CANON EOS M6 Mark II

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

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MacroLab3D
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Post by MacroLab3D »

I am looking for interesting motives through 10X for example and i like it. Good. Now i am interested to go deeper on some specific detail. I am switching to 50X and boom - i can`t find where it was. Laser helps to do that rough search of previous 10X region and then you can finetune it on a monitor using your fancy positioning system. This is essential feature in my case since i am doing it all the time and it is a night mare and i am glad i found that solution thanks to Chris S. Now i simply can`t buy mirrorless even if i like compact format so much.

Laser aiming is essential if you shooting high mags.

Or give me different solution instead.
-Oleksandr

Adalbert
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Post by Adalbert »

Hello Oleksandr,
I am switching to 50X and boom - i can`t find where it was
yes, it is a normal behaviour because of the mechanical issues.
Laser helps to do that rough search of previous 10X region and then you can finetune it on a monitor using your fancy positioning system.
very interesting.

Your rig is not stable enough and during the changing of the lens you move the lens or the subject.
In this case you only have to move the subject to the right position (see specimen holder).
I would like to stress that the precision of the specimen holder is essential.
Please read the threads about the specimen holder. Maybe this solution would be good enough for you.

BR, ADi

Lou Jost
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Post by Lou Jost »

Or give me different solution instead.
That's why microscopes have precision turrets solidly connected to the specimen holder via rigid metal parts. You can switch objectives with a gentle hand action and the center of the new objective' FOV will be very close to the center of the previous one's FOV.

One solution for you would be to use a microscope with turret as the basis for a vertical photo rig.

MacroLab3D
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Post by MacroLab3D »

Yes, and i am afraid laser through the viewfinder is my real solution.
Lou Jost wrote:
Or give me different solution instead.
That's why microscopes have precision turrets solidly connected to the specimen holder via rigid metal parts. You can switch objectives with a gentle hand action and the center of the new objective' FOV will be very close to the center of the previous one's FOV.

One solution for you would be to use a microscope with turret as the basis for a vertical photo rig.
-Oleksandr

Lou Jost
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Post by Lou Jost »

A WeMacro Micro-mate controlling the focus stage of a microscope is actually a beautiful solution, far more stable and precise than most consumer rails, and you really can switch objectives seamlessly. Minimum step sizes are also an order of magnitude smaller than on the normal WeMacro or Cogsys rails. Also, since it is all basically a single chunk of metal, it is more resistant to environmental vibrations than most rigs.

ray_parkhurst
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Post by ray_parkhurst »

A similar statement can be made for voice coil motors as well, at a far lower cost and complexity.

Chris S.
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Post by Chris S. »

Oleksandr,

I strongly agree with you that at 50x, finding the right spot to photograph on your subject can be horribly difficult. Even finding the tiny, in-focus plain is hard at this magnification--and it's even harder at 100x. As you mention, this is why I built the sighting laser and shared it with our community. The sighting laser makes photomacrography far easier in finding and focusing on the subject of interest, and I would not want to work without it. For this reason, I plan to keep using cameras with mirrors for the foreseeable future in the macro studio. (This implementation of laser sighting focus uses the eyepiece of a DSLR; DSLRs have mirrors. Adapting the sighting/focus laser to mirrorless cameras will take a bit of doing. I think this doing is simple enough in concept, but it will probably need some work to implement.)

With mirrorless cameras combined with infinite-type microscope objectives. My original approach of shining a laser through the viewfinder will not work. However, I think it would be possible to introduce the laser beam in the infinity-space between objective and tube lens, instead of shining the laser through the camera's viewfinder. This might be done using a beam splitter, or by dropping the laser into this space for aiming/focusing, then removing it for shooting. These approaches have been in the back of my mind since the beginning. I think it would be less easy to implement than the simple laser sight version for DLSRs, but still doable. Since your query in the original thread on the sighting/focusing laser, I've been working on a thoughtful response, but the conversation seems to be progressing a bit too fast for me to keep up.

In addition to my sighting laser, certain elements of my macro rig help a lot in finding the intended region of the subject at high magnification, and easily obtaining focus. My rig is very solid, so subject placement doesn't change when I switch objectives from 2x or 5x to 50x or 100x.

