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 Replies: 75 / Views: 10,217 |
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Pillar of the Community
 2087 Posts |
I finally got around to taking the lens back out to the greatest extension I could assemble. I am now confident that it probably can be pushed further. However diffraction is a significant issue. For that reason I won't be using the lens beyond 5X. One other point I would note I think as a coin lens you can get the best out of the lens with a mirrorless camera. A standard DSLR due to the larger registry distance ( due to the mirror housing) will prevent you from using the lens at lower magnifications. I believe you can see the effects of diffraction in this 7X shot:   |
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Pillar of the Community
United States
9395 Posts |
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I believe you can see the effects of diffraction in this 7X shot: This shot looks pretty good, considering it's a 100% crop at 7.2X. All My 10X stacks with microscope objectives are fuzzy when looking at a 100% crop, compared to low magnification shots (at 0.5x, for example). Even the highly-regarded 10X/0.28 Mitutoyo is not sharp, even though it seems to have the best (or maybe 2nd best?) resolving power of any 10X infinite objective I have. |
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Pillar of the Community
 United States
4038 Posts |
The "crop" does look pretty good, but the forum software is downsizing it so it isn't really 100% unless you click on it. I took a crop of the crop in order to bring it down in size enough that the forum should present it at 100%:  |
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Pillar of the Community
United States
9395 Posts |
Just for comparison, here's a 1000% crop of a 10X image of a small AF test target that goes up to element 9-3 (645 lp/mm). This was taken with the 10X/0.28 Mitutoyo objective and the Thorlabs ITL200 tube lens:  It's not clear how much of the fuzziness is caused by diffraction or aberrations from the Mitutoyo itself, vibrations, aberrations from the tube lens (which is rated for Plan Fluor objectives, not Plan APOs), debayering, etc. The Mitutoyo is supposed to resolve 1.0 micron when everything is perfect. The line spacing of the 9-3 group is about 1.55 microns and is clearly resolved. It's too bad the test chart doesn't go down to group 10-1, which would have roughly 1 micron line spacing. |
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Pillar of the Community
2087 Posts |
That re-post of the shot by rmpsrmps is much more like what I see on my screen(s). For future reference do I need to crop smaller area's for posting?
I am tempted to link two bellows together to see what can be achieved however I would expect even greater deterioration in the images
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Pillar of the Community
United States
9395 Posts |
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That re-post of the shot by rmpsrmps is much more like what I see on my screen(s). For future reference do I need to crop smaller area's for posting?
One possibility would be to enlarge the image (using something like photoshop "nearest neighbor" mode) so each pixel is clearly visible. That way, if the forum software resizes the image, you can still see each pixel. |
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Pillar of the Community
2087 Posts |
I linked two bellows together as shown in the next photo.  Please note I was using a wide angle lens so the above picture does suffer from some distortion. I wasn't actually expecting much. However I should have been more optimistic. As I noted at the beginning at this thread I had noticed in some machine vision settings that considerable extension was being used. I had to switch to the the MFT camera (to use the sony I would have had to convert the top bellows back to Minolta SR mount) To check the magnification I had to use a microscope calibration slide. It was hard to find the "ruler" so I changed technique from previous shots. To locate the ruler I placed it over an easily identifiable feature on the €10.00 note:  That established with the extension I had assembled the rig was at 9.61X: I then moved the note to get a somewhat comparable( to the earlier shots) field of view:   Despite the diffraction I believe the shot shows there is potential to seriously use the SK 40/2.8 at this magnification. Later today I will try a coin and produce a stacked image. |
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Pillar of the Community
2087 Posts |
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Pillar of the Community
United States
4038 Posts |
Hmm, I've never seen the watermarks on my images from Helicon. Looks like it is not recognizing your license key. If you re-install the key, does it still do this?
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Pillar of the Community
2087 Posts |
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I've never seen the watermarks on my images from Helicon. The problem started just after the last up date. I think I have found the issue,or at least I know how to avoid it. It only seems to occur when I use the bottom right save button: This screen shot with my editing should make it clear where the problem is originating from:  Edited by austrokiwi
08/05/2016 11:23 am
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Pillar of the Community
2087 Posts |
A better stack with diffusion:  |
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Pillar of the Community
United States
4038 Posts |
The last one is much better.
I avoid upgrading software at all costs. Once I get something that works, that's what I use, unless there is some VERY compelling reason for me to change. Most every software update I've done has caused more problems than benefit from the upgrade.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Pillar of the Community
United States
9395 Posts |
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My subscription has about 30 days to run.. at which point I will probably switch to Zerene.
Helicon's yearly? subscription fees were the main reason I switched to Zerene Stacker after the first yearly subscription ran out. I paid once and downloaded Zerene, and have been using it ever since without paying anything more. I don't run all that many stacks, or use any advanced Helicon features, so it didn't seem worth it to continue paying every year. Zerene seems to work fine for what I do (as did Helicon). Quote:
Most every software update I've done has caused more problems than benefit from the upgrade. BTW, I'm wondering what the upcoming Windows 10 anniversary edition update is going to break? I suppose I'll find out sometime in the next few weeks, whenever it decides to install itself on my machines, probably at the most inconvenient time. |
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Pillar of the Community
2087 Posts |
Quote:
BTW, I'm wondering what the upcoming Windows 10 anniversary edition update is going to break? I suppose I'll find out sometime in the next few weeks, whenever it decides to install itself on my machines, probably at the most inconvenient time That has me scared... Microsoft has turned into a tyrannical organization... they tell you what you will have and when you will have it with no concern for the customers actual needs. I wonder what sort of "tea" one would have to thow into the sea to make the point to MS executives |
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Pillar of the Community
United States
4038 Posts |
You guys realize you can turn software updates "off", right? You don't have to accept MS tyranny. I've had them turned off since I first got XP.
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Replies: 75 / Views: 10,217 |
First Page
Posted 08/04/2016 11:29 pm
