Hooking up a microscope objective to my DSLR camera?

[chrisiieeg]

Hi Everyone.

I am new to this forum and macro (while i have been reading the last 6 months, this is my 1st post). Like to start with saying that this forum has been a great source of learning for me and am grateful for everyone’s input to such a great site. I tend to get long winded (which I believe my post will be), so I will attempt to keep it simple (written in point form is possible)

My interest in macro started since mid last year, where insects are my main subjects, taken with the simple setup as below.

Main Setup (A)

• - Canon 550D +
  - Tamron 18-270mm (reversed) +
  - Focusing rail (http://www.aliexpress.com/snapshot/203439436.html) +
  - Cable release +
  - Tripod +
  - Ring flash

Max magnification I am able to get with this setup, is a 5mm object fitting to almost ¾+ of my sensor. (Q. Maybe someone can help me work out, even if it is a rough estimate, a numerical magnification?? 5x ,10x? I wouldn’t have a clue).

Here are some of the better results (at maximum magnification) I have been getting with this setup.


Stack of 27, its head approx 5mm wide, no adjustments except for levels, full sensor image resized to 1024px wide.


same picture as above, at 100% size and cropped to 1024px wide.


Stack of 30, spider about 5mm wide, no adjustments except for levels, full sensor image resized to 1024px wide.


same picture as above, at 100% size and cropped to 1024px wide.

Rare setup (B)
**on rarer occasions (instead of the Tamron), I would try to use my kit lenses, 18-55mm reversed (set at 18mm), screwed on the end of 55-250mm (set at 250mm). While I get highest magnification possible with what I have, it is also very difficult to do macro with it, due to vibration/weight of lenses and lack of finer focusing rail dials etc. Magnification wise, I manage get a 2-3mm object to fit to my whole sensor (Q. what that in numerical mag ?)

Here are some of the better results (at maximum magnification) I have been getting with this setup.


Stack of 8, its head approx 5mm wide (same fly, but 2 weeks later, decomposing ), no adjustments except for levels, full sensor image resized to 1024px wide.


same picture as above, resized to 50% and then cropped to 1024px wide.

It has been my interest and/or goal, principle, challenge to

• - acquire knowledge to improve the techniques and gain understanding of all that is involved with macro photography (still a long way to go – I lack the technical from optics/physics/maths understanding of it etc etc).
  - appreciate all of GODs creation .
  - see how good a picture I am able to take with as little expense (I don’t have much $$$ to part with…who doesn’t ).
  - see if my new found interest in macro/micro, would stand the test of time. Eg. no point spending big $$$ on MPE-65 if the novelty would just wear off quickly. I could do “just as good” more cheaply (well, maybe not as good, but closer). No doubt in time, my ongoing interest would dictate how much more I will invest in equipment

With the above in mind (goals/interest etc), and what I have learned so far with techniques and workflows etc, I would like to expand into area of micro (DSLR+objective lens. **10x magnification to start with). I have some questions here before I proceed with any purchases

Reading (http://www.photomacrography.net/forum/v ... hp?t=12147), Rik mentions two fundamentally different approaches for “DSLR+Objective lens” setups (finite vs infinite objectives).

Reading (http://www.microscopyu.com/articles/optics/cfintro.html), confirms (I think) my superficial understanding of why I “must”(?) use finites with extensions, and infinites with tube lens (due to light pathways etc).

• • Q1. Does that explicitly mean if I tried use a 160 finite objective + tube lens (Tamron) set to 150mm, I will not get any usable image (if any) ?
  • - If I can, then how decent an image do I get? pros/cons?
    - even non-branded objectives finite/infinite are approx $40/$100. Big diff in price.
    - It is my intention to be frugal with the setup until such time my growth in interest warrants spending more.

• • Q2. Regardless of finite/infinite setup I go with, would I have greater difficulty with stacks than with my setup (B) due to its high magnification?
  • - With the cheap focus rail I am using, I am barely even turning it, (more like nudging), hoping each time I do, that it is moving the right amount forwards (which from my samples, are clearly not the case !! J)
    - Hence, with 10x objectives, is it advisable to not even try without considering a better focus rail equipment?
    - If DSLR+Objective is more forgiving, then my setup (B), then my next question is “what to buy”! .

