Objective projection, SwiftSW350T on to camera (Canon) sensor

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Thl05
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Objective projection, SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Hello all, I have been reading and absorbing the forum for a little while, very informative !

Now I have a question :)
I have searched the forum (and elsewhere) for info on the Swift SW350T trinocular but nothing found.
Can anyone tell me about the detail of the trinocular tube on the 350T (or380T) . Is it all a one piece tube or does it break down into two (or more) bits ?

The reason I ask is that I have been playing with a Heath-Robinson affair of an objective on an old Meopta body (without the prism and eyepiece tube) projecting into a Canon 60D body which I balance on the top using three extension tube/rings and a helicoid.
It kinda works but it is precarious. (picture later if needed ! )
So, I am thinking new microscope and wondering if I can do a similar thing by attaching the dslr to the trino tube part way down (or up!), iyswim. ie removing the upper part of the trino tube that is designed to take a third eyepiece, or the eyepiece usb camera that is sold with some of the models.

I know that there are eyepiece tube adapters for dslr incorporating a (relay?)lens, available at further cost, but that could come later when I gain more experience with all the other things I need to learn (slide making to begin ! )

Thanks.
Last edited by Thl05 on Wed Jul 15, 2020 11:53 pm, edited 2 times in total.

Thl05
Posts: 14
Joined: Wed Nov 27, 2019 6:10 pm
Location: SW England

Re: Update_SwiftSW350T to camera (Canon)

Post by Thl05 »

Here is a pic from their online manual to illustrate what I am asking.
Can any of the bits indicated in green be easily removed (without special tools and risk of damage !) to allow access to the prime focus and get it onto a Canon sensor (using a T adapter or something similar) ?
Thanks for any help/suggestions,,
.
350.jpg

Thl05
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Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

76 views (as I type) and no one has one (or not admitting to it !) which tells me I should not even contemplate getting one !!!

Or maybe I should, to find out what is so wrong with it(them) !

Ichthyophthirius
Posts: 1091
Joined: Thu Mar 07, 2013 5:24 am

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Ichthyophthirius »

Hi,

We would certainly try to help you if we knew the answer :cry:

I suspect that very few people here have this microscope. Although photography will certainly be possible with such a microscope, most users will quickly move on to a more mechanically (and optically) sound second hand microscope from one of the established manufacturers.

There are good reasons for buying a solid mid-sized microscope stand from one of the major manufacturers (Zeiss, Leitz, Olympus, Nikon, but also Zeiss Jena, Reichert, PZO, Meopta, Lomo and so on) - they all have "issues" when it comes to second hand microscopes but their universal stands can be adapted to different contrast techniques and there are usually plenty of people around that can advice on technical details and repair!

That said, there are few 160 mm tube length microscopes around that would allow you to do direct projection (sensor at the intermediate image plane) and visual observation through a trinocular tube. Because they were designed for film (35 mm at the least), they usually employ eyepieces (afocal) or projectives to magnify the intermediate image for photography.

There are a few "hacks" that would allow you to do direct projection on a traditional stand, requiring at least the use of some custom-made adapters. In other cases it is impossible. A short flange focal distance helps. When you say "Canon" you mean a Canon APS-C DSLR (flange focal distance 44.0 mm)?

What's wrong with the Meopta stand?

Regards,

Ichty

Thl05
Posts: 14
Joined: Wed Nov 27, 2019 6:10 pm
Location: SW England

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Ichthyophthirius wrote:
Tue Jul 14, 2020 2:42 am
We would certainly try to help you if we knew the answer :cry:
I suspect that very few people here have this microscope.

eyepieces (afocal) or projectives to magnify the intermediate image for photography.

the use of some custom-made adapters.

What's wrong with the Meopta stand?
Hi, Thanks for your interesting reply, lots to think upon.

Yes, I was beginning to suspect the same ! :)

Canon 60D (in the first post), I think that is an aps-c ?

The Meopta stand is ok, nice and solid, my prob is just the precarious arrangement I currently have of extensions and helicoid, simply resting on top of the Meopta stand after the eyepiece tube and prism? is removed. One accidental hit on the table, or inadvertent tug on the remote trigger, and it is all liable to fall down in a heap ! It will need some expertise in a workshop to make an adapter to mate with the lugs etc in the head.
I was hoping someone could show/describe the Swift to see if that might be easier to make a simple tube to slot in.
Else some sort of stand alongside (like a re-purposed drill press or an old film enlarger, still in my attic :) ! )

Here my photos of the current arrangement. And the very short 'land' with protruding lugs that prevents simple hand tool construction of an adapter.
MeoMod.jpg
631.jpg
608.jpg

Ichthyophthirius
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Joined: Thu Mar 07, 2013 5:24 am

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Ichthyophthirius »

Hi,

You need a dovetail adapter to connect the microscope stand with the helicoid!

You could have this custom-made, 3D printed or you could try to scavenge it from other equipment.

