Amscope, should I return it?

[rasiel]

Hi group. I'm new to the list and to the hobby having come from a background familiar with macro. I set out shopping for a microscope with which to study coins at a higher magnification than normal macro allows. After doing the best I could just reading reviews on amazon and ebay (oh why oh why didn't I come here first?!) I ended up buying a zoom amscope trinoc and a t-adapter for my Nikon. This is the basic setup:



I thought this was all I needed to get started but evidently either my expectations are too high or my gear is crap or I'm doing something wrong (probably all three). Maybe someone with more knowledge can guide me. At this point I'm thinking of returning the unit but if I could improve my technique and/or the equipment itself I'd rather go that route.

This image is of a coin surface. Notice the 'orrible orrible CA and off-center blurring that I think would be unacceptable for even a pinhole camera.



Since the view at the eyepieces doesn't seem *quite* this bad I'm wondering if the culprit is the $100 no-name adapter optics:



While the adapter fits into the tube casing very, very snugly the whole head and body have a lot of roll and wobble which can't be good for dampening vibrations. The coin shots were stabilized only thanks to the timer and temporary mirror lockup.

Other notes of interest are that the image on the camera appears upside down and isn't parfocal. Adjusting focus via live view or viewfinder is very difficult due to low light. I am, on the other hand, asking max power out of this thing which is a 4.5x objective + 2x barlow + whatever the adapter optics add to this - just too much?

So, here's some questions... please, I would appreciate any answers to any of these:

- Am I just asking too much from sub-grade equipment?
- Am I doing something wrong?
- Can I improve this setup?
- Should I return the whole kit and kaboodle and start over with something better? If so, what do you recommend?

My primary aim is to photograph coins at high magnification though, hey, if I could take pics of microbes too that'd be a nice bonus. I don't have a budget really but would prefer to keep it under a grand at least to start. I know well the "creep" that drains the bank in the chase for higher quality but really do need reasonably decent quality for Day One.

Anyway, for what it's worth, you might also be interested in a blog post I wrote with the results though here the images were liberally photoshopped!

http://www.dirtyoldcoins.com/Roman-Coin ... nstantius/

I want to say thanks to the whole group. I spent several hours today reading old posts and I'd love to contribute in the days to come :-)

Ras

[rjlittlefield]

Ras, welcome aboard!

I agree, the image looks awful. Worse, I am not optimistic about getting it to look good with this scope, and I'm also not sure that shooting through any stereo scope is the best way to accomplish your goals.

I should temper that bleak assessment by saying that I have no experience with that particular scope, and I'm not aware of any postings that talk about it. I'm speaking only from a position of general experience.

However, reading your post I'm struck that you don't seem very pleased by what you see through the eyepieces. Sometimes people post that the view through the eyepieces looks great but the camera images don't. In those cases we can sometimes narrow down the problem and suggest adjusting or swapping out the adapter. But it's very rare for the camera to give a better image than the eyepieces, so if even the eyepieces don't look good, I'm thinking you're at a dead end.

Now, backing up a bit...

Stereo scopes are great for direct observation because they show depth, they're very convenient, and you can easily manipulate the subject to look at the particular detail you're interested in. I use mine daily for looking at stuff, and if it dies it will be replaced immediately.

But for photography, stereo scopes leave a lot to be desired. At best, they offer only about the same resolution as a good macro lens. That's because the aperture on the stereo scope is kept small in order to deliver good depth of field. There's no getting around diffraction blurring caused by a small aperture. Inexpensive stereo scopes are also inclined to get soft away from image center. That's OK for direct viewing because users will happily reposition the subject to center whatever they're interested in at each moment. But for photography, it's a huge problem.

If you want to focus on getting high quality photographs, I suggest using bellows and a reversed enlarging lens like the commonly available EL Nikkor 50 mm f/2.8. With your camera (Nikon D700, 12 megapixels and full-frame sensor, 36 x 23.9 mm), the EL Nikkor will give tack-sharp images up to around 5X on sensor, giving you a field of view similar to what you'd get at around 30X through the microscope. You can push the EL Nikkor to around 10X and it'll still look pretty good. Beyond that, you'd replace the EL Nikkor with a microscope objective, probably 10X NA 0.25, using one of the schemes described in our FAQ: How can I hook a microscope objective to my camera?.

You mention that you're familiar with macro, but I don't know exactly what that means. You may already have much of what you need. What's in your kit?

--Rik

[rasiel]

Rik - big thanks for your helpful reply. I had no idea that stereo scopes were a compromise from the get go for one.

My studio setup for macro is pretty simple, consisting of the D700 body, Nikkor 60mm and some custom lightwork and props. I've never used bellows or extension tubes. Is the t-mount w/ special lens an inferior route? I'm guessing it is but would like to know for sure what the disadvantages are (optics? convenience? vibration?). My preference would be to not leave the sensor exposed to dust while inside the bellows but I'm not hardset about it.

Please give me some general idea of a better suited tool for the job so I can start shopping for a replacement. Again, the main task at hand is to photograph coins at as high magnification as possible. I've seen several metallurgical scopes advertised of inverted design but I think this would be too awkward.

Will welcome any advice. Likewise if I can help answer any questions regarding this scope for the benefit of the group ask away!

Ras

[specious_reasons]

I actually use the AM Scope adapter. It's ... sufficient. The quality is comparable to the images I see from the microscope.

This is my photostream, in case you're curious.
http://www.flickr.com/photos/28594931@N03/

It's also not parfocal for me, it's slightly off.