I plan to purchase the following

• • objectives (which I hope is RMS thread)
  • o 10x Finite – No Brand/Cncscope (http://www.ebay.com/itm/New-10X-Plan-Ac ... 4aa54df60f)
  • This is and “oil spring” lens. Is it referring to the fact that it is “oil immerse” & “spring loaded” ?
  • o 10x Infinite – No Brand/Cncscope (http://www.ebay.com/itm/NEW-10X-INFINIT ... 4aa50e3809)
    
    o Q3. Are the above objectives even close to what I need ?
    • • Given my subjects (insects) are opaque, and episcopically illuminated
      • Does that mean I need a metallurgical objective ? if I do, would the above suffice?
  • RMS to M52 - female RMS to male 52mm (http://www.ebay.com/itm/RMS-8-microscop ... 0750438193)
  
  • 72mm to 52mm step down ring (http://www.ebay.com.au/itm/72mm-52mm-Ca ... 0828883161)

Thanks all in advance for any input any of you may have.

Regards

Chris.

[Chris S.]

Welcome to the forum, Chris! (You’ve probably noticed that several of us here share your name—sometimes it sounds a bit echo-y.)

You’ll probably get more feedback if admin moves your post to the “Beginners Macro” section, rather than the FAQ section where it is right now. In the meantime, I’ll take on one of your quicker-to-answer questions.

You can determine the magnification of an optical rig by photographing something of known size, like a fine ruler, which lets you measure the field of view. You’ve done something like this, a bit more roughly, by estimating the size of a frame-filling object. To be clear, I’ll here use the long dimension of your viewfinder, sometimes called the “horizontal” field of view.

A formula for deriving magnification is: M = S/F Where: M = magnification; S = sensor width; F = horizontal field of view

On your Canon 550D, the sensor is 22.3mm wide x 14.9mm high. So in the case where a 2.5mm object fills your sensor, it would work out as:

M = 22.3mm / 2.5mm

Therefore M = 8.92. Carrying this to two decimal places implies more precision than is appropriate, so it would be best to simply say in this case that you are working at around 9x magnification. (But since you said that a 2-3mm object fills the frame, this would actually be from around 7.5x to around 11x magnification.)

In the case where a 5mm object fills up ¾ of your sensor, it would work out as:

M = (22.3mm x ¾) / 5mm

Therefore M = 3.345. Again, let’s drop some insignificant figures and say you are working at around 3x magnification.

Cheers,

--Chris S.

--edited typos

[rjlittlefield]

Chris (chrisiieeg),

As Chris S. suggested, I'll move your thread after you've had a chance to respond to this reply. In concept at least, the FAQ forum is intended to provide reference material, rather than individualized answers.

Let me tackle some of the questions you've raised.

Eg. no point spending big $$$ on MPE-65 if the novelty would just wear off quickly. I could do “just as good” more cheaply (well, maybe not as good, but closer).
....
I would like to expand into area of micro (DSLR+objective lens. **10x magnification to start with).

Good choice. Even an inexpensive 10X objective will blow away the MP-E 65 for resolution at 10X (2.23 mm across the field on your camera).

Q1. Does that explicitly mean if I tried use a 160 finite objective + tube lens (Tamron) set to 150mm, I will not get any usable image (if any) ?
- If I can, then how decent an image do I get? pros/cons?

You will get an image, but not nearly as good as if the objective had been used as intended. See HERE for an example. The two objectives tested there perform about the same when each one is used as intended: the CF N on empty extension, and the CFI with a tube lens. But put the CF N on tube lens, or the CFI on empty extension, and their contrast and resolution go way down.

Q2. Regardless of finite/infinite setup I go with, would I have greater difficulty with stacks than with my setup (B) due to its high magnification?

