Vickers M17 refurb' & modification

Everything relating to microscopy hardware: Objectives, eyepieces, lamps and more.
Message
Author
Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Vickers M17 refurb' & modification

#1 Post by Chris Dee » Mon Mar 30, 2020 8:29 pm

I took a chance on the Vickers M17 pictured below, it had obviously been well used and would likely need some effort to bring it back to working order. I won it for a reasonable £170. The Vickers M17 was made in England and produced between the mid 1970's and early 80's. The design was a modular one available in various combinations of brightfield, incidental, phase contrast, polarization, DIC and florescence. This brightfield trinocular came with its proprietary 35mm film photography column, five Microplan achromatic objectives and 100w halogen kohler illumination. I was surprised when the delivery arrived on a pallet. Until I unwrapped it and lifted it off.. Heavy!

Image

First impressions, built like a tank. To my surprise everything moved freely and nothing was missing. Judging by the accumulation of dust it had been retired to storage uncovered for many years. After a good clean I began checking things over, both the coarse/fine focusing knobs operated smoothly with no sign of vertical stutter or binding. The x/y stage controls moved very freely, too freely, and had long since lost any damping and lubrication. A close examination of the condenser, objectives, and head unit showed no delamination or fungus, only one problem, a cracked leaf spring on the flip-top condenser which hindered secure holding of the top lens against the limit stop when swung in. Even the halogen lamp and control unit worked, and no seized controls on the lamp unit. After more dismantling, cleaning and testing It became obvious the engineering of the unit was top-notch and despite its age and long working life none of the control mechanisms had any slop or displacement.

I managed to find a PDF of the manual, specifications and a Vickers price list. This unit in its current configuration was over five thousand pounds in 1978. It dawned on me I'd landed on my feet with this one.

Plan of action. I want LED illumination but without damaging the halogen unit so it can be reversed if required. The stage has wear marks from usage and needs refinishing and a full clean/re-lube of controls/bearings. The condenser has no filter tray so something will have to be made. The illumination optics needed a little cleaning. Nothing wrong with focus mechanism (sealed behind bellows) don't mess with it. The photo tube needs modifying for use with projection eyepieces and a DSLR.

First up the condenser. This is a dry flip-top aromatic with a max NA of 90, unusually (to me) the iris diaphragm is sandwiched between 2 lenses internally and adjusted by a collar at the base. I made a replacement leaf spring from a 0.3mm feeler gauge (oh the joys of drilling spring steel) and a 3D printed attachment produced for the base of the condenser which has a steel ring embedded within it. This allowed the use of small magnets to hold diy 3D printed filters, held lightly they are quick to change and rotate freely.

Image

The removable turret needed no work and is impressive in both quality and weight. There are 2 holes in it's periphery for each objective which via an internal mechanism allow small lateral adjustments to be made with a small allen key to ensure each objective is concentric.

Image

The original lamp housing could be split into 2 halves after the removal of 3 screws. Using the original I designed a 3D printed replacement which incorporates a heavy heatsink and clamps for a Cree XHP50 5k LED (12v, 19W max), and a sliding shutter for the re-used diffusion glass of the original. Care was taken to ensure the positioning and distance of the LED is identical to the original lamp filament, as is the diffusion filter. Some testing showed the XHP50 was undesirable, uneven phosphorous distribution caused blotchy colour spots visible when focussing the lamp, the four segments of the LED's 5mm die construction also clearly visible. The last photo below shows its replacement (in badly brushed blackout paint), a XHP35 (12v 12W max), this is a single die LED and 3.5mm vs the 5mm of the XHP50. This very closely matches the size of the original halogen filament and exhibits none of the uneven colour distribution or segments of the XHP50. I tried hard to get an XHP35 HI which has no dome lens and designed for use behind secondary optics, but the Coronavirus situation has limited supply severely. I've got one on back-order but may take some time.

Image

Modifying the Photo tube for use with projection eyepieces and a DSLR was fairly simple. One of the existing units of the Vickers photo system incorporated a shutter mechanism and had an original dovetail flange. Rather than use a weak 3D printed dovetail adapter I removed the shutter mechanism guts and made the DSLR adapter to fit inside that. Point of note to experimenters printing microscope adapters, cheaply available M42-DSLR adapter rings are easily glued into a recess and far more durable than 3D printed bayonet mounts. The support arm and base of the photo column have light traps incorporated so it was simple to 3D print 2 intermediate tubes to accommodate the different focal lengths of the two projection eyepieces I use (more on that next).