One thing I can think of - the assembly can be screwed apart, and it's possible that it's not fully tightened. That might help with the wobble.

[rjlittlefield]

I actually use the AM Scope adapter.

specious_reasons, can you clarify what scope you're using that adapter with? Looking at your photostream, I'm guessing it's on a condenser-equipped compound scope, not a stereo.

Is the t-mount w/ special lens an inferior route?

I assume you're referring to the adapter setup, working through a scope as shown in your post.

The main positives of the adapter approach are convenience and cost, especially if you want to have the scope anyway for other purposes. In that case, if you can get the system working properly then it becomes "what you see is what you get". In addition, the scope provides a mount for the camera and a focus mechanism that you can use for focus stacking, which you'll be needing at higher magnifications.

The main negative of the adapter approach is lower image quality than you can get with good macro lenses & microscope objectives used as described in the FAQ that I linked. If you think of the optical system as a chain, then clearly it's only going to be as good as its weakest link. Really that's optimistic, since problems in all the stages tend to add together in the final result. So if there are limitations in either the main objective of the stereo scope, or whatever routes the image to the trinoc tube, or the camera adapter, you see them in the final result.

If you did want to put together a bellows system for use at high magnification, you would need the following components:

• bellows
• reversing ring, e.g. Nikon-to-52mm male
• adapter rings to fit lenses
• lens
• focusing rail

Bellows come in a wide range of capabilities and prices. I'd probably start with a bare-bones unit where only the front standard moves. Those are available new on eBay and at Amazon for about $35. Likewise for the reversing ring, about $8. An EL Nikkor 50 mm f/2.8 would come used from eBay, ballpark $70, plus a step ring to fit the reversing ring, $5. To do focus stacking, it's best to have some kind of micrometer stage or screw table. The Proxxon KT-70 generally gets good reviews, around $100 at Amazon. Stacking software, Zerene Stacker at $89, or if you're willing to fiddle, CombineZP for free. Going up to a 10X microscope objective, you'd be looking at another $120 in new parts for say a Nikon Finite Conjugate 10X from Edmund plus the adapters to mount it on the bellows.

Adding this up, I get around $350-450 for the whole mess. Obviously this is not a cheap way to go if you're going to keep the scope also. But it's a well trodden path that's known to give good results.

I have no idea what your budget is like so I'll mention also that there's a device called StackShot that provides a motor-driven rail with resolution down to 1 micron. It's a wonderful device for automated stacking and has plenty of precision for any objective you'll be using. I use it regularly at 40X and 50X on sensor -- equivalent to 500X through a microscope. See HERE for a portable system built around it.

Leaving the sensor cavity exposed inside a bellows is something that everybody worries about but doesn't seem to be a big problem in practice. I've heard of sealing off the back of the bellows by taking apart a clear filter and gluing its glass into the rear mount of the bellows. That sounds straightforward and optically it's fine, but it's a rare procedure.

I hope this helps. Tradeoffs, tradeoffs...

--Rik

[specious_reasons]

I actually use the AM Scope adapter.

specious_reasons, can you clarify what scope you're using that adapter with? Looking at your photostream, I'm guessing it's on a condenser-equipped compound scope, not a stereo.

Correct. I'm using the same adapter, but I'm using it with a compound microscope. I have a Labomed Cxl with a variety of objectives.

Obviously not the same setup, and I'd imagine that the build quality can vary greatly among these adapters, but the one I have is adequate for the job I've tasked it.

I haven't experienced that the adapter is loose or wobbly, but I do know that it can be disassembled to a certain extent, and that it might not be assembled tightly. The eyepiece and camera T-ring adapter screw into the larger body, and one might be loose. It should be a very easy thing to check, even though it doesn't solve the larger problem.

[pjoris]

I have a similar adapter and while it works fine on a compound, it is more poor on a steromicroscope (both reasonably high end olympus models from the 80s). In fact on the stereozoom, photographing through the regular eyepieces with a camera with lens ("afocal approach") works better.

However, I don't think you can expect very good results photographing at the high end of the zoom range of most stereozoom microscopes. Adding a 2x barlow lens will not improve either. At the lower end of the zoom range it should work better, but that may not give you sufficient magnification ?

Joris

[Olympusman]

I have been dealing with frustration on my trinocular stereo scope as well. I have an adapter on the camera tube with a Four Thirds mount and have tried to get decent image quality with an Olympus E-420 and an Olympus E-P1, with little success. Like you, my setup is far from parfocal and I'm using a 10x relay eyepiece in a modified Pentax microscope adapter.
Just this last weekend I gave the camera tube another shot, and didn't even get an adequate image. I've been fighting this battle for over a year, and I think I'm going to put a wireless TV camera back on the camera tube, which had worked very well.
However, I have gotten very good results shooting through one of the eyepieces with an Olympus SP-320 using a mount I built myself.
This last weekend I took a few vacation days to clear up a number of loose ends in my microscope lab. I resurrected my phase contrast scope and mounted an Olympus Stylus 810 compact camera to one of the eyepieces using a digiscoping adapter and got very good results. So I ordered a couple more of the same model digiscoping adapter to replace my homemade mount on the stereo scope, and I should get very good results with the SP-320 shooting through an eyepiece.
It means giving up streo viewing, but it means I will be able to get quality images on subjects too big for a compund scope.
I have found compact cameras work very well on eyepieces as long as the front element of the camera lens is the same size or smaller than the exit pupil on the eyepiece.