Yes, you will have greater difficulty. The issue is not really magnification; it's aperture width. Your reversed combo gives a maximum magnification of 250/18 = 14X, actually more magnification than you would get with a 10X objective. But a typical 10X NA 0.25 objective will have much wider aperture, which results in both higher resolution and much less depth of field. To get clean stacks with a 10X objective, you need focus steps that are reliably no more than 0.01 mm or so.

Hence, with 10x objectives, is it advisable to not even try without considering a better focus rail equipment?

Correct.

o Q3. Are the above objectives even close to what I need ?

They're not very good for what you want. The problem is working distance. Measuring from the image posted on eBay, those objectives are almost 45 mm long, and 45 mm is exactly where they will focus. Those objectives are designed for use in a microscope with illumination coming through the subject from behind. They do not provide enough working distance to illuminate from the front.

Does that mean I need a metallurgical objective ?

No. At 10X and below, it doesn't really matter whether the objective is designated as "metallurgical" (that is, specifically designed for use with no cover glass). What does matter is that the objective provides enough working distance (in addition to not requiring "compensating" eyepieces, and providing a sufficiently wide field).

You may have noticed that we've gone to a fair bit of trouble to identify specific objectives as "known good". There's a reason for that. Most of the others that are routinely available have been tested and found to be not so good in one way or another. At 10X, the Nikon CFI BE (infinite) and the Nikon finite conjugate sold by Edmund sell new for less than $100 and are known to be good performers. I have actively searched for other 10X objectives that are routinely available and would be cheaper and/or easier to get, and I haven't found any. There are definitely some others that turn up on eBay from time to time for less money, but it's pretty much like throwing dice unless somebody recognizes the lens and knows that it actually does work OK.

The adapters that you've identified would be suitable for sticking a Nikon CFI BE objective on the front of a telephoto lens with filter diameter 72 mm. Is that what your Tamron 18-270 takes? If so, then be aware that in general zoom lenses work well behind infinite objectives only when they're zoomed to their long end. Otherwise you're likely to get vignetting. I don't recall seeing a report of using the Tamron 18-270 as a tube lens, so I don't know whether it works OK or not.

--Rik

[Chris S.]

Chris (chrisiieeg),

I was writing more as Rik posted. We were saying much the same things, but as usual, Rik was saying them better than I. So I hit the delete key.

Note that for your setup B, Rik calculated your magnification based on your report of your stacked lenses’ settings (quite a valid approach). I calculated your magnification based your report of the frame-filling subject width. There is nothing wrong with either of these approaches, even though they reached different numbers. The differences may lie in the fact that camera lenses are often marked with false, exaggerated focal length ranges, presumably for marketing purposes. In many cases, the exaggeration is egregious. Or the reason may be that your measurement was quick and approximate (which probably suited your needs at hand). Suffice it to say that with a careful test, you can easily determine the magnification you are getting.

You asked what to buy for better equipment as your magnification goes up. A StackShot rail and controller from Cognysis constitute the straightforward answer. They may not seem cheap, but are actually quite inexpensive for what they do, and should hold their value on the second-hand market if you decide to sell later. Note that there is a second-hand specimen right now on our equipment exchange forum.

I’d strongly agree with Rik’s comment that the objectives you linked to would be highly unsuited to your plans, and this is what was prompting me to write you another post. Aside from the utter lack of working distance and the lack of positive prior review, one objective was finite, the other infinite; in a early and frugal setup, you probably don't want a mix of finite and infinite objectives. Lots of us who get really serious use both finites and infinites, but in order to do, we also invest in ancillary equipment to handle both types of optics. This would not seem to fit your present frugal model.

And it’s worth repeating that if money is tight, you don’t want to purchase any lens not specifically demonstrated to be useful by members of this forum. If you limit your purchases to these tested objectives, you won’t waste your money on something that won’t work, and if you do tire of photomacrography, a lens known to perform well should sell at a much smaller loss than an unknown lens. Indeed, such a loss tends to be very small. Long-term frugality is different from short-term minimization of spending, right?

Cheers,

--Chris S.