Image

On the subject of projection eyepieces and the flange step to sensor distance.. I've read various figures stated for Olympus NFK 125 LD eyepieces from 125mm to 150mm (the distance between the step on the eyepiece which rests against the photo tube, and the cameras sensor). My findings are very different. The photo tube base on both my microscopes are par-focal with the main head eyepieces (if you place the LH binocular eyepiece in the photo tube you see the same as through the head eyepieces), in this situation the best flange to sensor distance for my NFK eyepiece is 165mm to be accurately par-focal with the camera. I've tested this extensively. Below are the two projection eyepieces I use, one is an unbranded 2.5x which has a slightly longer par-focal distance of 175mm, hence the need for 2 different length intermediate tubes for the photo column. This unbranded one is a mystery, its performance is very good, if anyone has information on it please post.

Image

Printed a control box which houses a cheap PWM motor controller. I replaced the linear 100k potentiometer with a logarithmic one to give more control at lower illumination levels and added a 32k series resistor which limits the full travel of the pot to 700mA (8.4W @ 12v). This unit operates between 13 and 22kHz along this range. Edit: 31-3-20. After editing a video today I discovered faint strobe lines present, my initial tests of this PWM driver missed them, my apologies. I don't recommend you use this driver for your own projects. since my interest is mainly video I plan on making a flash system using a half mirror as and when I need one.

Image

The stage was the biggest part of the refurb. After fully dismantling the stage and controls they were degreased and cleaned. The bearings and the retainers were thankfully undamaged. The control column had a small amount of corrosion on the friction spring washers which was easily cleaned off. The stage itself was stripped and any pits filled with epoxy, 3 fine grades of wet abrasive paper on a thick glass sheet was used to bring the surface flat, followed by 4 light coats of Simoniz satin black tough paint, how durable this is remains to be seen but so far is working well. Lubrication. The XY stage roller bearings and rack were lubricated lightly with Aeroshell 7 grease, this is a synthetic base grease with low volatility used for aviation instruments, I happen to have some, so why not go OTT ;) As for damping grease for use in the control shaft I ordered the only reasonably priced one on eBay, Chinese no-brand in a white tub and blue lid (item number 163864821406). To my surprise the grease is spot-on, it appears to be synthetic and has just the right amount of viscosity and stickiness for the job, it would not surprise me if this is the same grease used in most china-scopes today. How well this remains effective is anyone guess, but I suspect it will outlive me. Here are a couple of pics of the completed scope, the objectives are not the original Microplan ones except the 4x which I found superior to the Bresser one I was using previously. I hope this helps anyone who might buy one of these wonderful old Vickers M17 scopes, they are a joy to use. :)

Image
Last edited by Chris Dee on Tue Mar 31, 2020 6:41 pm, edited 1 time in total.

Hobbyst46
Posts: 2705
Joined: Mon Aug 21, 2017 9:02 pm

Re: Vickers M17 refurb' & modification

#2 Post by Hobbyst46 » Mon Mar 30, 2020 8:56 pm

Wow, what a magnificent project and results!

1. What is wrong with the original halogen lamp ? it seems to be too far from the stage to cause unwanted heating of slides ?

2. About the objectives: I recognize Zeiss West Neofluar Ph2 16X/0.40 (I own a similar one), Zeiss Jena objective and others. You did not mention the eyepieces but one photo eyepiece is Olympus. How do they all work together (parfocality, corrections etc) ? does the scope include a phase contrast condenser ?
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MichaelG.
Posts: 2052
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Vickers M17 refurb' & modification

#3 Post by MichaelG. » Mon Mar 30, 2020 9:14 pm

Chris Dee wrote:
Mon Mar 30, 2020 8:29 pm
I took a chance on the Vickers M17 pictured below […]

On the subject of projection eyepieces and the flange step to sensor distance.. I've read various figures stated for Olympus NFK 125 LD eyepieces from 125mm to 150mm (the distance between the step on the eyepiece which rests against the photo tube, and the cameras sensor). My findings are very different. The photo tube base on both my microscopes are par-focal with the main head eyepieces (if you place the LH binocular eyepiece in the photo tube you see the same as through the head eyepieces), in this situation the best flange to sensor distance for my NFK eyepiece is 165mm to be accurately par-focal with the camera. I've tested this extensively
Very nice too, Chris ... it looks a beauty.

