Photoshop workflow at 300 dpi.
Good results but I need to simplify and automate the capture process.

Ideal camera could be older, high volume model with hi-res capture that is currently available on craigslist/ebay for less than $200 USD.

Any notes or suggestions are greatly appreciated.

Thanks,

John

Re: Camera Recommendation for high resolution focus stacking
« Reply #1 on: 11 / February / 2015, 21:56:02 »
Good results but I need to simplify and automate the capture process.
As long as you are okay with the automating your workflow part on the PC, automating the capture process on the camera is probably the easy part.  You could script it all in the camera but I suspect using the Lua scripting in chdkptp would make a whole lot more sense.

http://chdk.wikia.com/wiki/PTP_Extension#chdkptp


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Ideal camera could be older, high volume model with hi-res capture that is currently available on craigslist/ebay for less than $200 USD.
That should not be a problem.  What is "hi-res" though?  For ebay/ecommerce, that's something from any camera with a 10M sensor or better and macro capability?  Which probably means pretty much any Canon P&S from the last 8 years or so?
Ported :   A1200    SD940   G10    Powershot N    G16

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Re: Camera Recommendation for high resolution focus stacking
« Reply #2 on: 11 / February / 2015, 23:45:24 »
Ideal camera could be older, high volume model with hi-res capture that is currently available on craigslist/ebay for less than $200 USD.
You might also consider canon refurbished and clearance: http://chdk.setepontos.com/index.php?topic=11768.0
Don't forget what the H stands for.

Re: Camera Recommendation for high resolution focus stacking
« Reply #3 on: 16 / February / 2015, 20:25:10 »
Thanks for the Links.

I'm leaning towards a G15.
I can get one around $200; it's the right size and heft and I can use the live video preview for precise pre-focusing.

My plan is to create a script to run focus bracketing across a depth-of-field of about 40-50 mm, at 1 mm intervals (exact settings tbd).

FWIW, this is the work-flow model:
1. position item, camera, lights.
2. focus camera on closest point of item.
3. manually set TV & AV (ISO preset to 100, file set to RAW)
4. run script, capturing 40-50 images.
5. import images into LightRoom, discarding excess frames.
6. crop and adjust image 1, then copy adjustments to the rest of the images.
7. import adjusted images into Helicon Focus, save deep image and open image in Photoshop for touchup.

Rinse and repeat.


Re: Camera Recommendation for high resolution focus stacking
« Reply #4 on: 16 / February / 2015, 20:55:39 »
I'm leaning towards a G15.
I can get one around $200; it's the right size and heft and I can use the live video preview for precise pre-focusing.
One of the nicest high end Powershots Canon has made.  Probably only just behind the G1X-II, G1X and G16 - and not by much.   And for  $200 you get a much less expensive option that runs CHDK (only the G1X also runs CHDK from that list).

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My plan is to create a script to run focus bracketing across a depth-of-field of about 40-50 mm, at 1 mm intervals (exact settings tbd).
I'm not exactly sure you will get 1 mm increments - the camera focus motor has a resolution limit and this might be less that what you can achieve.    But I don't have a G15 to try this out on - others may be able to comment better than I can.
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Camera Recommendation for high resolution focus stacking
« Reply #5 on: 16 / February / 2015, 21:29:39 »
One possible problem is that when you change the focus of the camera, you also may be slightly changing the focal length of the lens, and that may mean that the stacked images won't quite line up.  A solution would be to fix the focus, and move the entire camera.  This may all be theoretical, but I know that one guy who uses focus stacking to photograph snowflakes uses the whole-camera method.  Of course a script isn't all that useful for that method.


Re: Camera Recommendation for high resolution focus stacking
« Reply #6 on: 01 / May / 2015, 16:03:19 »
I don't know what magic is embedded in Helicon Focus but it compensates for changes in focal length and slight positioning errors. You can see the slight differences in the stacked images as Helicon processes the stack. In real-time, it looks like a crude flip-book animation; images are overlaid one at a time on the existing composite image. When a stack image is dropped on the working composite, you can see it make corrections of slight differences in image size and position. The finished image is perfect.

 

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