Focus-stacking - an idea.

[henrikfoto]

I have an idea for focus-stacking in studio etc:

I would like to use the best lenses which is LF-lenses in electronical shutters and the best camera which is a high res digital back. With a normal Sinar P2-3 I can of course let the front be stationary which is good for stacking.
Just moving the back standard is no problem, but for macrowork the movement of the beck standard is too
unprecise. I would like to move more carefully and in exact same steps every time.

I was thinking how it would be to mount a Stackshot automatic rail on the rare standard.
http://www.cognisys-inc.com/stackshot/2996_Macro-Rail_1000x666.jpg

That is a very precise rail and can move very slowly in small steps.

Has enyone tested this?
Is it hard to do the modifications?

Henrik

[Torbjörn Tapani]

I cannot answer your question but Newport linear stage with a micrometer seem to be popular in the macro community. I saw they have motorized linear stage as well http://www.newport.com/Motorized-Linear-Translation-Stage-Selection-Guide/168479/1033/content.aspx

[elf]

I don't think the Stackshot rail (or any other stage) would adapt very well to the Sinar.  The Stackshot controller however could be used to drive a stepper motor attached to the control knob of the rear standard.

[henrikfoto]

I cannot answer your question but Newport linear stage with a micrometer seem to be popular in the macro community. I saw they have motorized linear stage as well http://www.newport.com/Motorized-Linear-Translation-Stage-Selection-Guide/168479/1033/content.aspx

Thank you for this link!
Very nice equipment. Newer knew about this company.

[Pics2]

I don't think the movement is unprecise with, let's say, Arca Swiss M2 or similar. But, I prefer Mamiya DF plus 120mm macro combo for precise focus stacking work. This lens is up to digital LF lenses standard. I stick to this combo since I have old Cambo LF camera and it's all shaking and moving when I try to adjust focus 

[henrikfoto]

I don't think the movement is unprecise with, let's say, Arca Swiss M2 or similar. But, I prefer Mamiya DF plus 120mm macro combo for precise focus stacking work. This lens is up to digital LF lenses standard. I stick to this combo since I have old Cambo LF camera and it's all shaking and moving when I try to adjust focus 

I have used this combination, but I would like to do more even steps and smaller steps than what is
practical with the DF and manual focusing. And I would like to be able to repeat the staps with the
same intervals.

[Pics2]

I understand, you are right.
If nothing, you can mount this combo (Df body and macro lens) on Stackshot automatic rail, if it turns out to be impossible to mount Sinar on it.

[bjanes]

I have used this combination, but I would like to do more even steps and smaller steps than what is
practical with the DF and manual focusing. And I would like to be able to repeat the staps with the
same intervals.

Here is an excellent article by Rik Littlefield, author of Zerine Stacker, regarding the pros and cons of using the focus ring vs a rail. His example is for the 135 format, but should apply to MF as well. The focus rail is best for extreme closeups whereas the focus ring is better for shots with less magnification and is the only feasible method for most landscape work.

Auto focus is generally not regarded as useful for most macro photography, but it is quite useful for stacking in a macro situation since one can make very small and precise focus adjustments with software control of the camera (e.g. Nikon Control for Nikon and Helicon remote and other solutions for other cameras). I presume similar software is available for MF.

Bill

[henrikfoto]

Auto focus is generally not regarded as useful for most macro photography, but it is quite useful for stacking in a macro situation since one can make very small and precise focus adjustments with software control of the camera (e.g. Nikon Control for Nikon and Helicon remote and other solutions for other cameras). I presume similar software is available for MF.

Bill
[/quote]


I wish this was possible with the Phase One DF, but it's not.
I do this with my Nikon and it works very good.

[Bart_van_der_Wolf]

I wish this was possible with the Phase One DF, but it's not.

Hi Henrik,

Maybe things will change for the IQ250 back. I assume that if someone makes one available to the developers of Helicon Remote, they'd consider adding the functionality for Live View. While it won't allow to remote focus by wire, it would probably allow to use the Focus peaking function which works well for manual focus lenses, and of course it also drives the StackShot rail. When the StackShot is detected it overrides the lensfocusing anyway.

Cheers,
Bart

[jerome_m]

I presume similar software is available for MF.

Phocus does that for Hasselblad cameras.

[henrikfoto]

Hi Henrik,

Maybe things will change for the IQ250 back. I assume that if someone makes one available to the developers of Helicon Remote, they'd consider adding the functionality for Live View. While it won't allow to remote focus by wire, it would probably allow to use the Focus peaking function which works well for manual focus lenses, and of course it also drives the StackShot rail. When the StackShot is detected it overrides the lensfocusing anyway.

Cheers,
Bart

That might be good news, but it will still move the entrance pupil. My hope is to find a
way to keep the front steady and adjust the back standard only with were fine focus like the Stackshot.