Regarding the NFK ... 125mm is obviously the ‘right’ number, because it’s written on the eyepiece
BUT, that’s for an Olympus microscope and an OM camera body
I suspect that if you add up all the relevant numbers, you will find an explanation for why 165mm works for you.

MichaelG.

.
P.S.There are some brief notes about the M17 included here:
http://www.quekett.org/wp-content/uploa ... Part-2.pdf
Last edited by MichaelG. on Mon Mar 30, 2020 9:38 pm, edited 1 time in total.
Too many 'projects'

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#4 Post by Chris Dee » Mon Mar 30, 2020 9:28 pm

Thanks Hobbyst. The simple reason for LED illumination over halogen is I prefer it. Not sure if it is my ageing eyes but I find it easier to see fine details under LED illumination (the replacement XHP35 is 6K btw, I forgot to mention it). The main eyepieces are Vickers 10x WF Comp (compensating) ones which have a 20mm field of view. Both the photo eyepieces work well with the objectives and are par-focal when used with the appropriate intermediate tube I made for each projection eyepiece, physical height (and par-focal control) of the camera is governed by these tubes and also there is an adjustable stop collar which can be set. Any lateral adjustment needed is facilitated by a two grub screws located on the bottom and support photo tube dovetail mount. This unit does not have a phase contrast condenser, they were available at the time of production but I've not seen any used ones online, or any of the DIC attachments, not that I ever intend to go that route. Sorry for any omissions in the write-up.
Last edited by Chris Dee on Mon Mar 30, 2020 9:42 pm, edited 1 time in total.

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#5 Post by Chris Dee » Mon Mar 30, 2020 9:40 pm

MichaelG. wrote:
Mon Mar 30, 2020 9:14 pm
Chris Dee wrote:
Mon Mar 30, 2020 8:29 pm
I took a chance on the Vickers M17 pictured below […]

On the subject of projection eyepieces and the flange step to sensor distance.. I've read various figures stated for Olympus NFK 125 LD eyepieces from 125mm to 150mm (the distance between the step on the eyepiece which rests against the photo tube, and the cameras sensor). My findings are very different. The photo tube base on both my microscopes are par-focal with the main head eyepieces (if you place the LH binocular eyepiece in the photo tube you see the same as through the head eyepieces), in this situation the best flange to sensor distance for my NFK eyepiece is 165mm to be accurately par-focal with the camera. I've tested this extensively
Very nice too, Chris ... it looks a beauty.

Regarding the NFK ... 125mm is obviously the ‘right’ number, because it’s written on the eyepiece
BUT, that’s for an Olympus microscope and an OM camera body
I suspect that if you add up all the relevant numbers, you will find an explanation for why 165mm works for you.

MichaelG.
High Michael I really enjoyed the work, thanks. The odd thing about this flange to sensor/film distance thing is the Olympus OM film mount is only 2mm deeper than the Canon EF mount, the numbers don't add up. I strongly suspect the 125 on these eyepieces is very specific to the Olympus photo tube system and does not refer to the distance from the step on the eyepiece.

MichaelG.
Posts: 2052
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Vickers M17 refurb' & modification

#6 Post by MichaelG. » Mon Mar 30, 2020 9:58 pm

Chris Dee wrote:
Mon Mar 30, 2020 9:40 pm
High Michael I really enjoyed the work, thanks. The odd thing about this flange to sensor/film distance thing is the Olympus OM film mount is only 2mm deeper than the Canon EF mount, the numbers don't add up. I strongly suspect the 125 on these eyepieces is very specific to the Olympus photo tube system and does not refer to the distance from the step on the eyepiece.
You are probably right, Chris ... I also seem to recall that the Vickers primary image might be at a different depth in the tube, so the visual eyepieces are not readily interchangeable with Olympus.

More if I can find anything.
... I presume you are aware of Alan Wood’s page:
http://www.alanwood.net/photography/oly ... ieces.html

MichaelG.
Too many 'projects'

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#7 Post by Chris Dee » Mon Mar 30, 2020 10:09 pm

Yes I read Alans page, likewise it seems there is no one definitive measurement when used in other photo tube systems other than Olympus's own.

