DIY Stack and Stitch System

Entropy512 wrote:

mawyatt2002 wrote:

Entropy512 wrote:

Nice!

Trinamic stepper drivers have become extremely popular with the 3D printing community.

FYI a similar project hit Hackaday a few days ago - https://hackaday.com/2019/06/14/gigapixel-microscope-reveals-tiny-parts-of-the-big-picture/

Thanks.

The project over on Hackaday is very interesting, great for starters to get involved and seems straight forward.

The wood platforms and the linear rails used will need to yield to higher levels of precision, stability, and repeatability to get close to the resolutions mentioned. Most folks in higher precision and resolution stacking use precision rails and microscope objectives. Also it's usually better to move the camera/lens/subject in the Z axis rather than the usual in camera focus when you move to higher magnifications beyond ~2X for the best IQ. So not only the mechanical, electromechanical and electronics, but the optics can get quite involved. With stacking and stitching then telecentric optics become an important factor for consideration if subject distortion is important.

That appears to be the approach he's using for focus - "The focus was adjusted with the tripod z-direction." - but obviously that wemacro setup looks like it would be much better. I'm likely going to get one if only for film copying purposes. Using a tripod kinda sucks for this sort of purpose.

The HaD guy's approach to telecentricity appears to be to add an additional aperture stop between the main lens and the reversed one in his setup. I'm not sure what the validity of this approach actually is - but it's something I never tried and might explain why I had many weird issues when putting a reversed 28mm lens on a 100mm lens.

Some of the commercial offerings from Wemacro and Stackshot are pretty good for those that don't want to DIY for Z axis stacking, but for very high precision work you'll need to move to the industrial type rails.

You appear to be operating at much higher magnifications than the guy on HaD - but you've got a system that can handle some of those really extreme scenarios without costing much more from what I can see.

Telecentric optics are very interesting, do a search over at Photomacrography site, there have been plenty of discussions on this subject by very knowledgable folks. There's also brilliantly simple test for this as well!!

Placing a aperture between the stacked lens is a very good solution "if" you can get to the right position, often that position is within one of the lenses and thus not realistic.

A 28mm on a 100mm is ~3.6X which is getting into the range where objectives begin to take over with higher IQ. Some aren't expensive like the Lomo 3.7X.

Sometimes not necessarily higher magnifications but higher resolutions. I have a Nikkor PN105 F2.8 1X which is stunningly sharp even at the pixel level, but requires an extremely stable setup. This is reproduction lens optimized for 1X, and kind of a benchmark at that magnification. I use a quality teleconverter (Nikon 1.4 TCIII) to keep the PN105 at 1X but give an overall 1.4X with the converter, it's better this way than moving the PN105 away from 1X to 1.4X because it's so highly optimized at 1X. I have used higher magnifications, like 20X with Mitutoyo with a stack and stitch of some tiny Indium Phosphide chips I designed, but the the bottom line is more about achievable resolution than magnification. Since stacking and stitching are available for serious work I try to achieve the best usable resolution for a given chip subject, then if I can stack without stitching that's good, if not,  then I'll need to stitch.

I just ordered another Vertical Stand from William at Wemacro. These are really good, you will like it for copying and other macro uses. Be sure and get the horizontal option, it works really well horizontally too!!

The cost of the systems range from reasonable to expensive, especially if you count all the developmental costs. Almost all of my precision stuff is DIY with surplus gear, I've even developed my own controllers & motor drivers (some multi-axis) since the commercial ones couldn't achieve the results I was looking for.

Obsession with precision is probably a good assessment 

Best,