[chrisiieeg]

Hi Rik & Chris.

Apologies for not posting in the right area. I think I got carried away wanting to ask my question that I forgot to check it. .

Also, I am every so gratefull for both your inputs to this matter. Really, I do have a lot more of reading to do. All the time that it would take me to learn what I need to know to start out in micro, will also be the acid test to see if the interest still sticks .

In essence, I think I have to start telling myself to accept the fact that, I manage to get away with taking "decent enough" macros for as cheaply as possible. But my conclusion so from all your feedback, is that frugality will only get me so far. . I need to consider spending money on good equiptment (but not necessarily the best or most expensive), but definately not "cheapo, no-names" stuff. .

300-400 for a 2nd hand StackShot is still abit ex for me. I have seen old micrscope parts (with fine dial adjustments) being used...but that would involved me bolting it to something and I am not very good at tooling stuff. gosh...so maybe StackShot is the way to go.

Maybe I should start planning for how much I can put aside from this years TAX return (but that is another 6 months away....uugghh!).

Ok, I am being long winded now. Thanks again for your time.

Regards

Chris G

[rjlittlefield]

I have seen old micrscope parts (with fine dial adjustments) being used...but that would involved me bolting it to something

Not necessarily. See http://www.photomacrography.net/forum/v ... hp?t=15697. You could go as simple as using a clothespin to clamp a popsicle stick to the stage of the microscope, extending it out where you can hover a camera over it on a tripod or whatever. If you have a vibration-free environment or you're using flash illumination, then surprisingly unstable setups can still shoot good stacks.

--Rik

[chrisiieeg]

I was thinking alittle bit more like the device in the following post. Not sure

- what it is called, or
- how much it costs or
- how to bolt it to my tripod and my camera to it either. (hrmm, or maybe put my subject on it and move the subject rather than the camera)
- or whether this will give me reliable 0.01 mm increments (as u were mentioning Rik)?

I guess like Chris S. mentioned too that " Long-term frugality is different from short-term minimization of spending?".

That said, I should just spend the right money (not too ex. but not crap either ) and buy proper equipt, say, 10X Nikon CFI BE. That, + my two adapters (72->52, 52->RMS) + a "hopefully not too expensive" rail adjustment (below), then I am all set and ready to go (more or less) ? Yes ? .

I am happy not to go auto (StackShot) at this point in time. Though, still trying to be frugal, are there alternatives to these fine rail adjusters (which seem to look like old microscope parts ), that also provide micro adjustments ?

Again, thanks heaps guys for your valuable time and input. Really appreciate it .

Regards

Chris G.

P.S. were you going to move this post to another area (as u mentioned)? was just wondering . Cheers.

http://www.photomacrography.net/forum/v ... hlight=rig

[rjlittlefield]

I was thinking alittle bit more like the device in the following post. Not sure

- what it is called, or
- how much it costs or
- how to bolt it to my tripod and my camera to it either. (hrmm, or maybe put my subject on it and move the subject rather than the camera)
- or whether this will give me reliable 0.01 mm increments (as u were mentioning Rik)?

The device you've shown is called a "focus block", and indeed it is a a microscope part. These are excellent stacking devices, typically capable of 0.002 mm per tick mark and 0.001 mm with a half tick or less if you're careful turning the knob. Cost is around $100 but varies significantly depending on exactly what you get and how long you're willing to wait.

In the exact picture you've shown, the BHMJ focus block is fitted with a custom adapter plate (the shiny aluminum-looking block) and then with an Arca-Swiss compatible clamp sold by Really Right Stuff. That combination mates nicely with camera, bellows, etc. that are equipped with Arca-Swiss compatible plates. (There are a lot of manufacturers that make mostly compatible parts to the Arca-Swiss standard.)

If I had to guess, I'd say that probably the shiny adapter plate has two sets of holes: one bored through to match existing threaded holes in the focus block, and a second set threaded to match through-holes in the A-S clamp. Unfortunately getting all this stuff fastened together often calls for a bit of machining.

P.S. were you going to move this post to another area (as u mentioned)? was just wondering .