Scarodactyl
Posts: 825
Joined: Sat Mar 03, 2018 9:09 pm

Re: Vickers M17 refurb' & modification

#8 Post by Scarodactyl » Mon Mar 30, 2020 11:48 pm

This is an excellent project! I am especially impressed with the 3D printed parts--beautiful as well as functional.
I've seen a 'photo kpl' eyepiece before, photographed on this page by Enrico Savazzi http://www.savazzi.net/photography/zeissadapter.html But he didn't know the maker or any other information either, he just found it to be incompatible with his Zeiss objectives. It looks similar but maybe not identical to yours.
Not to state the obvious, but of course any photo eyepiece can be made parfocal on a given system--if it's placed higher or lower it just changes the magnification and parfocal distance to the camera (while also affecting image quality to some extent). Not sure if that's what's going on here though.

apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#9 Post by apochronaut » Tue Mar 31, 2020 12:02 am

A beautiful microscope, lovingly restored and upgraded somewhat. It even has a centering nosepiece. wow. Remarkable that many of it's brethren and others from other factories, ended up in dumpsters. Excellent work.

User avatar
daruosha
Posts: 273
Joined: Wed Oct 23, 2019 7:10 am
Location: Tehran, Iran

Re: Vickers M17 refurb' & modification

#10 Post by daruosha » Tue Mar 31, 2020 7:52 am

Inspiring work Chris. 3D printed parts, modernized illumination, etc... makes it even better than its original configuration. Well done.
Daruosh.

Roldorf
Posts: 479
Joined: Tue Apr 23, 2019 6:58 pm
Location: Northern Germany

Re: Vickers M17 refurb' & modification

#11 Post by Roldorf » Tue Mar 31, 2020 11:20 am

Very nice, well done. You should put a side by side comparison photo, before and after. It's a pain having to scroll up and down to see the differences. :D
Location: Northern Germany

Unknown Brand: Optika SFX 91: Bresser Science Infinity: Canon 4000d
ImageImage

MicroBob
Posts: 2098
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers M17 refurb' & modification

#12 Post by MicroBob » Tue Mar 31, 2020 2:53 pm

Hi Chris,
nice restoration of an interesting microscope! Good that you got rid of the nicotin beige components too. This is a fairly rare microscope with probably few sold units outside of GB and even fewer surviving stands. The objectives turn up frequently on ebay UK so it won't be a problem to add more.

Bob

apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#13 Post by apochronaut » Tue Mar 31, 2020 3:47 pm

The most common Cooke-Baker and the later branded Vickers objectives, were the Microplans. That's their terminology for what some call Semi-Plan or Neoplan. The common eyepieces used with them were the Kellner 18mm f.o.v. It is a bit odd that the scope had the Compens eyepieces. Normally, those were mated with the quite uncommon Vickers fluorites or Apochromats. It's even odder that they are well corrected for the set up of alternate objectives I see in the nosepiece. I have a set of those and they are superb eyepieces, however with most of the optics I have trialled them with, the compensation is good only to about 90% of the f.o.v., where it then gets to be too much and creates a fine level of ca around the periphery. I found that they work pretty well with AO apochromats, depending on the era they were made in; less so with B & L apochromats or Zeiss.

Are you getting edge to edge correction for ca with those?

MichaelG.
Posts: 2052
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Vickers M17 refurb' & modification

#14 Post by MichaelG. » Tue Mar 31, 2020 3:49 pm

Chris ... I forgot to thank you for the ebay reference for that damping grease

Recommendations like that are very helpful.

MichaelG.

.
Incidentally, I have [thanks to Google] just translated the Chinese characters on the lid
... It does indeed say Damping Grease
Too many 'projects'

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#15 Post by Chris Dee » Tue Mar 31, 2020 7:18 pm

Thanks everyone for the kind words and encouragement. Sadly I have today discovered PWM generated strobe lines in a video I was editing, they are fine but noticeable. My initial testing was obviously not thorough enough, my apologies. I have edited the post to reflect this, back to the bench power supply (and the fan noise) for the time being until I come up with another solution. I'll keep you posted on developments.
Scarodactyl wrote:
Mon Mar 30, 2020 11:48 pm
This is an excellent project! I am especially impressed with the 3D printed parts--beautiful as well as functional.
I've seen a 'photo kpl' eyepiece before, photographed on this page by Enrico Savazzi http://www.savazzi.net/photography/zeissadapter.html But he didn't know the maker or any other information either, he just found it to be incompatible with his Zeiss objectives. It looks similar but maybe not identical to yours.
Thanks Scarodactyl, there does appear to be some similarity between that eyepiece and my own, however I've not noticed any adverse chromatic or spherical aberrations in my set up, so suspect it is not the same, or the test conditions were different. The 3D prints were made on a budget Creality CR-10 Mini, unmodified and has proved to be a good workhorse and low maintenance.
apochronaut wrote:
Tue Mar 31, 2020 3:47 pm
The most common Cooke-Baker and the later branded Vickers objectives, were the Microplans. That's their terminology for what some call Semi-Plan or Neoplan. The common eyepieces used with them were the Kellner 18mm f.o.v. It is a bit odd that the scope had the Compens eyepieces. Normally, those were mated with the quite uncommon Vickers fluorites or Apochromats. It's even odder that they are well corrected for the set up of alternate objectives I see in the nosepiece. I have a set of those and they are superb eyepieces, however with most of the optics I have trialled them with, the compensation is good only to about 90% of the f.o.v., where it then gets to be too much and creates a fine level of ca around the periphery. I found that they work pretty well with AO apochromats, depending on the era they were made in; less so with B & L apochromats or Zeiss.

