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4/0.1 microscope objective

 
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NikonUser



Joined: 04 Sep 2008
Posts: 2560
Location: southern New Brunswick, Canada

PostPosted: Fri Jan 30, 2009 8:00 pm    Post subject: 4/0.1 microscope objective Reply with quote

Just tested the quality/usefulness of an objective that came off an old Parco scope.

Subject: male genitalia (slide mount) of a noctuid moth, Eupsilia vinulenta. This moth looks almost identical to the European "The Satellite" Eupsilia transversa.

Lens: El Cheapo 4x; 160mm bellows. 37 frames @ 0.01mm, HF stack which for some unknown reason is not giving halos.

Top: slight crop of original; original frame: 2848x4288px; this crop: 2184x3324px (and then resampled to 800px max)
Bottom: 800 px selection from the original frame (area is shaded area on top image)
Note: the width of the hair is about 0.007mm.

Assessment: even a basic, no name, 4x scope objective can give excellent results.



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NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

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rjlittlefield
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Joined: 01 Aug 2006
Posts: 19977
Location: Richland, Washington State, USA

PostPosted: Fri Jan 30, 2009 8:32 pm    Post subject: Reply with quote

This looks pretty good. I notice that the pixel-peep is at the center of the image. How far away from center does the quality hold up?

Thinking out loud... NA = 0.1 at 4X on a 160 tube corresponds to about 32 mm FL f/4. So this thing is running at right about where I usually set my Olympus 38 mm bellows lens.

--Rik
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augusthouse



Joined: 16 Sep 2006
Posts: 1195
Location: New South Wales Australia

PostPosted: Sat Jan 31, 2009 12:42 am    Post subject: Reply with quote

NU,

A smooth image!

I noted the "not giving halos" observation.

When I see something like this I have to ask the question - why are halos not there and would they be there if the background or lighting were altered or if the photographer had worn a different colour jacket on the day? Are there other factors influencing the outcome - those factors could be numerous - would be good to try and isolate some of them if possible...

This post reminds of one of the things on my to-do-list (however absurd it may at first appear - please tolerate my naive indulgence).

If we were to take an RGB image, separate the channels, export and stack the channels individually (examine/assess) and then recombine or reform an RGB image (maybe even replace the noisiest channel and reassign or simulate) would this provide any visible advantages? It's the long way 'round but I'm curious about the whole process and possible outcome.

Prokudin-Gorskii (http://www.loc.gov/exhibits/empire/making.html)

Also have some detailed notes from Richard Lynch's books - 'The Hidden Power of Photoshop' and 'The Adobe Photoshop Layers Book' - not the you beaut' WOW book by another author - haven't read that one.

The Hubble Telescope keeps popping into my head also - not literally.
http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/eagle.php

http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/rgb.php

I am yet to stack a monochrome image - is there a discernable difference in the outcome as opposed to the same image stacked in full colour?

Craig
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rjlittlefield
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Joined: 01 Aug 2006
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Location: Richland, Washington State, USA

PostPosted: Sat Jan 31, 2009 1:31 am    Post subject: Reply with quote

Quote:
If we were to take an RGB image, separate the channels, export and stack the channels individually (examine/assess) and then recombine or reform an RGB image (maybe even replace the noisiest channel and reassign or simulate) would this provide any visible advantages? It's the long way 'round but I'm curious about the whole process and possible outcome.

I'm not sure they match what you have in mind, but experiments along these lines were done somewhat inadvertently during recent development of the pyramid methods.

The original paper on "Exposure Fusion" described what was essentially a single-channel algorithm. The authors of that paper commented in passing that "For dealing with color images, we have found that carrying out the blending each color channel separately produces good results." Presumably this was correct in their experiments, which focused on HDR fusion.

But when codes based on separated channels were tested for focus stacking, the output images frequently developed strange localized color shifts, rather like those in the flowing water image on the Prokudin-Gorskii site that you link.

The cause of those color shifts was eventually tracked down to the fact that pixel values were being accumulated differently in the various channels, so that RGB proportions at a pixel in the reassembled image did not necessarily correspond to the RGB proportions of any pixel in the source images.

In other words, separating the channels caused the colors to shift by optimizing each channel independently.

The problem was greatly reduced (at least in TuFuse and CombineZP) by tweaking the algorithm to do the same operations on all three channels together, instead of potentially different operations on each channel separately. Even with the tweaks, there can still be color shifts with deep stacks due to various nonlinearities, but the problem is about 10X less than with separated channels.

--Rik
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NikonUser



Joined: 04 Sep 2008
Posts: 2560
Location: southern New Brunswick, Canada

PostPosted: Sat Jan 31, 2009 1:11 pm    Post subject: Reply with quote

rjlittlefield wrote:
This looks pretty good. I notice that the pixel-peep is at the center of the image. How far away from center does the quality hold up?
--Rik

I have tracked down this lens. It's a Meiji S.Flat Achromat 4x/0.1 NA. One of the lenses on their discontinued TM490 binocular microscopes.