Yeah, but I'm not quite sure where it would be best in the long term. For the moment, it's not hurting anything where it is so I'm being lazy...

--Rik

[chrisiieeg]

Hi Rik.

Wow, quick reply .

.....cost is around $100 but varies significantly depending on exactly what you get and how long you're willing to wait.

Nice ! . I could live with that .

... Unfortunately getting all this stuff fastened together often calls for a bit of machining.

ugh!...was afraid you were going to say that. I guess this means there isnt much out there in way of alternatives to using focus block (and still have micro-adjustment ability) ?

I need to do more reading and looking around on the forum and ebay etc .

Thanks Rik

Cheers

Chris

[rjlittlefield]

I guess this means there isnt much out there in way of alternatives to using focus block (and still have micro-adjustment ability) ?

Consider this approach: http://www.photomacrography.net/forum/v ... hp?t=15697. You can even go as crude as fastening a popsicle stick to the stage with a binder clip, cantilevering it out the side of the microscope to a place where you can hover a camera over it. But the approach shown as a clear plastic box could even be implemented with high quality cardboard and it would work fine.

--Rik

[Craig Gerard]

Chris G,

Not all microscope focus blocks are created equal....if venturing down this path you'd basically want one capable of delivering 25mm of travel for both the course and fine focus. Some scopes offer very little travel in the fine focus department.

Rik's suggestion does present a reasonably accessible means by which to address your initial 'adjustment' requirements and could possibly fulfil your long term intentions; many of the more accomplished members on this forum use such an approach.

Keep your eye on eBay Australia for a microscope base, microscope stand, etc. Olympus CH or BH series stands do appear from time to time.
There is a Zeiss on there at the moment, but I am unfamiliar with its course/fine focus capabilities. The same seller had a 'less complete' stand listed recently at $149.00 (see forum link below, associated links and comments by Pau). I'm unsure if it sold or whether he still has it available. I did make an enquiry about that item and the answer I was given tended to indicate he has more in the 'shed' than just those items listed on eBay.

The course and fine focus mechanisms are precision components of any microscope, sometimes, after heavy use and/or lack of service, the gears can be somewhat other than optimal, so consideration of this factor is recommended if purchasing such a device is your intention.

http://www.photomacrography.net/forum/v ... hp?t=18685


Ernie's approach at the link below presents another possible configuration (but not for the aforementioned Zeiss due to its 'curved' design):
http://www.photomacrography.net/forum/v ... p?p=120839



Craig

[Chris S.]

Chris G,

The microscope focus block you linked to in Noah's rig is an Olympus BHMJ model, which tends to be more expensive than other microscope focus blocks because it is a discrete component that does not have to be cut out of an old microscope stand to be integrated into a macro rig. While the BHMJ units are quite nice (I have a couple of them myself), they are not the only game in town, nor often the least expensive option.

Old Nikon Labophot and Optiphot microscope stands have two-micron per tick precision (identical to the Olympus BHMJ), and are often available at modest cost on eBay. However, before purchasing one, it's very important to ask the seller to verify that both the coarse and fine adjustment knobs operate smoothly through their entire range. Many old stands have problems with the focusing mechanics, and you don't want to purchase one with problems.

I'd strongly urge you to not reject doing light machining. It's actually pretty easy to do yourself, and can also be inexpensive to have done by a professional if you look around a bit. This kind of work is not high precision fabrication, which can take substantial time and equipment and be expensive. Rather, you are purchasing cast-off high precision parts and asking a fabricator to make simple, inexpensive adaptors. Any competent fabricator can cut a piece of aluminum, drill holes in it, and add threads to these holes (that is, "tap them") with ease in a short time. To find such a person, look up "welder" or "welder/fabricator" in your area. My fabricator, Don Wilson, not only turns out excellent work at fair rates, but is a highly valued collaborator in my designs. He will work with you long distance if you want (I'll include my signature so that you can get his contact details). But--though I value Don Wilson very highly--I'd recommend you find someone like Don who works close to where you live. If you can find yourself a local Don Wilson, you'll find it very freeing--simply imagine some optical gizmo you'd like to have, source a few cast--off parts, and your fabricator will quickly turn them into the photographic objects of your dreams. Heavenly--and not nearly so expensive as many people think.

