Fast Stacker (Arduino based automated focus stacking rail)

[pulsar123]

Here is my Xmas present: a new version of the software, s0.14:

http://syam.no-ip.org/stacker_v0.14.zip

Now the rail senses if it is AC or battery operated, and if the latter it will use a slower speed limit (adjustable), to improve the motor's torque. Also a bug was fixed in the "Factory reset" function.

[pulsar123]

Great news! Just in time for the new year, I have managed to do the ultimate hardware modification to my rail (which I already coined "h1.2") - the one where I gained independent programmatic control of both camera's shutter and autofocus - and the rail survived this major surgery, and seems to be working as expected. This new setup should be the most attractive to non-Canon camera owners, as many non-Canon cameras require both the shutter and the AF camera switches to be controlled to do remote shooting. I believe now I can make my focus stacking rail truly universal - should work with any camera model. For Canon camera owners there is less incentive to do the mod, as the only improvement you might see will be slightly faster startup time when doing 1-point stacking.

The software hasn't been updated yet to make use of this new functionality. I will start working on that, and also on updating my wikia tutorial to reflect the hardware and software changes.

Stay tuned!

[pulsar123]

Update [07.01.2016]: I am releasing a new version of my stacking software, which is ambitiously named "s1.00". It is designed to only work with the newest hardware version, h1.2. This new software and hardware should make the rail much more universal: it now independently operates both camera's shutter and autofocus, so in principle should work as is (or perhaps with slight parameter adjustment in stacker.h) with any camera which has a wired remote shutter connector. The modifications will also likely result in faster maximum shooting speeds attained with your camera: e.g. my Canon 50D can now reliably do at least 30 frames at 4 fps (RAW format), without any perceptible delays at the beginning.

My wiki tutorial has been updated to reflect all the changes:

http://pulsar124.wikia.com/wiki/DIY_aut ... on_Arduino

[pulsar123]

I would like to get some feedback here: which functionality is still missing in my focus stacking rail software? I discovered that one of my keys ("*") can be freed up painlessly, as it is currently assigned to the only non-backlash compensated function I have - 1-point continuous stacking towards the camera. Plus, it is not a natural way to do stacking (from background to foreground). Once the key "*" is freed up, I can introduce up to 15 new functions via two-key binding starting with "*". (So "*" becomes sort of Alt key; "#" is already sort of Ctrl key.)

So what is missing? The obvious thing would be to convert some of the constants to user-modifiable (via specific key "*" commands) parameters. For example, ACCEL_FACTOR - can have a few possible values (set to "1" when doing 1:1 macro; use "3" for 2-5:1; use "6" for even larger magnifications). Then backlash compensation can be turned on or off. SAVE_ENERGY can be set to on/off. Perhaps MOTOR_DEBUG can be temporarily enabled (for those rare situations when the software gets confused, and one needs to disable limiters to rewind the rail in the safe area.) AF_SYNC can be set to on or off. The latter would only be needed if you are using two different cameras with the rail - but in this case I think the better solution would be to have a "*" command to switch between different cameras. One can then update stacker.h to assign custom values of AF_SYNC and perhaps some other camera specific parameters to different cameras.

Another thing which is missing is the ability to fully reverse the direction of the rail operations (for example, if with certain macro lenses you need to face the camera the opposite way). Right now, because of the backlash compensation, stacking is mostly done in one direction (positive; from foreground to background). When fully reversed, backlash compensation will work in the opposite direction, so will be the stacking. This could be a bit tricky to implement, but probably worth my time.

After reading the Cognysis StackShot manual (BTW, I updated my http://pulsar124.wikia.com/wiki/Introduction with a long list of the advantages of my rail design over the Cognysis, and the few disadvantages I could find), I found another potentially interesting feature to implement: Time Lapse mode. This will allow to run multiple stackings in a row, for example for flower buds slowly opening. Not sure this is particularly interesting, as it is video not photography.

Anything else?

One more point - I am now branding my project as "Fast Stacker", to set it aside from a few other comparable projects. This is to emphasize that my design is especially optimized for fastest possible stacking, hopefully usable with live insects.

[ChrisR]

Another thing which is missing is the ability to fully reverse the direction of the rail operations

I know some repsected workers always go background to foreground, though TBH I'm not sure why.

I tend to go fore to back. With native Stackshot telling you so little, you don't know how many steps until it's started.
Then at least if you're going fore to back and it's saying 2000 steps to go, you can just stop it when you get bored and still have the fg in focus!