[henrikfoto]

Phocus does that for Hasselblad cameras.

I know, but I don't have a complete integrated H.

[elf]

That might be good news, but it will still move the entrance pupil. My hope is to find a
way to keep the front steady and adjust the back standard only with were fine focus like the Stackshot.

(see previous post) Attach a stepper motor to the rear standard adjustment knob.  It shouldn't be all that difficult to do.

[Bart_van_der_Wolf]

(see previous post) Attach a stepper motor to the rear standard adjustment knob.  It shouldn't be all that difficult to do.

Hi,

Maybe, but that's not all there is to it. The gears of the camera rail must also be accurate enough for the required precision and repeatability, and the required torque must be matched to the motor. One also need some sort of controller for driving that stepper motor.

The benefit of the Stackshot is that it can be stepped with as little as 0.000496 mm intervals (~0.5 micron), but slightly larger intervals are a bit more reliable (17 micron is the smallest I have needed at 5:1 magnification factor). It has separate settings for torque and ramp up/down speed, to name a few. But I do not see an easy way to attach it only to the rear standard and aligning the rail with that of the camera, although it's probably doable for someone with an accurate configurable workbench, a CNC machine, or various alumin(i)um profiles and connectors.

I suggest that Henrik  takes a good look at the article by Rick Littlefield that Bill linked to, and see if for the anticipated magnification factor shooting scenarios the perspective issue is really going to be a problem. Being able to pull things off with the Stackshot alone, is a huge workflow benefit and time saver.

The perspective issue is not an issue for many subjects either, but it can be for some. It depends on a lot of variables (like occlusions, and composition, and magnification factor) which is the best route to follow.

Cheers,
Bart

[henrikfoto]

Hi,

Maybe, but that's not all there is to it. The gears of the camera rail must also be accurate enough for the required precision and repeatability, and the required torque must be matched to the motor. One also need some sort of controller for driving that stepper motor.

The benefit of the Stackshot is that it can be stepped with as little as 0.000496 mm intervals (~0.5 micron), but slightly larger intervals are a bit more reliable (17 micron is the smallest I have needed at 5:1 magnification factor). It has separate settings for torque and ramp up/down speed, to name a few. But I do not see an easy way to attach it only to the rear standard and aligning the rail with that of the camera, although it's probably doable for someone with an accurate configurable workbench, a CNC machine, or various alumin(i)um profiles and connectors.

I suggest that Henrik  takes a good look at the article by Rick Littlefield that Bill linked to, and see if for the anticipated magnification factor shooting scenarios the perspective issue is really going to be a problem. Being able to pull things off with the Stackshot alone, is a huge workflow benefit and time saver.

The perspective issue is not an issue for many subjects either, but it can be for some. It depends on a lot of variables (like occlusions, and composition, and magnification factor) which is the best route to follow.

Cheers,
Bart

Thank you, Bart!

I just found out that Someone have had the exact same idea before me:
Michael Ulsaker allready has a Stackshot that is integrated into the Sinar P2-P3!!!

Henrik

[elf]

OK, I'll admit I have a CNC machine and a few other machining tools  
The Stackshot controller is a nice off the shelf solution for stacking and it is capable of controlling stepper motors not attached to the Stackshot rail, which makes it easy to do custom setups.  For reference, the stepper driver on my CNC machine is capable of 25,600 microsteps per revolution, so theoretically it could achieve much smaller step sizes than the Stackshot. 

My focus stacking panorama setup uses a 6mmX1mm leadscrew, a cheap Easydriver stepper driver, and an Arduino to control everything.  It can do 1 micron steps very accurately.

[henrikfoto]

OK, I'll admit I have a CNC machine and a few other machining tools  
The Stackshot controller is a nice off the shelf solution for stacking and it is capable of controlling stepper motors not attached to the Stackshot rail, which makes it easy to do custom setups.  For reference, the stepper driver on my CNC machine is capable of 25,600 microsteps per revolution, so theoretically it could achieve much smaller step sizes than the Stackshot. 

My focus stacking panorama setup uses a 6mmX1mm leadscrew, a cheap Easydriver stepper driver, and an Arduino to control everything.  It can do 1 micron steps very accurately.

If you have the tima I would be very happy to see i picture of your setup.
Is it expensive ?

[elf]

It's on my ToDo list to document my new field setup for focus stacked panoramas   I don't have any decent shots of it online right now.  Here's a link to my desktop setup that works quite well up to 10X: http://www.photomacrography.net/forum/viewtopic.php?t=8348&highlight=pano

[henrikfoto]

It's on my ToDo list to document my new field setup for focus stacked panoramas   I don't have any decent shots of it online right now.  Here's a link to my desktop setup that works quite well up to 10X: http://www.photomacrography.net/forum/viewtopic.php?t=8348&highlight=pano

Amazing!!!
When I see this I understand I have a lot yet to learn.