You can also learn to do light, less-elegant fabrication yourself from Youtube videos--and the needed tools are surprisingly cheap. For what we're talking about, you need a hacksaw, a file, a drill, drillbit, and tap. Nothing prohibitive here. If you didn't care about looks, I suspect you could do omit the drill, drillbit, and tap, and just use some decent two-part epoxy. This sort of thing doesn't have to be expensive.

Cheers,

--Chris S.

[Fredlab]

Hello

Many microscopes with one coaxial fine focus knob are OK for stacking.
But some of them have limited travel (Zeiss West - often 2 mm).

Old Nikon, Zeiss Jena (amplival, laboval), all Olympus, have "infinite" fine focus.
(recently, I tested some "chinese" microscopes, most of them have also "infinite" fine focus)

The less expensive i found is an Olympus CHC



Olympus BHMJ is very good choice but it's rare and too expensive.

[chrisiieeg]

Thank you everyone again for such great input/feedback/suggestions. I can see from more reading that I have done recently, that I could split up my so called "microphotography project" to 2 parts.

1st, quickest and easy part, is to start of with buying the 2 adapters (72->52mm, 52mm to RMS) and a Nikon 10x CFI BE objective that I need. I can start playing with this setup straight away. Getting used to how much different it will be (if at all) taking pictures through an 10x objective (what i can and cant do, and with all that I currently have in equipt, in all aspects of lighting, dof, whatever, etc, etc.)

2nd, will be a long(er) term project, of continued research (and thought for what I would like to see as a focus platform etc).

Its refreshing to see the ingenuity of most very serious individuals in creating something to suit for the own purpose and personal style and flavor they have put into it. Some of which I might add, will turn you so "green with envy". haha . Some, I wonder, may even be "overkill".

Regardless, I believe this is an interest that I should be able to stick to . "Over frugality" has cost me so many other hobbies in the past, and I hope to stick with this one. You only live once, so, ...... carpe diem .

Regards

Chris

[Chris S.]

. . .Some, I wonder, may even be "overkill." . . .

. . .so many other hobbies. . . .

An astute observation, Chris G. I think a big difference boils down to whether one considers photomacrography a hobby or a contribution to one's life's work. For me--hopefully--it's the latter, so I wanted a serious, research-grade instrument with refinements to permit rapid, high-quality throughput, repeatable results, and quick shifts among subject types, lighting approaches, and optical regimes. I wanted to incorporate solutions to problems I'd found common in high-magnification photography. Some of these problems, a newcomer might not yet have encountered; a solution to a problem one has not encountered often seems like unnecessary complication.

And if you build an instrument unlike anyone else's, you may get to see things nobody else has ever seen. What can be cooler than that? I love being a collaborator on research teams, acquiring images that help figure things out. Admittedly, I also like making attractive pictures, but helping to answer questions and see things for the first time is--for me--much more exciting. This is most of what I do with the Bratcam.

At the point where you are now, nobody should be pushing you to move from "hobby" to "obsession." If such a change does come over you, it will be spontaneous and come from inside yourself.

Rather, I think think we are encouraging you to obtain equipment that will make the hobbiest level rewarding, rather than frustrating. And equipment that, should you later choose to sell it, will return most of your investment. A cheap lens that nobody here uses, or a poor-quality macro slider, will be both discouraging to use and difficult to sell later. On the other hand, a lens widely appreciated by the macro community, a StackShot, or a decent microscope focus block at a fair price will always attract interested buyers. If you purchase your copies of well-regarded items reasonably, and then find that macro is not for you, you should be able to sell these items back into the community at reasonable prices, with little harm done to your bank account. And with quality items, you'll have given photomacrography a reasonable trial as hobby, rather than a nearly guaranteed exercise in frustration.

Cheers,

--Chris S.