The Meopta monotube looks similar to the Lomo version. In the Lomo version, you can unscrew the dovetail (blank metal) from the tube (painted black). Extreme caution is needed as there is a glass prism or mirror in the base that gets easily scratched. Is it possible for you to unscrew the dovetail? If so, you might have a thread for a connection to the helicoid.

-----

The low magnification achromatic objectives on your microscope might work without compensating eyepieces, but the 40 and 100 won't. They require compensating eyepieces. So a direct projection approach will only work well at low magnification. For high magnification you would need a full microscope setup (probably afocal) for best results. Just keep this in mind before you sink a lot of money into the direct projection approach.

Regards, Ichty

Thl05
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Joined: Wed Nov 27, 2019 6:10 pm
Location: SW England

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Thanks for your continuing interesting thoughts.

Part1 (part2 to follow later)
Ah! I think you must be telepathic :) I was going to post further down the line about the results that I wasnt getting with the 40x ! Yes, very mushy in the middle and out of focus everywhere else !!! I suspected this was down to the unsuitability for direct projection.

It is a longish story and I didnt want to overload a first post :)

When I first acquired it all 4 (4x 10x 40x &100x) of the meopta objectives gave very poor results (with its one eyepiece) to my aged eyes. I blamed my eyes! Later I found that I had also inherited another 10x still in its storage housing and looked in a better state of preservation than the meopta bits. This one produced usable results even with my poor eyes and bad back ! Hence trying out projection to the dslr, with the intention of sitting comfortably at a large screen.

So, back to topic ;) the trino tube in the Swift pics looks like it should disassemble into shorter segments and might be more convenient than my meopta contraption. So far it has all been zero cost, and yes, I need to not spend too much until I learn a bit more.
I would not expect great things of the Swift and it is in the 'pocket money' range to at least give me a starting baseline and something to play with.
On the other hand I may just go with the Swift as-is and the convenience of a 3Mpixel usb eyepiece cam. (for which use one of their monos would do as I will not be using it very much with my Mk1 eyeballs!)

Anyway that is a bit more background about why I wanted to ask the (quicky !?) question about the trino construction, you see :) :)

More later about how I could not find a way into the eyepiece/dovetail assembly, no slots, screws, keyways for C spanners, nothing !
And perhaps later some pics of results so far, including attempts with a 6.3x plan (also in the box of bits) which turned out to have a funny ring inside it ! Yep, that introduced me to the concept of phase rings, all I have to do now (I mean laters !) is find the condenser and/or the scope it came off.

Dont tempt me with 3D printing, I have long wanted an excuse to investigate them lol!

Thl05
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Joined: Wed Nov 27, 2019 6:10 pm
Location: SW England

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Ichthyophthirius wrote:
Tue Jul 14, 2020 8:51 am
The low magnification achromatic objectives on your microscope might work without compensating eyepieces, but the 40 and 100 won't.
Part2 after evening meal :)
Do you mean those specific objectives in my picture ? Or 40x and 100x in general ??

If the latter how do the low end Swifts and the like do with their eyepiece cams then ? Unless I am mistaken, they are receiving direct projection. Only the high-end HD cams appear to have lenses with them.
I dont expect to need 100x, but 40x would be nice to use, (and later perhaps 60x from China via ebay) I dont see on the web horrid reports of them being unusable. Nor any reports extolling their virtues for that matter !
A certain "hunter of microbes" elsewhere doesnt scold them either when talking eyepiece cams, sooooo I am a bit puzzled ! I didnt notice which of the objectives were on in that pic, I think only two were the meopta originals.

Ichthyophthirius
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Joined: Thu Mar 07, 2013 5:24 am

Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Ichthyophthirius »

Hi,

In the Lomo monotube, the bottom metal part can be screwed off just like a jam jar is opened. Obviously don't try too hard and break it!

Alternatively, you could take precise measurements (not just bottom max. diameter! for you the diameter at or near the top is crucial) and see if a suitable dovetail-M42 Adapter is available from RafCamera https://rafcamera.com/catalogsearch/res ... microscope

[By convention, you would write the magnifications of finite tube length objectives (160 or 170 mm tube length) as "40:1" or just "40" (is number is the magnification at the correct tube length); objectives for infinite tube length would be "40x" (magnification is only correct with the matching tube lens).]

Most objectives 40:1 and 100:1 (high magnification finite objectives) did require compensating eyepieces. The only exceptions, starting in the late 1970s, where Nikon CF objectives and a few Zeiss Jena objectives. I actually found one reference claiming that Meopta also had some 170 mm objectives not requiring compensation (but this is nowhere in the literature I know).

Most modern infinite biological microscopes (Zeiss Jena starting in the 1980s, the others major companies from the 1990s) don't require compensating eyepieces. But a few of the cheaper ones still do!