Are you getting edge to edge correction for ca with those?
Below are excepts from the advertising brochure and Vickers own price list, I can only presume these eyepieces were made available across the various brightfield configurations of this scope. There also appears to be 2 body variants of the Microplan achromats, one with a paint in the lower barrel recess, another with a single coloured band at the top, mine are the latter. Having viewed several slides after reading your post I can confirm no sign of the peripheral CA you mention, the objectives tested were: Zeiss Neofluar 16x Ph2, Neofluar 40x, Zeiss Jena 25x APO, Zeiss Jena 6.3x APO. Which microscope did you test the eyepieces and objectives in apochronaut?
Attachments
Eyepieces.jpg
Eyepieces.jpg (136.37 KiB) Viewed 858 times
Last edited by Chris Dee on Tue Mar 31, 2020 7:43 pm, edited 1 time in total.

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#16 Post by Chris Dee » Tue Mar 31, 2020 7:29 pm

MichaelG. wrote:
Tue Mar 31, 2020 3:49 pm
Chris ... I forgot to thank you for the ebay reference for that damping grease

Recommendations like that are very helpful.

MichaelG.

.
Incidentally, I have [thanks to Google] just translated the Chinese characters on the lid
... It does indeed say Damping Grease
The wonders of modern technology that completely slip my mind :lol: Thanks Michael

Hobbyst46
Posts: 2705
Joined: Mon Aug 21, 2017 9:02 pm

Re: Vickers M17 refurb' & modification

#17 Post by Hobbyst46 » Tue Mar 31, 2020 7:36 pm

Chris Dee wrote:
Tue Mar 31, 2020 7:18 pm
...Sadly I have today discovered PWM generated strobe lines in a video I was editing, they are fine but noticeable. My initial testing was obviously not thorough enough, my apologies. I have edited the post to reflect this, back to the bench power supply (and the fan noise) for the time being until I come up with another solution. I'll keep you posted on developments...
When the PWM frequency is too low, rapid (short-duration) exposures can yield banding. I can hardly imagine that this is the case for a 600kHz PWM, though. My 21kHz PWM yields banding, but only when the exposure speed is 250-300 or higher (~4ms or shorter durations).

Also, your Zeiss 16X objective is I think "Neofluar" ("Fluotar" is Leitz terminology). Zeiss (West) 16X/0.40 Ph2 - a very useful objective. A touch of luck, that such objective gives CA-free images with a non-Zeiss eyepiece.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#18 Post by Chris Dee » Tue Mar 31, 2020 7:46 pm

Corrected, thanks for pointing that out. Need to take a break from searching eBay for fluorite objectives, and lay off the wine when posting ;)
Hobbyst46 wrote:
Tue Mar 31, 2020 7:36 pm
Chris Dee wrote:
Tue Mar 31, 2020 7:18 pm
...Sadly I have today discovered PWM generated strobe lines in a video I was editing -snip-
When the PWM frequency is too low, rapid (short-duration) exposures can yield banding. I can hardly imagine that this is the case for a 600kHz PWM, though. My 21kHz PWM yields banding, but only when the exposure speed is 250-300 or higher (~4ms or shorter durations).

Also, your Zeiss 16X objective is I think "Neofluar" ("Fluotar" is Leitz terminology). Zeiss (West) 16X/0.40 Ph2 - a very useful objective. A touch of luck, that such objective gives CA-free images with a non-Zeiss eyepiece.
It tried the eyepieces from my china trinocular scope in the M17 with these objectives and the image is noticeably poorer with CA and lower contrast. Interestingly when these same Neofluar objectives are used in the china trinocular the image does not exhibit the low contrast, but does have a small amount of CA. The APO objectives seem happy in both combinations.

