Macro-photography

[Nicholas FarrParticipant @nicholasfarr14254]

Hi MichaelG, thanks, it was a challenge and I thought of changing the subject, but I don't like such things beating me, although I nearly gave up.

Regards Nick.

[MikeKParticipant @mikek40713]

Nice snowflake photos. Scientific American should have done more research, though, as there is a snowflake expert who can design them in the lab, to order. And make two alike. See video below. "Still mystifies" is the wrong phrase for the title. "Still amazes" is more appropriate.

[DiogenesIIParticipant @diogenesii]

That's a great video, thanks for the link

[peak4Participant @peak4]

I was going to add this to the What I Did In The Workshop thread, but having taken a photo, I'm not exactly proud of the workmanship.

I picked up a Moore and Wright electronic "dial" indicator as a good deal off eBay, but it came without a tip.
I had some 4.5mm stainless kicking about, but it's horrible stuff to machine.
The thread is 2.5mm with an 1/8" ball bearing pressed into a 3mm hole in the end, and then rounded over to retain the ball.
I could see the knurling was dodgy, but it was getting late, so I carried on anyway.

Olympus E-M1 Mk2, 60mm macro, MC-2.0 teleconverter + 2 x 10mm extension tubes
15 raw shots, stacked in camera, to give this as a jpg, with no further enhancement or cropping.
At its closest focus distance, the threaded part just about filled the frame.

Bill

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, good shot Bill if nothing else, but the tip looks as it will work. Never mind the quality, it's a good item to photo up close.

Regards Nick.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, the stereo pair shown below are not really macro photos, the pair was taken with my Conon 400D and 40D, each with an EF-S 18-55mm 3.5-5.6 lens and were mounted in the portrait position with their base facing each other on a bracket that I've made for this purpose.

The bracket is yet to be finished, as at the moment each of the L sections that hold the cameras have just a bolt with a standard nut, holding them in place, which having to use two spanners for adjusting each camera position, makes it little long winded and difficult, but I wanted to try the concept out before proceeding any further in case it didn't work satisfactory enough. Have two different cameras also made things a little challenging as some of the settings differ in their execution and after some trial and error, plus the colour tones in each of the two photos is also different, but I believe I've produced a satisfactory stereo pair. The top one is for parallel viewing and the bottom one for cross viewing.

Regards Nick.

Edited By Nicholas Farr on 24/04/2022 19:59:02

[Sam StonesParticipant @samstones42903]

Hi Nick,

A great idea and setup.

Just one problem. As a 'cross-eye' viewer, and unless my eyes deceive me, both pairs are identical.

I switched the lower pair (L to R) in Photoshop and (for me) they looked 3D.

I could be wrong.

Sam

[Sam StonesParticipant @samstones42903]

Back again Nick.

This was the (L to R) switch I did. Hope you don't mind my leaping in here.

Sam

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Sam, the two photos are different, but not by a lot. To me viewing the parallel one, the chairs and table stand out well and in cross view they look a bit mixed up from front to back, just as nearly all cross view ones do. As this is still in a trial stage and the two cameras are different models, I haven't expected them to be perfect and I probably need to turn them slightly more to each other, but I have bought another Canon 400D camera off ebay which should arrive later this coming week and once I get so I only need to use one spanner for adjustments, it should be easier to set each camera up.

Regards Nick.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Sam, I have no problem with you leaping in and I have to apologize, as I have submitted two parallel views in my post above and I should have posted this cross view one. Guess I hit the wrong photo the second time.

Regards Nick.

[Sam StonesParticipant @samstones42903]

Hi Nick,

Sorry if I appeared picky, I didn't mean to be.

I certainly look forward to your next steps with identical cameras and lenses.

Then after that … dare I say … synchronised shutters?

Your a man after my own heart.

Cheers,

Sam

[Sam StonesParticipant @samstones42903]

Thanks Nick, you've made an old man happy.

By the way, I tried to balance the pairs for colour and contrast in Photoshop (CS3), but got myself hopelessly lost.

"Could try better!" comes to mind.

Cheers,

Sam

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Sam, you were not being picky, it was my mistake that I didn't notice. Both shutters were on self timers and pressed at the same time and I couldn't distinguish any lag between the count down beeps or one or the other cameras shutters starting and stopping. I tried balancing the colours in a previous shot or two, but they just wouldn't work.

Regards Nick.

Edited By Nicholas Farr on 24/04/2022 21:42:03

[Joseph Noci 1Participant @josephnoci1]

I really battle to do parallel view – cross is no problem – takes 1/2sec with almost any set of photos. But Parallel….I find the closest I manage is by making two 2cm holes in an A4 sheet of cardboard, spaced my eyes apart, held at my nose and view the two photos through the holes, really close up – say 10cm from the screen – its all blurry then, but easy to keep eye sightline straight. Then I move my head back and try to keep 'blurry', moving till the images start to focus. There are moments when suddenly the 3D pops through and then I loose it and my focus goes crosswise…My eyes just want to do the cross thing..

[Sam StonesParticipant @samstones42903]

Spot on for me too Joseph.

