B&L Stereozoom Photography ?

[MichaelG.]

This patent is too clever for me to fully comprehend, but I think it may be relevant to the SZ7
https://worldwide.espacenet.com/patent/ ... DGB988120A

Note the paragraph commencing page_2 line_114

MichaelG.

[einman]

Guys,
Not to interject into your in depth conversation but, if you are serious about using the SZ7 for photography, and even perhaps image stacking, I would suggest you obtain the research stand as pictured below. The focus mechanism is designed a "fine" focus and trust me compared to the other stands available for the SZ7 is is very fine. It is built incredibly well and can be obtained with various options. The one pictured has the slide stage. It also has the substage illumination, although not on it in the photo. The most difficult part with using the substage illumination is finding a power cord. They are hard to come by and are not an easy to find plug type.

[BramHuntingNematodes]

Yeah always keeping an eye for a reasonably priced r stand not even a quarter as common as an sz7 in working condition though

[Sliding Focus]

How do you feel about disassembling, at least partially, for more careful inspection/cleaning? I am not sure what is involved (have an SZ7 but have not taken it apart yet) but it may be difficult to troubleshoot further without having a look inside. Seems like there are quite a few people on here familiar with the internals that could help and I have seen manuals and exploded-view parts diagrams posted before.

I’d consider opening up the camera adapter if I were confident that I could put it back together afterward, but I don’t want to disassemble the power pod. Since I’m lucky enough to have the microscope, I’ve been using it to work from home through the pandemic, and I lent my work microscope to a colleague so that they can do the same—so taking it out of commission right now would be a problem for me. Plus, I don’t have the tools for that kind of precise work (though I could acquire some if I wanted to). But I do appreciate the idea—it could be helpful for diagnosing my issue—and I would certainly be grateful for guidance here were I willing to do that.

[Sliding Focus]

Not to interject into your in depth conversation but, if you are serious about using the SZ7 for photography and even perhaps image stacking I would suggest you obtain the research stand...

Yeah always keeping an eye for a reasonably priced r stand not even a quarter as common as an sz7 in working condition though

Seems like a helpful interjection to me! What would you all consider a fair price for one, if you don’t mind my asking? I’ve had a saved search for the R stand on eBay for a while, but haven't seen one turn up for anywhere near a price that I'd be willing to pay.

[BramHuntingNematodes]

Not a thick enough market for anything like a "fair" price. I would pay maybe $60 for a broken one. More than $150 and more creative solutions start to become.possible. I don't think they are collectors it's as much as just a nice bit of gear to go with your good and cheap sz7

[hans]

How do you feel about disassembling, at least partially, for more careful inspection/cleaning? I am not sure what is involved (have an SZ7 but have not taken it apart yet) but it may be difficult to troubleshoot further without having a look inside. Seems like there are quite a few people on here familiar with the internals that could help and I have seen manuals and exploded-view parts diagrams posted before.

I’d consider opening up the camera adapter if I were confident that I could put it back together afterward, but I don’t want to disassemble the power pod. Since I’m lucky enough to have the microscope, I’ve been using it to work from home through the pandemic, and I lent my work microscope to a colleague so that they can do the same—so taking it out of commission right now would be a problem for me. Plus, I don’t have the tools for that kind of precise work (though I could acquire some if I wanted to). But I do appreciate the idea—it could be helpful for diagnosing my issue—and I would certainly be grateful for guidance here were I willing to do that.

Understandable. I hope to get around to messing more with the ones I have soon, maybe over the holidays, will keep an eye out for similar symptoms.

This patent is too clever for me to fully comprehend, but I think it may be relevant to the SZ7
https://worldwide.espacenet.com/patent/ ... DGB988120A

Drawing is pretty different compared to this one viewtopic.php?f=5&t=10403#p89264 covering a coaxial illuminator. I don't remember if I saw any microscope patents showing the same optics as that coaxial illuminator one, and not enough firsthand experience (yet) to say how well any of them actually match SZ7.

[MichaelG.]

Drawing is pretty different compared to this one […]

.

True

MichaelG.

[BramHuntingNematodes]

Dang I finally found a good camera adapter and took it apart and bought a new mirror for it from EO and set that up and lubed it and adjusted it and I got the same exact issue as sliding focus. I've already taken apart that sz7 head so many times and gotten it working perfectly sharp focus and parfocal zoom. The look through the eyepieces is perfect whether using the 31-15-71s or the -74s. There are two grub screws that fix the angle of the second mirror in the camera adapter and I will try adjusting those to get the image better focused on the center of the eyepiece FOV is the last thing I can think of.

[Sliding Focus]

Dang I finally found a good camera adapter and took it apart and bought a new mirror for it from EO and set that up and lubed it and adjusted it and I got the same exact issue as sliding focus.

That is unfortunate! I still haven't found a solution, but have been procrastinating on following up with a repair person who may or may not be able to help me... I will send an update if anything ever comes of that.

If you have (or are willing to make) any, would you be willing to share photos of the inside of the camera adapter and more info. about the adjustments you've made/are making?

[BramHuntingNematodes]

I will! Thanks sf.

[BramHuntingNematodes]

So here I am holding the thing upside-down:


Enhancing the image, we can see the backside of the second mirror and the three hex screws that use the notorious B&L .05 inch Allen wrench.


One of the three screws is obscured by the spring, but it's there and can only be accessed by ripping the B&L sticker off ala:



It's that hole there. So I have gotten the image centered exactly in line with the eyepiece, but the blur remains, almost as if the second mirror wasn't first surface or something.