MicroBob
Posts: 2098
Joined: Sun Dec 25, 2016 9:11 am
Location: Northern Germany

Re: Vickers M17 refurb' & modification

#19 Post by MicroBob » Tue Mar 31, 2020 8:17 pm

This is a Zeiss Jena Planapochromat 25....C where "C" means it is intended to be used with a correction eyepiece. This is a very late (and rare) 160mm objective, it has to date from shortly before the appearance of the CF 250 infinity objective series.
Zeiss Jena and Zeiss West were close in the chromatic corrections of their eyepieces so it is no wonder that four of the objectives work well together. The intermediate image is 13mm down the tube with Zeiss Jena so a certain deviation from the 10mm of Zeiss West. In practice I use them together with good results. I have no Idea what to expect from the eyepieces though. But if it works it is fine! Testing with an objectmicrometer will prove how good a match this is.

Bob

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#20 Post by Chris Dee » Tue Mar 31, 2020 8:41 pm

Thanks for the info' on the 25x objective Bob, I had no clue about its heritage. Its my favourite of the objectives I own, not only for its clarity but 25x is such a useful magnification for many species of pond life observations. This possibly confirms my thoughts that the eyepieces in my china trinocular are compensating ones despite having no markings to indicate it. I have a objectmicrometer slide and use it when testing optics, though I prefer to make final judgements on live samples. Like you say, if it works its good.

apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#21 Post by apochronaut » Tue Mar 31, 2020 9:19 pm

Chris Dee wrote:
Tue Mar 31, 2020 7:18 pm
Thanks everyone for the kind words and encouragement. Sadly I have today discovered PWM generated strobe lines in a video I was editing, they are fine but noticeable. My initial testing was obviously not thorough enough, my apologies. I have edited the post to reflect this, back to the bench power supply (and the fan noise) for the time being until I come up with another solution. I'll keep you posted on developments.
Scarodactyl wrote:
Mon Mar 30, 2020 11:48 pm
This is an excellent project! I am especially impressed with the 3D printed parts--beautiful as well as functional.
I've seen a 'photo kpl' eyepiece before, photographed on this page by Enrico Savazzi http://www.savazzi.net/photography/zeissadapter.html But he didn't know the maker or any other information either, he just found it to be incompatible with his Zeiss objectives. It looks similar but maybe not identical to yours.
Thanks Scarodactyl, there does appear to be some similarity between that eyepiece and my own, however I've not noticed any adverse chromatic or spherical aberrations in my set up, so suspect it is not the same, or the test conditions were different. The 3D prints were made on a budget Creality CR-10 Mini, unmodified and has proved to be a good workhorse and low maintenance.
apochronaut wrote:
Tue Mar 31, 2020 3:47 pm
The most common Cooke-Baker and the later branded Vickers objectives, were the Microplans. That's their terminology for what some call Semi-Plan or Neoplan. The common eyepieces used with them were the Kellner 18mm f.o.v. It is a bit odd that the scope had the Compens eyepieces. Normally, those were mated with the quite uncommon Vickers fluorites or Apochromats. It's even odder that they are well corrected for the set up of alternate objectives I see in the nosepiece. I have a set of those and they are superb eyepieces, however with most of the optics I have trialled them with, the compensation is good only to about 90% of the f.o.v., where it then gets to be too much and creates a fine level of ca around the periphery. I found that they work pretty well with AO apochromats, depending on the era they were made in; less so with B & L apochromats or Zeiss.