Further, I've added a wide, very solid, linear actuator made by Velmex to my macro rig, aligned along the optical axis. I've automated this actuator with a stepper motor driven by an Arduino microcontroller. These elements are set up so that when I press a button, my camera, tube lens, and objective move back away from the subject and lighting by an exact, predetermined distance. This distance permits me to change objective lenses without bumping the subject or lighting. Then, at a second press of the button, the assembly returns to its prior, in-focus location. I find this enormously helpful. It allows me to frame a shot with an easy-to-use low-magnification lens, then hit the button and move the camera/tube lens/objective away from the subject, then change to a high-magnification lens, then hit the button and return the rig to where it was before the lens change. It's a huge time saver. I've long been meaning to share this with our community, but posts of this type take a lot of time to create effectively; this post should include a video to communicate well, and my video has sat way too long at the half-edited stage. (If anyone wants to see the half-edited video, PM me.)

Even with the laser sight/focus I use, plus the precision linear slide movement for changing lenses while maintaining framing and focus, I find that workflow still matters considerably. Even if I intend to photograph a feature at 50x or 100x, I initially frame the image at 2x, then move to 5x or 7.5x, then either 10x or 20x, then either 50x or 100x. This moderated progression helps for a couple of reasons. One, as one zooms in, small composition errors at 2x or 5x become impossibly large errors at 50x. So correct these errors at an intermediate magnification can help a lot in bringing the high-magnification image close enough to expectations that it can be adjusted slightly and be ready to go, without the need for wild searching.
MacroLab3D wrote:UPDATE: By the way, that laser solution is not perfect. I am sure it can damage colors of a subject. Simply by laser burnings. No?
No. This laser won't damage your subjects. The laser I specified in that post does not carry much energy. I've accidentally left mine on for months, shining on a subject through a microscope objective. I've seen zero degradation.

--Chris S.

Adalbert
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Post by Adalbert »

Hello Chris,
I press a button, my camera, tube lens, and objective move away from the subject and lighting by an exact, predetermined distance. This distance permits me to change objective lenses without bumping the subject or lighting. Then, at a second press of the button, the assembly returns to its prior, in-focus location
I like it too :-)
But I move the carriage of my rail to the end, it is no problem with TMC5130A:
https://www.photomacrography.net/forum/ ... c&start=45

BR, ADi

MacroLab3D
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Post by MacroLab3D »

Chris, thank you for your reply. I am relieved to know that i am right and that my feels on that goes on par with you, about splitting beamer. I thought about that solution and DSLR system is still the best. You (i mean i am :)) simply can`t make it more convenient than it is already made in camera. So thank you i am definitely going for Canon 90D now. M6II is cool but sorry. Mirror is too important. And i suggest you, Adalbert to say good by to M6II too. You shoot at 50X i know and you need that laser even if you think you don't at the moment.

Also relieved to know that your laser left no damage even after months of shining laser on the subject. This sounds too perfect.
-Oleksandr

Chris S.
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Post by Chris S. »

Adalbert wrote:
Chris S. wrote:I press a button, my camera, tube lens, and objective move away from the subject and lighting by an exact, predetermined distance. This distance permits me to change objective lenses without bumping the subject or lighting. Then, at a second press of the button, the assembly returns to its prior, in-focus location
I like it too :-)
But I move the carriage of my rail to the end, it is no problem with TMC5130A:
https://www.photomacrography.net/forum/ ... c&start=45
Really useful, isn't it? :D Now that my camera moves to a safe place for changing lenses, and returns to in-focus position, I'm very happy with this feature. (Before I built the feature, I strongly felt the need for it.)

Those Triaminics you (and Mike, et al) use certainly look interesting. I added this motorization before Mike published on the Triaminics, so I use TB6600 stepper motor drivers and improved versions of them. Having learned--sometimes through frustration--the ins and outs of the TB6600 series, and having written code for ramping and other things, I'm inclined to continue using them. If just starting out, though, I'd take a good look at the Trinamics.

The linear actuator I use for basic positioning has 15 inches of travel (IIRC), so I don't need to run the camera to the end of it to get enough work room. And then there is the matter of saving time while changing lenses: I usually run the camera 100mm back from the subject, which takes 22 seconds with my motor and driver, including a ramp-up in speed at the beginning, and a ramp down at the end. I could run it faster with increased noise, but since noise is vibration, I avoid it. Could you tell me how long takes to run a certain distance quietly with your setup?