‘Locking in’ (cross-eyed) is almost instantaneous and focusing is not a problem.

I’d say (from my perspective), it comes from viewing those “Spot the difference” cartoons and seeing the differences flicker as (I presume) the brain switches between left and right.

If one frame is above the other, it's necessary to turn the pair through 90 degrees.

That kind of gives the game away.

Sam

PS – There is a down side for some. Feeling nauseous. 

 

 

Edited By Sam Stones on 24/04/2022 22:47:01

[Peter GreeneParticipant @petergreene36336]

I recently built a stereo camera based on Raspberry-Pi. Like this:

Being home-built it's susceptible to modification and I keep wondering whether it would be possible to come up with a macro version. Trouble is that, assuming the generally accepted 1/30 of the object distance for the lens separation would give a figure of only 0.2" for a 6" object distance and quite obviously couldn't be done directly.

I've mentally toyed with the idea of pointing the lenses towards each other and using some kind of prism or mirror arrangement between them that could effectively get me a smaller separation but it doesn't really look promising.

I'm no optics expert though, so if there's something I'm missing ……

[Peter GreeneParticipant @petergreene36336]

Posted by Joseph Noci 1 on 24/04/2022 22:13:25:

I really battle to do parallel view – cross is no problem

Different strokes. I've never been able to do cross-eyed but have historically had no trouble at all with
parallel (wall-eyed) pairs. Little more difficult these days but that's age related.

I've been into stereo photography for probably 40 – 50 years … I still have an extensive camera and projector collection …. and my recollection (which admittedly might be faulty at my age) is that years ago parallel views were used almost exclusively for free viewing. Probably why I have such difficulty now with cross-eyed viewing. The autostereogram pictures are usually (always?) parallel as far as I know.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter Greene 🇨🇦 on 25/04/2022 01:28:35:

[…]

I've mentally toyed with the idea of pointing the lenses towards each other and using some kind of prism or mirror arrangement between them that could effectively get me a smaller separation but it doesn't really look promising.

I'm no optics expert though, so if there's something I'm missing ……

 

.

The 15° included angle between the tubes of typical ‘Greenough’ stereo microscope works very well.

The brain seems to ‘understand’ that the eye-lines converge when looking very close.

MichaelG.

.

This is very low resolution, but I think it demonstrates the point

Edited By Michael Gilligan on 25/04/2022 08:11:32

[Peter GreeneParticipant @petergreene36336]

Thanks for that, Michael. It's a different concept to what I had in mind (mine was to point the lenses directly at each other with a prisms/mirrors to turn the light 90 deg.) but yours looks eminently more do-able. In fact I have a spare lens plate and, probably, a spare set of sensors so I could make up an extra lens board pivoted in the middle and experiment.

Sounds like fun, thanks again!

[old martParticipant @oldmart]

When I was a kid, I was given a stereo camera with some glass plates of toboggons on the Cresta Run. The camera was made of bakelite with a detachable front which housed the shutters and sliding apertures which were just a set of paired holes. With the front off, the body could be used as a viewer, using the single element meniscus taking lenses. The glass plates were about 4" x 1 1/4" with a pair of 1 1/4" images. The images were monochrome reversal, not negatives. I think the camera was German, and often wonder if it would be valuble now if it had not been eventually destroyed by me.

[Peter GreeneParticipant @petergreene36336]

If you contact the knowledgeable folk at Photo-3D group and describe the camera, they may be able to identify it and possibly give you an estimate of its value (if you still had it).

[Nicholas FarrParticipant @nicholasfarr14254]

Hi old mart, your camera may have had some value, but the glass slides may have been worth more as they probably could have been viewed by other means, the photos on them would also make a difference.

Regards Nick.

[Peter GreeneParticipant @petergreene36336]

Posted by Michael Gilligan on 25/04/2022 07:59:39:

The 15° included angle between the tubes of typical ‘Greenough’ stereo microscope works very well.

Michael, do the lens axes intersect at the focus or is there a slight gap between them at that plane?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter Greene 🇨🇦 on 27/04/2022 01:26:18:

Posted by Michael Gilligan on 25/04/2022 07:59:39:

The 15° included angle between the tubes of typical ‘Greenough’ stereo microscope works very well.

 

Michael, do the lens axes intersect at the focus or is there a slight gap between them at that plane?

.

They intersect, Peter

… I will find you a diagram

MichaelG.

.

Edit: __ This is a useful note by LMscope :

https://www.lmscope.com/en/Stereomikroskope_in_der_Fotodokumendation_en.html

but they are specifically discussing ‘single channel’ imaging.

If you are making stereo pairs, the cameras should each see exactly what the eye would [so you are relying upon depth-of-field]. 

Edited By Michael Gilligan on 27/04/2022 05:34:49

[Michael GilliganParticipant @michaelgilligan61133]

Here’s an example of some vintage Greenough hardware: **LINK**

https://www.micromagus.net/microscopes/zeiss_greenough.html

But a pair of Pi cameras with long-ish lenses should do the job without any microscope optics.

MichaelG.

[Author]

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