Are you getting edge to edge correction for ca with those?
Below are excepts from the advertising brochure and Vickers own price list, I can only presume these eyepieces were made available across the various brightfield configurations of this scope. There also appears to be 2 body variants of the Microplan achromats, one with a paint in the lower barrel recess, another with a single coloured band at the top, mine are the latter. Having viewed several slides after reading your post I can confirm no sign of the peripheral CA you mention, the objectives tested were: Zeiss Neofluar 16x Ph2, Neofluar 40x, Zeiss Jena 25x APO, Zeiss Jena 6.3x APO. Which microscope did you test the eyepieces and objectives in apochronaut?
About a year ago I got a bee on my bonehead regarding photo eyepieces and their compatibility with certain objectives and systems from other mfg. I set up a test microscope stand with a graduated drawtube and trialled various eyepieces and objective combinations , visually and photographically.
Vickers made two versions of 10X compens eyepieces. One has a fairly small eyelens, similar to many others made by many mfg., so marked and the other has a quite broad eyelens, probably about 20mm in diameter. Other than that, the eyepieces look quite similar and the version I have with the wide eyelens is marked the same as the other version. It does not have a W.F. designation for instance but it does produce a wide field. I have not measured it but it would be around 20mm. I included that eyepiece in my trials. I had all the data written down but it would take a while to find it now , however I committed the important details to memory. My goal was to have a personal data base covering which eyepieces worked well with which objectives for primarily photo purposes. The eyepieces ranged from 2.5X to 10X. The data ended up being quite simple. Most of the eyepieces did not work with objectives from other mfg. because most individual mfg. introduce corrections into their eyepieces to compensate for the aberrations and distortions of their objectives. Many combinations produced very obvious mismatches and in some cases the mismatch was visually difficult to detect but showed up much more obviously in a photo image. The Vickers were in the latter category. With certain productions of Spencer apochromats for instance the Vickers 10X compens performed as well visually or very close to the performance of Spencer compens eyepieces but with a wider field, they were pretty attractive as an alternative for visual microscopy. They did not do so well with B & L apochromat objectives. However, when used for photography with the Spencer objectives, there was a degree of noticeable yellow chroma towards the periphery of the image. With those objectives also, Cooke-Baker compens eyepieces did produce a small amount of yellow peripheral fringing both visually and moreso as a photo image, so it does seem that Vickers, like so many other makers may have been on a continuum of tweaking their objectives over time, with corresponding tweaks in the eyepieces. I did not find that the Vickers 10X compens worked well with any other objectives, except perhaps some older Nikons and a few unusual objectives from the past....some from the 19th century. I do have a set of Vickers Microplans and they work o.k. but that match is not really a measure of how a compens eyepiece is performing.

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#22 Post by Chris Dee » Tue Mar 31, 2020 9:58 pm

The eyelens on my Vickers eyepieces are 15.7mm diameter. There is a thin pale yellow peripheral ring at the edge of the view coverage, is this the CA you were referring to? I'd assumed this was common to all compensating eyepieces.

MichaelG.
Posts: 2052
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Vickers M17 refurb' & modification

#23 Post by MichaelG. » Tue Mar 31, 2020 10:33 pm

This discussion has prompted me to look for information specific to Vickers optics, and I’ve just found this brochure: https://groups.rifeforum.com/Files/Micr ... 204-65.pdf

First time I’ve seen that one ... and it’s rather good !!

MichaelG.
Too many 'projects'

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#24 Post by Chris Dee » Tue Mar 31, 2020 11:22 pm

Published in Apr 1965 if the number at the bottom is a date code. I also have this from the same source as well as other documents. Caused me some confusion over the NA discrepancies of my objectives until I realised it pre-dated the M17. Still a good document though, very informative.

MichaelG.
Posts: 2052
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Vickers M17 refurb' & modification

#25 Post by MichaelG. » Wed Apr 01, 2020 8:30 am

Chris Dee wrote:
Tue Mar 31, 2020 11:22 pm
Published in Apr 1965 if the number at the bottom is a date code. […]
That’s a good point, Chris

All my Vickers/CTS/Baker stuff is older than yours, I think.

MichaelG.
Too many 'projects'

apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#26 Post by apochronaut » Wed Apr 01, 2020 1:09 pm