I chose that first selection because I wanted to show how well the lens performed on those tiny hairs.

Current image. Inset image is full frame stack. Large image is 800px selection from the extreme bottom right of the valve; as you see quite close to the edge of the original frame. My take is that the quality holds up well.


_________________
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

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Olympus microscope and objectives
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rjlittlefield
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Joined: 01 Aug 2006
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Location: Richland, Washington State, USA

PostPosted: Sat Jan 31, 2009 1:22 pm    Post subject: Reply with quote

Yes, that looks great! Definitely a good substitute for the Olympus bellows macro lens in this magnification range.

--Rik
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lauriek
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Joined: 25 Nov 2007
Posts: 2404
Location: South East UK

PostPosted: Sun Feb 01, 2009 11:20 am    Post subject: Reply with quote

Thanks for the info NU, I've been on the lookout for a cheaper alternative to the Oly 38 for a while now!
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NikonUser



Joined: 04 Sep 2008
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Location: southern New Brunswick, Canada

PostPosted: Sun Feb 01, 2009 2:28 pm    Post subject: Reply with quote

Laurie:
This is the lens. I suspect you can pick up a similar lens quite cheaply on ebay.
The brushed aluminium part unscrews allowing for an even longer WD.
The actual lens finishes at about the level of the yellow line, so even with the aluminium part removed you still get a bit of a lens shade.


_________________
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives
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mgoodm3



Joined: 08 Sep 2008
Posts: 273
Location: Southern OR

PostPosted: Sun Feb 01, 2009 2:43 pm    Post subject: Reply with quote

I found that taking off the end of the objective (like the brushed portion on yours) helps improve the images on my cheap 4x. With it on, I notice that there is quite a lot more flare in the images. The inside of the cap on mine is brushed brash and kinda shiny. Taking it off removes that source of flare and improves the image.
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Cyclops



Joined: 05 Aug 2006
Posts: 2968
Location: North East of England

PostPosted: Mon Feb 02, 2009 10:21 am    Post subject: Reply with quote

Hmmm,thanks to a kind member on here I have one like that! Heaven knows how connect it to my canon tho!
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mgoodm3



Joined: 08 Sep 2008
Posts: 273
Location: Southern OR

PostPosted: Mon Feb 02, 2009 11:32 am    Post subject: Reply with quote

The easiest way to connect a cheap objective (RMS mount) is to get a RMS to TMount adapter (Edmund optics has these) and a Tmount adapter for your camera.
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NikonUser



Joined: 04 Sep 2008
Posts: 2560
Location: southern New Brunswick, Canada

PostPosted: Mon Feb 02, 2009 11:57 am    Post subject: Reply with quote

Removing the end of the lens barrel sounds a good idea; perhaps replace it with a black paper tube.

These lenses are designed to work at about 160mm from the sesnsor (either your eye or the camera's sensor); some may work best at 220mm. Thus not sure how they would perform if fiitted directly (via T-mount and RMS to T-mount adapter). The photos I took had the lens mounted on 160mm of total extension (bellows + mounts).
_________________
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives
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Charles Krebs



Joined: 01 Aug 2006
Posts: 5805
Location: Issaquah, WA USA

PostPosted: Mon Feb 02, 2009 12:30 pm    Post subject: Reply with quote

Larry,
Quote:
Hmmm,thanks to a kind member on here I have one like that! Heaven knows how connect it to my canon tho!

Must be real nice guy! Wink

Get yourself two sets of those cheap Chinese extension tubes (Like eBay 380101374486), add a cheap body cap to the front with a hole drilled in it, and attach the objective.

Or... get a piece of plastic plumbing tube (about 105mm long), afix it to a drilled out body cap (or better yet a cheap EOS T-mount). Put a flat disk with a hole in it up front and attach objective. (Paint the inside flat black!)

You seem to like playing around with "fun" combinations, so I really think you would find a lot to do with those cheap extension tubes. (Although there is no linkage to the camera electronics, so your 100mm macro would be fully manual at max aperture).
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mgoodm3



Joined: 08 Sep 2008
Posts: 273
Location: Southern OR

PostPosted: Mon Feb 02, 2009 3:22 pm    Post subject: Reply with quote

The objective won't work well mounted directly to a body. Too little extension and you have either too small of an image circle or horrible spherical aberration.

Use the adapters with extension either from a bellows, extension tubes. Splurge and spend $30 on 3 sets of cheap chinese extension tubes (actually pretty sturdy).

Tmount extensions can also be purchased for a little more that will work well.
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