TOO MANY PICTURES IN A STACK?

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florigen
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Location: Traverse City, MI

TOO MANY PICTURES IN A STACK?

Unread postby florigen » 26.01.2009 16:27

I'VE SEEN A LOT OF COMPOSITES MADE UP FROM A VERY LARGE NUMBER OF PHOTOS. iT SEEMS THAT THE DOF OF EACH PHOTO SHOULD OVERLAP ENOUGH TO CUT THIS NUMBER DOWN. TOO MANY PHOTOS WOULD INCREASE THE CHANCE FOR MIS ALIGNMENT AND FOR GHOSTING PROBLEMS. I KNOW YOU CAN CONTROL DOF UP OR DOWN BUT I WOULD FAVOR KEEPING IT LARGE. iS THERE A MATHMATICAL WAY TO PREDICT THE NUMBER OF PHOTOS NECESSARY FOR A STACK?

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Dan Kozub
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Unread postby Dan Kozub » 27.01.2009 13:22

I think it is possible to calculate DOF and a number of images to cover the subject. But it depends on the lens and the camera. I would suggest to make many shots with optimal aperture to get max resolution (f5.6-8) and then select every second or every third source if the they overlap too much.

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p_p_p
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Unread postby p_p_p » 03.02.2009 06:14

after using Helicon Focus for almost 2 months now and greatly enjoying its power and simpleness,
i still can't figure how to shot properly the photos to work with (stack), each one with its appropiate depth of field step.
Either with few or plenty shots, the result/built image from H. F. will always end up with texture loss or smeared lines (see details ↓)...
(white scratches or points in the sample pictures attached to this post are not part of the problem; just dust on the object)
Any suggestion for a general method concerning this kind of small objects shooting with medium format camera (Mamiya RZ67) or 4x5" (SINAR P2) using digital back about 40x30mm size (PhaseOne P21) ?
A big thanks' in advance for your help.
Attachments
6imgsstackresult_detail_s.jpg
6imgsstackresult_detail_s.jpg (152.32 KiB) Viewed 11043 times
6_imgs_stack_result.jpg
6_imgs_stack_result.jpg (121.34 KiB) Viewed 11043 times
Helicon Focus 4.0.1 (1220) Pro Multiprocessor • SINAR P2 & Mamiya RZ67 w. db PhaseOne P21, Canon 1D MarkII • Mac Pro 2x2.66Ghz Dual Core, iMac 2.0GHz Intel Core 2 Duo, OS X.5.6 • Eyes v.2 (dark).

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Dan Kozub
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Unread postby Dan Kozub » 04.02.2009 13:41

I would like to test this stack myself. it would be great if you could upload JPEG files to http://heliconsoft.com/ftp.html. Password-zip it if you do not want to make it public.

BTW, new 4.70 version is out. It has better interpolation routines.

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p_p_p
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Unread postby p_p_p » 04.02.2009 14:48

thank you Dan for your constant help.
i uploaded 8 JPEG files in a zip folder called <p_p_p_smear_texture_pb.zip>
BTW, new 4.70 version is out. It has better interpolation routines.
On Mac, we are not that far... only 4.0.1... :-(
which i just tried now and it looks like things are done more gently than on previous version.
But still texture loss does front page...
Again thanks' a lot for your expertise and advices.
Philippe.
Helicon Focus 4.0.1 (1220) Pro Multiprocessor • SINAR P2 & Mamiya RZ67 w. db PhaseOne P21, Canon 1D MarkII • Mac Pro 2x2.66Ghz Dual Core, iMac 2.0GHz Intel Core 2 Duo, OS X.5.6 • Eyes v.2 (dark).

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Dan Kozub
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Unread postby Dan Kozub » 05.02.2009 14:22

Thanks, I've tested your stack on the 4.70 win version. The loss of texture can be easily explained. The scratches and dust on the glass make the program think that this small area should be taken from different source image. You may try to reduce its size by setting smaller Radius value. But this can give you worse artifacts somewhere else. So my suggest to remove the glass or to use brushes of Helicon Focus to clone these areas from the right source images. As to the broken line, I was not able to reproduce it so far. If this bug persists I need to know the settings you are using (alignment params, radius, smoothing, method).

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p_p_p
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Unread postby p_p_p » 06.02.2009 13:09

Dan , thanks' a lot for your time on this.
The scratches and dust on the glass make the program think that this small area should be taken from different source image.
ah... what i thought was not part of the drama, had the main character on stage... :(.
So i'll do a much better cleaning next time.
You may try to reduce its size by setting smaller Radius value.
ok. So far, i did not play with parameters, but as you say, it might bring worse artifacts on no-need-to-fix places... Anyway, i will try.
So my suggest to remove the glass [...]
Well, that's part of the job, a shot with the plastic cover.
Could a similar advice for a fashion photographer be: "choose a girl with no hair" ? Just joking...
[...] or to use brushes of Helicon Focus to clone these areas from the right source images
But in the latest version 4 for Mac, this brush/clone tool is gone.
Or is it there and could not find it?..
If this bug persists I need to know the settings you are using (alignment params, radius, smoothing, method).
Ok, thank's for help again.
According to my latest test with better result and much less texture loss in macro situation (no test yet with the plastic cover...):
if dof is the depth of field distance,
dofEnd the depth of field ending, further point from lens,
dofMiddle point at half the depth of field distance,
dofStart the starting point of depth of field, closest point to the lens,
then, roughly, 1/3 of the shots should be made from dofEnd <-to-> dofMiddle and the rest, 2/3 of the shots, from dofMiddle <-to-> dofStart .

But this a very empiric approach and all suggestions are welcome for a much sharper world !
Thanks' for your reading and experiences.
Ph.
Helicon Focus 4.0.1 (1220) Pro Multiprocessor • SINAR P2 & Mamiya RZ67 w. db PhaseOne P21, Canon 1D MarkII • Mac Pro 2x2.66Ghz Dual Core, iMac 2.0GHz Intel Core 2 Duo, OS X.5.6 • Eyes v.2 (dark).

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Dan Kozub
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Unread postby Dan Kozub » 06.02.2009 14:13

The brush should be on the Retouching tab. The brush is available in Pro version but you should be able to test it also in Lite version. I will check if this is so.

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p_p_p
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Location: Tokyo

Unread postby p_p_p » 07.02.2009 02:59

[...] The brush should be on the Retouching tab.
ooppss... thought it was for something else... Sorry, i should have checked better before asking...
Yes, those tools (copy/clone) will be handy in no-solution situations.

Just one thing:
When Helicon Focus v.4/Mac Help file will be online ?
Now the Help is just related to v.(?)/Windows..
Helicon Focus 4.0.1 (1220) Pro Multiprocessor • SINAR P2 & Mamiya RZ67 w. db PhaseOne P21, Canon 1D MarkII • Mac Pro 2x2.66Ghz Dual Core, iMac 2.0GHz Intel Core 2 Duo, OS X.5.6 • Eyes v.2 (dark).


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