[BramHuntingNematodes]

Hmm I think your supposition about astigmatism may warrant further investigation. There is an optic inside of the adapter to help make the adapter parfocal. This can also be adjusted by means of a screw. However, if a bad placement of the first mirror is compensated by changing the angle of the second mirror, we may have our subject passing through this internal optic off axis. You can also slightly adjust the position of the mirror from the outside as well with I believe 1/16th allen wrenches and a screw on the back and one on the side. It may take repeated iterations of adjusting these, then adjusting the second mirror to get the best result. If someone has a manual for the camera adapter, it may have a process for establishing this match.

[BramHuntingNematodes]

Oof so I have obtained some improvement here goes:

The first mirror I made perfectly level. If you notice, the lens inside has an angle corresponding with the left angled optical path. This angle finds its exact complement with the second mirror. There are two screws with spring washers on the inside holding the mirror assembly in place. These can be loosened if the assembly is not properly seated. If you don't tighten them all the way, you can still adjust its position slightly using the two grub screws accessible from the outside of the case on the back and side. My side screw hole had a bunch of rubbery goo in it, I guess to keep out light.

Separately, there is a grooved track held in place by two screws. This grooved track has an important relationship to the cylinder which holds the optic in that either can keep the first mirror from fully extending when the lever is turned by catching. A little light oil is in order, and you can also make sure the grooved track isn't positioned so that it squeezes against the sliding assembly too hard. In addition, my example had a little dimple on the collar around the optic cylinder from where the catch wound up on the wrong side and someone previously tried to force the mechanism back into place (it's my suspicion that this unit never worked properly as the mirror that came with it was slightly too large to fit in any orientation, moreover, every screw internal and external had signs of wear).

Anyway, I filed this dimple flat as it also caused the optic cylinder to catch. There is also screw that fixes the optic-- better make sure this is not tightened completely or the parfocal adjustment will not function. Too loose and the optic can twist out of place. The first mirror assembly should slide completely forward every time the lever is pulled. After this is taken care of, it's mostly a matter firstly fine tuning the parfocality using the flat-head screw on the back of the unit. It's the one on the bottom right when looking directly at the back. You have to keep up with the catch as you adjust it as turning the adjustment screw counter-clockwise will cause it slip and end up ono the wrong side of the optic cylinder flange if the bottom is taken off, and it will be at this point. Once it is exactly parfocal with the eyepiece, make small adjustments to the three grub screws at the second mirror, keeping track of how they adjust the image. Again, ideally the second mirror will be at the complementary angle to the lens, but you'll probably need to do a bit of fine tuning to center the image. You will also then have to adjust the parfocality again, then the position again and so on until both are about right. The image should now be parfocal with the eyepiece, centered to the eyepiece and parfocal throughout the zoom range.

Anyhow, this is what I did on my scope's adapter and it looks a bit better but was also an enormous pain in the ass.

[BramHuntingNematodes]

The patent is pretty close to the actual product:
https://patents.google.com/patent/US349 ... 101&page=1

[BramHuntingNematodes]

In the second photo on the right you can also see a set screw. This screw allows the optic #62 to move forward or back about 15mm or so. I am also now trying to figure out how to position this lens in relation to the front lens, comprising yet another wrinkle. I am reasonably certain I know have a complete adapter in good condition, but the adjustment process is maddening.

[BramHuntingNematodes]

OK well basically nearing the end of my rope here. If anyone has a clue, here are the comparisons from the left eyetube and the adapter using the same camera setup and adjusting the adapter to be parfocal.

First here is through the eyetube, a reasonable approximation of the crisp images I am used to looking through my SZ7:



And here is this garbage look through the adapter:




It's less noticeable in close-up, but you can still clearly see the color fringes through the adapter view. If anyone has any idea, it would be enormously appreciated.

[Sliding Focus]

Bram, thanks for sharing all this info! (And sorry I haven’t been contributing to the thread lately.)

I’m pretty sure I have instructions for the camera adapter somewhere. Not sure if they’ll be helpful—they don’t have any info about the internal adjustments you’ve described here—but maybe they might offer some insight? I’ll try to find and share them sometime this week.

[Scarodactyl]

Interesting that the CA is not radial, and is all oriented in the same direction. Wish I had an answer, I never did any intensove testing of my setup when I had it. My dad still has the one I set up for him I guess.

[BramHuntingNematodes]

Bram, thanks for sharing all this info! (And sorry I haven’t been contributing to the thread lately.)

I’m pretty sure I have instructions for the camera adapter somewhere. Not sure if they’ll be helpful—they don’t have any info about the internal adjustments you’ve described here—but maybe they might offer some insight? I’ll try to find and share them sometime this week.

Thanks! Every little bit might help.

[hans]

Bram, were those all taken with the same exposure settings? Oddly the full image through the camera port looks noisier to me but I don't notice much noise difference in the 100% crops.

[BramHuntingNematodes]

Probably not. Visually the adapter view is dimmer.

[hans]

If the adapter is somehow blocking off a significant portion of the aperture (leaving only an offset sliver near the periphery) maybe that could explain both the dimmer view and the lack of radial symmetry in the CA that Scarodactyl mentioned?

[BramHuntingNematodes]

That seems likely. The two aspects that have to align are making sure the first mirror is over the optical path and making sure the second mirror is directing the rays correctly. I can't seem to get them both at once.

[Sliding Focus]

Hi all! Sorry that it's taken me so long to get back with this, but here is the manual for the camera adapter:

















In case you want higher-res versions of the images, you can find them in this Flickr album.

I hope this helps!

[BramHuntingNematodes]

Thanks! I will give it some study.