The next step

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

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Dave S
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The next step

Post by Dave S »

Having joined this group as a newcomer to microscopy, back in May, I went on to buy a basic triocular microscope, with achromatic objectives.

Having decided that microscopy was a pass time that I would like to pursue, I upgraded to a microscope with Plan objectives, and Kohler illumination. I also purchased a Canon EOS 4000d, it being much smaller and lighter than my EOS 5d MklV, while having an 18Mp APS-C sensor.

I should state that microscopy, and micrography, are to me, fascinating pass times, whereas my photography is my serious interest, as at one time, was astro-imaging. (https://davesimaging.wixsite.com/mysite)

For macro, I use an EOS 5d MklV, and a Sigma EX105 f/2.8 Macro, which is a 1:1 a setup, and will focus as close as 120mm from the subject.

While most all of my macro photography is of live subjecst in the natural environment, I have just configured a macro slide rail system for still object use. (see Photos). The side rail unit was from e-bay, and the rest was DiY.

My plan now is, as the 'Next Step', to move into the realm of extreme macro, using a microscope objective, attached to a DSLR. For this I intend using the APS-C EOS 4000d, and not the full frame 5d4.

From what I have read, and been told, Metallurgical objectives tend to have a greater working distance. Also that a finite 160mm objective is preferable to an infinity corrected type, as they don't require an intermediate lens.

I do understand that as there will not be an eyepiece ahead of the objective, to correct for chromatic aberration, this is something that would have to be dealt with in post capture processing

ImageImage

JKT
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Post by JKT »

Three notes:

Finite objectives are easier, but most of them are older. The best quality current objectives are infinite, though there are some cheap finite gems as well.

Depending on your objective, there may not be much CA to deal with. Some manufacturers relied on eyepiece correction, while others did not. I would not bother with the ones that did.

The stand looks a bit flimsy for extreme macro. Might work with flashes, but likely not without. Extreme macro is pretty unforgiving for vibration.

...and to put it all into perspective: I'm practically a beginner at this myself.

rjlittlefield
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Post by rjlittlefield »

For work with microscope objectives, the key thing I don't see in this setup is some adequate way to do focus stacking.

The DOF of any microscope objective is razor thin. DOF starts at about 0.05 mm for a typical 4X or 5X objective with NA 0.10, and drops quickly from there to about 0.008 mm for a typical 10X objective at NA 0.25. You won't be able to come anywhere close to that using the type of rail shown in the pictures.

Do you have a plan for handling the DOF issue?

--Rik

Dave S
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Post by Dave S »

Firstly, regarding the stability of the stand, I don't need to touch it, or the camera when taking a shot, as the camera will be controlled remotely using the EOS Utility software V.3.0.

I can also use 'Mirror Lockup' to minimise the risk of vibration.

I take on board what you say Rik re the micro movements needed between focus points, and all I can do is give it try, using the 4x objective from my microscope. If it doesn't work, then it only the cost (£12) of the adapter that's lost, and I'll probably forget the idea, and stick to my macro work, and photomacrography.

The depth of field issue would be tackled by multiple image stacking

Thanks both, for your input.

chris_ma
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Post by chris_ma »

Dave S wrote:The depth of field issue would be tackled by multiple image stacking
I think the question is how you want to do exactly that with your setup. pretty much impossible to do the necessary small steps manually.

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ray_parkhurst
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Post by ray_parkhurst »

It would be pretty easy to add manual stacking capability to this system. I'm very fond of the Chinese Z-stages available on eBay. There are 40mm and 60mm types (also larger, but quite expensive) with micrometer height adjusters. The adjustment range is ~10mm, and the micrometers are 10um per tick, though you can fairly reliably adjust them in half-tick increments. They are the best solution I've found for adding precision focus and stacking capability to a vertical setup.

Lou Jost
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Post by Lou Jost »

I think it would help you to carefully study the FAQ section of the forum.

Deanimator
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Post by Deanimator »

  1. The finite objectives, especially the 4x Amscope, are dirt cheap. I have the 4x and a 10x. The 4x is quite good. The 10x, not so much.
  2. Infinite objectives are much better quality and and also usually much more expensive. I'm debating switching to infinite objectives via Wemacro's turnkey solution. My problem is that I'm struggling to find subjects worthy of the 4x finite.
  3. I tried focus stacking with a manual rail off of eBay. It was marginal at 1:1, and I gave up. At 4:1 or 10:1, it'd be hopeless. Most of them don't have easily read scales or click adjustments like a rifle sight.
  4. One of your biggest challenges is going to be lighting and diffusion. Shoot highly reflective objects without proper illumination and diffusion and it'll look like you're photographing radioactive poltergeists. This contributes to unwanted artifacts in your stacks.
  5. I have a Wemacro automated focus rail and swear by it. It's an excellent product with excellent customer support.
Follow Lou Jost's advice and do a lot of reading before you dive in. It'll save you a lot of frustration.

Dave S
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Post by Dave S »

Ok guys, a lot of valuable input here, thank you.

I will consider the options put forward, and take on board the advice given.

Then I can consider whether or not to take a specifically designed mechanical approach, or scrap the idea, and as I said earlier, stick with macro, and photomacrography..

Macro_Cosmos
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Post by Macro_Cosmos »

Replace that flimsy cheapo rail with this: https://www.youtube.com/watch?v=UHSsmG0JaVg
And you're good to go with manual stacking.

It's entirely possible to manually stack for 20x and even 50x, let alone 4x.

Manual stacking gives you more precision, no lateral wobble due to lead screw issues, no backlash, and you will be able to precisely determine the beginning and end point of a stack. You're in full control. Automated methods are only really practical up to 20x. 1um does not cover 50x, a friend of mine does all his 50x stacks manually. The 50x M Plan (not crap SL ver) has a DOF of 0.9um < 1um, recommended 0.5um.

I choose automated stacking because I can get other stuff done in my lab while the photos are being captured. That's really the only advantage of automation here.

MC

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ray_parkhurst
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Post by ray_parkhurst »

Here's an example of the Z-stage I mentioned:

https://www.ebay.com/itm/60-60mm-Z-Axis ... 3747282825

Dave S
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Post by Dave S »

Some interesting thoughts, and 'links' there guys, thank you.

The T2 to RMS adapter arrived today, so I took the 4x objective from the microscope, and attached it to the camera.

I managed to get a focused image on a flat subject, using my macro rail system, but it was a bit fiddly, so taking multiple images for stacking, would be a bit of a pain.

The 'cheapo' slide rail works perfectly fine for normal macro work, but yes, it won't do for extreme macro work, I can see that.

Deanimator
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Post by Deanimator »

Dave S wrote:The 'cheapo' slide rail works perfectly fine for normal macro work, but yes, it won't do for extreme macro work, I can see that.
I use mine mostly for fine focus in single image still life photography. For that, it works very well.

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ray_parkhurst
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Post by ray_parkhurst »

The way you have the system configured, the slide rail should be good for coarse focusing, ie getting within a few hundred um of the final focus. Then some other method will be needed to dial-in critical focus, and to make the necessary small and repeatable steps for focus stacking.

Lou Jost
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Post by Lou Jost »

I sort of agree and sort of disagree with the recommendation to do manual stacking, It is tedious and error-prone, and there is usually something more interesting you could be doing (like processing the previous stack). But it is true that many off-the-shelf rails have issues and limitations. My favorite solution by far is to use a microscope focusing block with a fine-focue knob, which I turn not manually but with the wonderful MicroMate from WeMacro.

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