In cheap microscopes, you might have compensation by the tube lens, by the eyepieces or the C-mount adapter lens (if there is one). Or no compensation at all, which you won't see if you use a low MP camera. I don't know any systematic tests and there can be positive surprises, especially at low magnifications. If you can't find another owner of this microscope, it will be trial and error. You will probably miss the solid mechanical quality of the Meopta!

Without a compensating eyepiece, your 40:1 should still give a sharp image! Sharp, but with sharp colour fringes. If the image is misty, there might be other problems. Often there is immersion oil on the front lens. Or the objective was used without cover glass or with a thick layer of water.

Regards, Ichty

Thl05
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Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Ichthyophthirius wrote:
Tue Jul 14, 2020 2:44 pm
Without a compensating eyepiece, your 40:1 should still give a sharp image! Sharp, but with sharp colour fringes. If the image is misty, there might be other problems.
Fascinating stuff, much to learn and much to come back to later (especially the dovetail/raf bit)
and "the other problems" are most likely me not knowing what I am doing !and not having proper illumination, it is missing.

But for now I have to tell that I blundered ! The objectives are 6, 10, 45 and 100.

They dont have 160 or infinity markings nor coverglass thickness, just two numbers in pairs on each 6 0,15 10 0,30 45 0,65 and Ol.im. 100 1,25 and then the Meopta logo with what look like a serial number under it on the other sides of them.
I chose the ext. tubes to approximate the 160/- of some of the other objectives that I have, but perhaps this does not suit the meoptas ?
s1220747.jpg
ss1220574.jpg
Last edited by Thl05 on Wed Jul 15, 2020 10:33 am, edited 1 time in total.

Ichthyophthirius
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Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Ichthyophthirius »

According to my literature, Meopta had 170 mm tube length and 11 eyepiece parfocal length. So the tube length for direct projection should be 159 mm. At that distance, all the Meopta objectives will be parfocal at you sensor. The Zeiss 6.3 won't be exactly parfocal at the same length.

Small diviations from the correct tube length don't affect image quality for the 6:1 and 10:1 (they only affect parfocality), for the 40:1 and 100:1, the tube length should be correct within a few mm for best results.

I have no data on whether the objectives require compensating eyepieces; if no-one else chimes in, you have to judge at yourself. It's a real shame you don't have the propper illumination. It makes a big difference at high magnification.

Thl05
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Re: (Updated)Objective projection SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Once again you have given me lots to think upon and things to try, thank you very much.
It is reassuring know that I was not a million miles out with my projection distance, I was begining to think that it might have been one of the causes of my difficulties and that I may have needed to go back and vary my tubes for the Meoptas !

"Small diviations ,,,, 6:1 and 10:1 (they only affect parfocality)"
Good thanks, so when I have sorted out the meopta lenses (may need cleaning by an expert !) that makes me think that adjusting the helicoid to bring both to parfocal would be a good way of checking their tube length ? An experiment for the future.

"compensating eyepieces; if no-one else chimes in, you have to judge at yourself. "
Indeed, I will be pleased just to get some half-reasonable viewing in !! and sort out the finer points later.
To which end I must find my comparison pics of the two 10 objectives and let you all see and comment upon them, or to even make some more carefully documented new pics for you all (now that I know a bit more about what to expect !)

Meanwhile I have more illumination experiments* to do with an assortment of LEDs, one of them (a flat panel array) can be seen in the previous pics doing top (epi?) illumination.
Not quite so successful yet as transmission. I thought, when reading about Kohler, that the idea was to make for an evenly illuminated field just below the condenser from a fillament some distance away. So, an evenly illuminated flat panel should bypass all the Kohler gubbins ?? hmmm not quite happening for me yet :( That is a whole other topic ! :)

*edit : It came with a tiltable flat+convex mirror an a stalk that was a loose and wobbly fit in the hole where the real lamp housing / illumination should be plugged in.

Thl05
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Re: Objective projection, SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Ichthyophthirius wrote:
Wed Jul 15, 2020 3:16 am
if no-one else chimes in,
I have put the promised comparison pics in a new topic so that others can see that we have moved on a bit from Swifts :) !

Still no joy at undoing the dovetail, just no way to get a good grip on it, and I dont (yet) want to risk doing damage that could not be undone by someone more experienced. Shame, because the RAF site looks full of good gizmos.

Ichthyophthirius
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Re: Objective projection, SwiftSW350T on to camera (Canon) sensor

Post by Ichthyophthirius »

In that case, can you measure the dovetail dimensions (hight, min and max diameter; angle to confirm)? It looks like the Lomo/Jena dovetail but it could be anything.

Thl05
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Re: Objective projection, SwiftSW350T on to camera (Canon) sensor

Post by Thl05 »

Using this Meopta has become less desirable since I have noticed another problem (foible, feature), the turret/head etc plus anything weighty (like the dslr+bits) is carried upon the focusing mechanism which makes the focus mechanism stiff. Even worse, any slight pressure or disturbance to the dslr, or turret, makes a slight change of focus :(

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