[pulsar123]

CrisR: It's a bit off topic, but I believe I've seen your posts here which imply that you had (or still have) the microscope objective Nikon E Plan 10x/0.25 LWD - is it correct? What is your impression about the lens? On the coinimaging.com test site, this lens is the first to third best lens for magnifications 7...15, only slightly behind Nikon MPlan 10x/0.25 (but it has a slightly longer working distance):

http://coinimaging.com/hall_of_fame.html

It appears this lens is the only quality ~10:1 lens one can find around 100$. I need something like this to push my macro rail into more extreme regime, to see if it can deliver (accuracy etc.) at significantly higher magnifications. (Right now I am only shooting around 3:1, which is 5:1 FF equivalent).

Will this adapter work with this objective?

http://www.ebay.ca/itm/Brand-New-RMS-Th ... xy--NRpu4M

[Pau]

I can't say anything about the objective itself, but the linked adapter is adequate for sure if you have a M42x1 "Pentax screw mount" bellows (T mount is M42x0.75).

It's a bit off topic

Yes, it is. We will move it no a new thread once you have time to read it if you want, this is your thread

[pulsar123]

I can't say anything about the objective itself, but the linked adapter is adequate for sure if you have a M42x1 "Pentax screw mount" bellows (T mount is M42x0.75).

Thanks! I have standard M42-EOS adapters (and an EOS bellow and extension tubes), it looks like it will do the trick.

[ChrisR]

Actually, one of the very few objectives I ever sold! I miss it because it was cheap enough to use as a loupe...
"Not bad" was my impression, though I have other options.
"Long" working distance isn't very long with this one though I forget the number.
There are other options - I'll pm .

[pulsar123]

Actually, one of the very few objectives I ever sold! I miss it because it was cheap enough to use as a loupe...
"Not bad" was my impression, though I have other options.
"Long" working distance isn't very long with this one though I forget the number.
There are other options - I'll pm .

Thanks - I'd appreciate a pm with alternatives. In fact, the lens I mentioned is no longer available, so I'll keep looking.

[pulsar123]

Update [22/01/2016]: I am releasing a new version of my macro rail software, s1.10. (It requires hardware h1.2.) This is likely the most significant single update I ever made to my rail's software. The rail gained a large number of functions (14 new key bindings), including new features like timelapse focus stacking. In a summary, the new version will make my rail much more usable for extreme macro photographers (magnifications 5:1 and up; should be usable up to 20:1), and for those who regularly use a wide range of macro lenses (from standard 1:1 macro to 20:1 extreme macro). The update also significantly improves the user interface, and dramatically reduces the need to recompile the code (all the important parameters can now be changed at runtime). The detailed list of the improvements can be found here:

http://pulsar124.wikia.com/wiki/Whats_new

The software can be downloaded from the above page, or just use this direct link:

http://syam.no-ip.org/stacker_v1.10.zip

Enjoy!

[pulsar123]

For those who decided to reproduce this DIY project: please join my Flickr group "Fast Stacker" ( https://www.flickr.com/groups/2960405@N22/ ), and submit there the photos of your Fast Stacker, and the macro photos made with the help of your Fast Stacker. (Also please post the technical details of the shots - the stacking mode, the flash settings etc.). Let us all learn from each other's experience with this device.

[nsomnius]

Just read through the What's New on the Wikia and I'm more blown away than I was! You're dialing this thing in to an astounding level. My hardware is complete and I'm hoping to have time to work up the circuits soon. Your work is very inspiring and I can't thank you enough for sharing it!

[pulsar123]

Just read through the What's New on the Wikia and I'm more blown away than I was! You're dialing this thing in to an astounding level. My hardware is complete and I'm hoping to have time to work up the circuits soon. Your work is very inspiring and I can't thank you enough for sharing it!

Keep us posted about your progress! Don't forget to upload your rail's photos to our Flickr group.

Is it the same rail and motor as mine, or different? One area where my design might be currently lacking is in its support of different hardware. One very obvious factor you should be aware of is that my current software can only handle rail/motor combination with up to 16,000 microsteps in total (this is sufficient for my hardware). There is an easy fix to expand that to 32,000 microsteps - I will do that shortly, no excuses about that. But going further would require changing all coordinate variables' types from short (16 bit) to long int (32 bit), which might run into memory (flash/RAM) issues. I will experiment with that. If it will fit into the memory, I can simply have a macro constant to set the type (either short or long int) for the coordinate variables everywhere in the code.

[ChrisR]

How does that translate ..
How many microsteps per whole step?


Some rails would be 300 turns, end to end. (eg 30mm/0.1mm),so assuming a 1.8º step that's 60000 whole steps.