Perfect alignment, how?

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

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elf
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Joined: Sun Nov 18, 2007 12:10 pm

Post by elf »

I should have asked, how are you shooting each frame, moving the camera/lens orthogonally or rotating around the entrance pupil?

Smokedaddy
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Post by Smokedaddy »

No, just a flat plane panorama. My example grid really wasn't a accurate representation. I'm shooting 'stacks' in each grid section, then processing that stack. Then overlapping about 1/3 for the next grid section stack. Maybe I should of called it a mosaic. I do that a lot with Lunar images too. The camera is an old 50D. I don't move the camera, only towards to wafer. The specimen stage moves and does all of the manipulation. Sometimes I'm using a MPE, Canon MacroPhoto or a reversed enlarger lens. Getting the sensor parallel with the wafer or die in this case saves me a TON of images in each stack. I don't have a current pic of my horizontal rig but it looks something like this. I"m modifying the way the camera physically mounts. I'm still learning/experimenting and haven't nailed the procedure down yet, especially actually making the mosaic.

Image

Image

-JW:

genera
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Location: California, USA

Post by genera »

lonepal wrote:How to be sure that our camera, tube system, lens and carrier rail is absolutely straight and moving absolutely straight?
Bubble level? Laser? or just make a stack and see?

How to detect it without taking many photos?

I need a simple but effective advice.
With your setup as described and without stacking I don't think you'll see an error except possibly for a small amount due to rails that aren't absolutely straight. You'll always be pointing at the same target area, within the straightness limits of your rails.

If you change your setup to make the camera stationary and move the target instead you'll see the targeted feature move across the image if the optical axis and rail axis are not aligned. You could possibly do this in live view or if that's not available, by taking two photos some distance apart and comparing the position of your targeted feature within the photos by using an animated gif with the images superimposed.

Of course, this only gives you information about the alignment. To correct it You would have to be able to rotate the subject rail, probably both horizontally and vertically. You could do this by trial and error with shims under the corners but you would need to be very close to the final alignment before starting. An easier way would be to add goniometers or a tilt/tip stage under your target rail.

After doing this the stage and sensor would be parallel. To make them parallel and concentric you would need two more stages, one for vertical and one horizontal translation. These stages could be under either the subject or the camera.

Once you install the vertical and horizontal stages you could compare focus at the corners of the subject and use tilt/tip axes to equalize the focus in each corner as Rik suggested. No photos required in this case.
-Gene

JH
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Post by JH »

If this is a onetime alignment and It is possible to place a small mirror where the chip is supposed to be you could remove the camera, place a laser pointer “far” away on a tripod and then adjust the reflection so it hits the laser pointer. Try every corner of the mirror.

Best regards
Jörgen Hellberg
Jörgen Hellberg, my webbsite www.hellberg.photo

elf
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Joined: Sun Nov 18, 2007 12:10 pm

Post by elf »

You might try something like this to mount your chip on.

Front surface mirrors are pretty inexpensive from Surplus Shed.

GaryB
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Post by GaryB »

I was just about to suggest mirrors, they seem like the most obvious and accurate. If you can get a mirror with etched markers, even better.

JL
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Post by JL »

Certainly, I do not know your requirements or magnification needs, have you try a microscope calibration slide? something like:

https://www.ebay.com/itm/1pcs-Microscop ... Sw4GVYTVqx

If you manage to get the whole image in focus I guess you can infer that your sensor and subject are parallel

ChrisR
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Post by ChrisR »

I found a way by accident - and since wondered about it.

I was trying to get a microscope slide parallel to the sensor. The slide was mounted on a blob of blu-tak. (Like Plasticene if your locality doesn't have it).
Long story short I ran the objective onto the subject, which "flattened" it nicely.

I have since used an old credit card with holes punched in it so a ring of plastic pushes against the metal periphery of the objective. The force required is very low. As many objectives are concave, a whole, unholed credit card ( or similar) against whatever is forward-most on the objective, may be quite safe.

I've wondered, about using a 3D printed spacer-sleeve, or using a scrap/empty lens, for the same purpose, before swapping to the one I'm using.
Chris R

GaryB
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Joined: Fri Jul 29, 2016 12:18 pm

Post by GaryB »

Wouldn't all this be much easier done on a microscope?
Looking at all these complex contraptions, it just seems like a microscope already has all the functionality necessary, including xyz and alignment for this work. What am I missing? :?

Smokedaddy
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Post by Smokedaddy »

GaryB wrote:Wouldn't all this be much easier done on a microscope?
Looking at all these complex contraptions, it just seems like a microscope already has all the functionality necessary, including xyz and alignment for this work. What am I missing? :?
As for me, in most cases I totally agree. I've made a few dovetail by reversed enlarger lens adapters for my MM-11, plus I have nikon tilt/tip interferometer stage for alignment issues. However in some cases I want to use my Canon Macrophoto, MP-E lens or others on my horizontal rig setup.

-JW:

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