Not All that Glitters is Gold

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

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conkar
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Post by conkar »

canonian wrote:Conny, I kinda hoped it's the other one:

Standard Achromatic Microscope Objectives -- MSO17900/100

EFL (mm): 8.2
Magnification: 20X (Long Working Distance)
NA: 0.30
Working Distance: 5.8
Specifications: DIN Type (Shoulder Height 45mm, Mechanical Tube Length 160mm)

http://datasheets.globalspec.com/ps/522 ... EB2467DEE7
Fred, in terms of WD i hope your findings are right, but for the na I hope not.

I think we have to wait and see what this JML 20X is.......

It might be a turkey or a golden goose....:roll:


Regards,

Conny arrival 9/3

g4lab
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Post by g4lab »

I spoke to someone at sunnking and he said the working distance for focusing with his eye was one to two millimeters

The optics were not surplused directly from JML but rather from
a clinical medical instruments division of Eastman Kodak. It was probably
used to gather light in some kind of spectrophotometric assay probably one
encapsulated in some kind of plastic slide.

I will shoot a snipe on the tray of thirty. If we don't win it we probably will have another similar tray made available to us.

naturephoto1
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Post by naturephoto1 »

g4lab wrote:I spoke to someone at sunnking and he said the working distance for focusing with his eye was one to two millimeters

The optics were not surplused directly from JML but rather from
a clinical medical instruments division of Eastman Kodak. It was probably
used to gather light in some kind of spectrophotometric assay probably one
encapsulated in some kind of plastic slide.

I will shoot a snipe on the tray of thirty. If we don't win it we probably will have another similar tray made available to us.
That working distance is in the range that Chris S had initially suggested. 1 to 2 mm is not much working distance to place any lighting at 20X. I'll have to think about this for myself.

Rich

Craig Gerard
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Post by Craig Gerard »

WD 1 to 2mm :( =;
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

ChrisR
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Post by ChrisR »

I know I'm labouring the point but I don't have any objective with an entrance diameter that big and a WD as short as under 2mm. Room for some optimism I think?

Tesselator
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Post by Tesselator »

naturephoto1 wrote:
NikonUser wrote:Currently a tray of 30 for sale, $15.00 for the lot at present.
If they are 'good' lenses we, as a group, may get a bargain.

http://www.ebay.com/itm/360438163254?ru ... 3D1&_rdc=1
I would be willing to share in a split lot order of these.

Rich
Careful, over $100 for shipping. ;)

naturephoto1
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Post by naturephoto1 »

Tesselator wrote:
naturephoto1 wrote:
NikonUser wrote:Currently a tray of 30 for sale, $15.00 for the lot at present.
If they are 'good' lenses we, as a group, may get a bargain.

http://www.ebay.com/itm/360438163254?ru ... 3D1&_rdc=1
I would be willing to share in a split lot order of these.

Rich
Careful, over $100 for shipping. ;)
Not sent to the US. :wink:

Rich

conkar
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Post by conkar »

Image
JML 20X treated as 160

Image

JML 20X full bellows draw

This is just a first test of the JML 20X and the images are single exposures done with a APS-C DSLR Canon EOS 7D.

I tested the objective as a finite objective and I will test it later with a 200mm tubelens to see how it works out.

I was curious about the working distance and I estimate it to be around 10-12mm.

The thread size was RMS.

Tnx Craig! :D

Regards,

Conny

canonian
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Post by canonian »

conkar wrote:... I estimate it to be around 10-12mm.
That's quite a comfortable WD ! Did you get one from the tray?
I'm very curious how it performs mounted on a tubelens.

conkar
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Post by conkar »

canonian wrote:
conkar wrote:... I estimate it to be around 10-12mm.
That's quite a comfortable WD ! Did you get one from the tray?
I'm very curious how it performs mounted on a tubelens.
No, I don't got it from the tray, this was a single one.

If a tray it's on the run to europe, I might be interested of some more.

I running a full frame test with a FF right now with the objective mounted on a 200mm tubelens. The WD seems to be to same.

I'll be back on that tomorrow. My computers are old and slow (like me :lol:) so it take some time to get a finnished stacked image.

Regards,

Conny

canonian
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Post by canonian »

conkar wrote:... so it take some time to get a finnished stacked image.
Please take your time, it's great that you are willing to investigate this turkey / golden goose chase. :)

Craig Gerard
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Post by Craig Gerard »

Conny,

Thanks for the report.

Looks encouraging, but difficult to determine the possiblity of spherical aberration from your initial images.


Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

conkar
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Post by conkar »

Image
JML 20X 200mm infinity FF

Canon EOS 5DmkII and Canon EF 200mm f/2.8L II USM as tubelens with a JML 20X microscope objective.

105 images stacked with Zerene Stacker Pmax, step size 5µm.

High res:
http://farm8.staticflickr.com/7203/6969 ... 4213_o.jpg


It's alot of dust and scratches in this worn stamp, I think I have to find a better test sample and also set it up against some ruler to find the right magnification.

I am not shure about the magnification in this last picture, when I look at the picture it seems to be more around 10X than 20X.

With the 3 tests I had done my impression is that the JML 20X is a finite objective.

Regards,

Conny

canonian
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Post by canonian »

I do not know what I'm actually looking at, it gives no visual reference and it's hard to see the quality and resolution on the sample of the worn stamp.
If you mount the JML on a tubelens, isn't it an infinite than? (I'm a bit confused :smt102 )

Craig Gerard
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Post by Craig Gerard »

Conny,

It may be worthwhile using a 'flat' sample (providing your stage is level), basically something that can be photographed with a single exposure (black on white would be good).



Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

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