Chris Dee wrote:
Tue Mar 31, 2020 9:58 pm
The eyelens on my Vickers eyepieces are 15.7mm diameter. There is a thin pale yellow peripheral ring at the edge of the view coverage, is this the CA you were referring to? I'd assumed this was common to all compensating eyepieces.
Actually, 15.7mm sounds about right. I just measured one with a ruler and the field lens has a rather unusual concave surface which I have not seen in any other compens eyepiece. They are marked 10X W.F. COMP but I think these are Complans or a more complex version of compensating eyepieces that include corrections for planarity as well. They aren't quite compens types because they seem to work o.k. with certain achromats.
Traditional compensating eyepieces usually have restricted fields of view, because in order to provide corrections to the field stop, they had to have a fairly narrow field stop, narrower than a contemporary huygens eyepiece for instance. The ability to provide full compensation , planarity and a wide field wasn't possible with the glass available from about 1960 backward; at least not at a price that anyone would pay for. It may have been technically possible. I've seen lots of old patents from the 1930's and 40's that were extremely optimistic ; objectives with 1.62 N.A., completely flat fields; all kinds of fancy optics but most of them never went into production due to the cost involved. Those high N.A. objectives ( Bausch & Lomb had one) required methylene iodide as an immersion fluid.
All compensating eyepieces have a thin yellow band around the field stop and so called non-compensating a thin blue band. That's because conventional eyepieces such as Huygens or Kellner slightly over correct or over compensate for some of the peripheral aberrations and compensating eyepieces undercorrect; due to the fact that in order for the objective, usually an apochromat, to correct at 3 wavelengths and as well correct for astigmatism, coma , etc. it must be overcorrected at source and then undercorrected at the eyepiece. This is why compens eyepieces don't work well with achromats. They work for the central section of the field but not for the periphery, where most of the corrections take place. That's why you will see compens eyepieces recommended with achromats for photography and not visual use. It's because the photographic frame in the older systems only took in the central section of the field, where the compens eyepieces are not overcorrecting and their slightly higher resolving power is beneficial.

apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#27 Post by apochronaut » Wed Apr 01, 2020 2:54 pm

MichaelG. wrote:
Tue Mar 31, 2020 10:33 pm
This discussion has prompted me to look for information specific to Vickers optics, and I’ve just found this brochure: https://groups.rifeforum.com/Files/Micr ... 204-65.pdf

First time I’ve seen that one ... and it’s rather good !!

MichaelG.
That's from just after the name change from Cooke-Baker to Vickers. Most of the optics offered can also be found with the Cooke-Baker name on them. Vickers, later issued a 100X 1.30 Microplan. The 50X fluorite also existed as a short barrel version. The 8X compens are a Cooke-Baker eyepiece, I'm pretty sure later discontinued by Vickers. They aren't quite compatible with other 160mm apochromats I have here; Spencer, Bausch & Lomb , Zeiss, Lomo and Koristka. Cooke-Baker also catalogued some water immersion objectives in the short barrel format 50X 1.0 and 100X 1.30. Those are achromats.
Interestingly, the catalogue only shows a Kellner 10X eyepiece as a focusing measuring type? CTS and later Cooke-Baker offered them and then later than this catalogue , Kellners seem to have been used on the photoplan; at least I have seen as many on those as the 10 and 12.5X W.F. COMP.
although this isn't a photoplan head: https://www.ebay.com/itm/Vickers-Binocu ... Swe-FU4zXp

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#28 Post by Chris Dee » Wed Apr 01, 2020 3:13 pm

Thank you apochronaut for the detailed explanation, much appreciated. The eyelens on these eyepieces is flat, the lower lens of the eyepiece is flush with the base and slightly concaved. Below is a quick video of the 16x Neofluar, and 25x Jena APO with an uncooperative subject. I tried to get footage with 40x Neofluar but the rotifer was too mobile to get anything worthwhile. The vid was shot through the unbranded 2.5x projection eyepiece without any post processing. I forgot to set the camera to evaluative metering so excuse the fluctuations. This roughly represents what I see through the eyepieces across all but the very extreme edges of the field of view, with the usual reduction in resolution from a cropped APSC sensor and projection eyepiece magnification. Still some familiarisation with the scope and tweaks needed.


apochronaut
Posts: 3220
Joined: Fri May 15, 2015 12:15 am

Re: Vickers M17 refurb' & modification

#29 Post by apochronaut » Wed Apr 01, 2020 3:44 pm

That's very nice imaging. Obviously, that photo eyepiece is pretty much spot on for those objectives. Have you tried the 10X COMP in the photo tube?

Chris Dee
Posts: 138
Joined: Mon Aug 12, 2019 1:02 pm

Re: Vickers M17 refurb' & modification

#30 Post by Chris Dee » Wed Apr 01, 2020 3:52 pm

Quick shots of the eyepieces. I did quickly try the both the binocular 10x eyepieces and the 10x graticuled adjustable-focus eyepiece (both comp) that came with the unit in the photo tube, however the crop factor was v-large and consequently low contrast with direct projection. Possibly something to experiment with in the future using a 50mm camera lens as a relay. I've had some decent results from previous tests using a Yashica 50mm f:1.9 lens, but not tried on this microscope.
Attachments
Eyepieces.jpg
Eyepieces.jpg (120.54 KiB) Viewed 739 times

Post Reply