Cheers,

--Chris

Adalbert
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Post by Adalbert »

Hi Chris,

My first controllers were based on the TB6560 but I haven’t used them since I assembled one based on the TMC5130A.
https://www.photomacrography.net/forum/ ... highlight=

My current rail uses the THK KR2001A and Nema 17 with 0.9 degree:
https://www.photomacrography.net/forum/ ... highlight=

THK KR2001A allows the range about 150mm but I usually start the stacks from the position about 50mm from the front. So I have ca. 100mm to the end.
I could run it faster with increased noise, but since noise is vibration, I avoid it.
me too :-)
With the slowest but silent speed/movement (256 micro-steps) the carriage needs ca. 3 minutes for the 150mm.

BR, ADi

ray_parkhurst
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Post by ray_parkhurst »

Adalbert wrote:Hi Chris,

My first controllers were based on the TB6560 but I haven’t used them since I assembled one based on the TMC5130A.
https://www.photomacrography.net/forum/ ... highlight=

My current rail uses the THK KR2001A and Nema 17 with 0.9 degree:
https://www.photomacrography.net/forum/ ... highlight=

THK KR2001A allows the range about 150mm but I usually start the stacks from the position about 50mm from the front. So I have ca. 100mm to the end.
I could run it faster with increased noise, but since noise is vibration, I avoid it.
me too :-)
With the slowest but silent speed/movement (256 micro-steps) the carriage needs ca. 3 minutes for the 150mm.

BR, ADi
You must be far more patient than I am. 3 min would drive me nuts.

Adalbert
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Post by Adalbert »

Hi Ray,
For you one miscro-step (instead of the 256) would be better :-)
BTW, it is no problem; the number of the micro-steps can be changed dynamically by the software.
BR, ADi

kaleun96
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Post by kaleun96 »

Chris S. wrote:Could you tell me how long takes to run a certain distance quietly with your setup?
I'm using the TMC2130 myself (though I should maybe upgrade to the TMC2209 eventually) and can complete about 140mm of travel (35mm to the back, change direction and 70mm to the front, change direction and 35mm to the middle) in about 45 seconds.

It's still not as quick as I'd like, I don't need the speed for anything else except doing these long-travel movements, but it still could be quicker. I'm changing out the Arduino Mega board for the Adafruit Grand Central M4, which gives me an increase in clock speed from 16MHz to 120MHz. I'm hoping that will allow me to get a bit more out of it.

Another option is to go the route of Mike and communicate with the device solely via SPI or UART, rather than just configuring it via SPI and controlling it via STEP and DIR pins. I could also change the STEP/DIR pin manipulation to use PORT manipulation but that wouldn't be compatible with the AccelStepper library I'm using.

Using a RPi instead of Arduino would also allow you to get a bit more out of these boards, though the 120MHz of the Grand Central is likely sufficient.
- Cam

mawyatt
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Post by mawyatt »

Not sure how you've got these Trinamics configured with the Arduino, but the setup I have can travel 100mm in a few seconds. This configuration does NOT use the Step and Dir mode, but the internal control mode where the Velocity Profile parameters are utilized.

Recall doing a demo where the Trinamic (when properly configured) did 1000mm in under 30 seconds from start to stop, yet retained the ultra precision, stability and low noise of the Velocity Profiles.

Edit: This is accomplished by "switching gears" on the fly where the number of micro-steps is dynamically adjusted during transition to allow very high velocity yet retain the precision, accuracy and low noise characteristics. The motor current waveforms also play into this mode, not just the micro-steps, and these motor current profile parameters play a role in achieving the remarkable performance of these Controller/Drivers. This can be seen by monitoring the motor Sine and Cosine coil currents (one of the reasons we developed the Hall Effect Motor Current Sensor). The Trinamic data sheets are full of details and information on these complex controller chips, and they are indeed complex! I know I've spend many hundreds of hours studying and experimenting with them, even developed custom PCBs to evaluate performance!!

BTW I've found that the Trinamic 5160 StepStick has the chip forced (wired) into the Step and Dir mode and can't be easily changed (requires removing the chip and cutting PCB traces and using a tiny wire jumper). Evidently these smaller footprint Trinamic boards are designed to be drop in replacements for the various motor drivers used in 3D printers which don't employ the chip built-in velocity profile modes. Seems silly that this StepStick wasn't designed to be reconfigured for more robust use, but stuck in the Step and Dir mode!!

Best,
Last edited by mawyatt on Sun Jan 05, 2020 7:56 am, edited 2 times in total.
Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

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