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ChrisLilley
Joined: 01 May 2010
Posts: 680
Location: Nice, France (I'm British)
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 Posted: Sat Jun 05, 2010 1:46 pm Post subject: Bee on thistle (studio stack) |
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(image links to flickr page with larger version)
This bee had been caught by a spider, and died on this thistle.
Nikon D90, Rodenstock APO-Rodagon-D 75mm f/4 1:1, Nikon PB-4 bellows, StackShot @ ISO 200, 1/10s, f/5.6. This lens is like an enlarger lens, but aimed at duplication. Optimal magnification is 1:1 with a design range of 0.8 - 1.2x. Here it is used at 1x as near as I can judge.
Diffuse natural daylight from a nearby window.
Images developed in Nikon CaptureNX 2. Stack of 66 images in Zerene Stacker, PMax method. First stack with the StackShot, which arrived yesterday. 0.2mm step size.
In fact I shot at 0.05 step size, which was too fine; I ended up using only one in four images for the final stack. Also, due to inadequate support and slight wind from a fan, the subject was slipping from right to left ever so slightly, then a bit faster at the end; the images with the wing in focus had to be discarded.
I see that I have a couple of hot pixels, and in the full 4k version these can clearly be seen as a dotted trail as the subject gradually shifted. Need to edit these out before stacking, next time.
Subject support was suboptimal, the plant was taped to a cardboard box  before getting the StackShot I had been focussing by moving the rear standard of the bellows, so I could mount the subject on a Nikon PS4 slide holder which attaches to the front of the bellows. Here the StackShot moves the entire bellows assembly so the subject needs to be mounted on a separate stand.
I see that ZS has not been thrown by thistle spikes in the background overlaid by a semi transparent bee wing in the foreground. |
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rjlittlefield
Site Admin
Joined: 01 Aug 2006
Posts: 12576
Location: Richland, Washington State, USA
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| Posted: Sun Jun 06, 2010 12:03 am Post subject: Re: Bee on thistle (studio stack) |
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Very nice, Chris. This is the point where we usually suggest moving out of the Beginners forum and up into the regular galleries, Technical and Studio in this case. The galleries get a lot more viewer traffic, so generally you'll get a lot more comments there.
| ChrisLilley wrote: | | Here it is used at 1x as near as I can judge. |
The easy way to measure scale is after you're done photographing your real subject, swap in a ruler, focus that without changing the optics, and take one more picture. Strictly speaking, the scale that you get will apply only to the first frame in the ZS input files list as ordered after stacking, but it will generally be within a few percent for the whole stack.
| Quote: | | ...hot pixels...dotted trail as the subject gradually shifted. Need to edit these out before stacking, next time. |
I assume you have some nice automated way to do this. What is it? Does CaptureNX provide some sort of defect map?
| Quote: | | ZS has not been thrown by thistle spikes in the background overlaid by a semi transparent bee wing in the foreground. |
It depends on the method. DMap often has trouble handling overlapping structures; PMax usually handles them well except for the common "transparent foreground" artifact.
--Rik |
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ChrisLilley
Joined: 01 May 2010
Posts: 680
Location: Nice, France (I'm British)
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| Posted: Mon Jun 07, 2010 6:56 am Post subject: Re: Bee on thistle (studio stack) |
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| rjlittlefield wrote: |
| ChrisLilley wrote: | | Here it is used at 1x as near as I can judge. |
The easy way to measure scale is after you're done photographing your real subject, swap in a ruler, focus that without changing the optics, and take one more picture. |
I wasn't far out. Photograph-the-ruler gave me a magnification of 1.07
| rjlittlefield wrote: | | Quote: | | ...hot pixels...dotted trail as the subject gradually shifted. Need to edit these out before stacking, next time. |
I assume you have some nice automated way to do this. What is it? |
Some raw converters, like dcraw and libraw, have a nice facility where a file of x y positions (and dates!) of hot/black/stuck pixels is read and the relevant pixels nulled out.
CaptureNX does not seem to. I was planning to either zap them one by one in an image editor or, alternatively, use a tool like PixelFixer
http://www.pixelfixer.org/
| rjlittlefield wrote: | | Quote: | | ZS has not been thrown by thistle spikes in the background overlaid by a semi transparent bee wing in the foreground. |
It depends on the method. DMap often has trouble handling overlapping structures; PMax usually handles them well except for the common "transparent foreground" artifact.
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Yes, this is PMax. |
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rjlittlefield
Site Admin
Joined: 01 Aug 2006
Posts: 12576
Location: Richland, Washington State, USA
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| Posted: Mon Jun 07, 2010 7:54 am Post subject: |
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Thanks for the information about PixelFixer. That one had escaped my attention.
--Rik |
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