2M4P - Two microscopes Four photos

[The QCC]

A paraphrase of the play 2P4H

A curiosity comparison between two microscopes with different cameras and the same specimen.
The microscopes are a Labomed LB-592 and an upgraded vintage Bausch & Lomb.
The cameras are from the same manufacturer, the objectives (PLAN 4x, not interchangeable) are from China. and the specimen (Gabbro) is the same.

It may read like an apples and oranges comparison, but it is more like lemons of different species.

The basic reason for the photos was to check a DIY LED source on the B&L against a Halogen lamp on the Labomed.
Both photos 1 & 2 are white balanced by the cameras, yet the Halogen appears more neutral than the LED. Well it looks cooler.
While the B&L may look sharper, the CA (green) was quite evident.
The Labomed has more detail, but not as sharp.
Only Photos 1 and 2 can actually be compared. They are both with white and plane light.
Photos 3 and 4 were needed to satisfy the four photo thing.

Click to see the photos

Gabbro.jpg (176.89 KiB) Viewed 5419 times

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Details:
Microscope 1: Bausch & Lomb, 4x PLAN obj., Canon XS Rebel (1000D)
Microscope 2: Labomed LB-592, 4x Infinity PLAN obj., Canon 5D MkII
Post processing: Adobe Lightroom.

[gekko]

All very nice, but I much prefer the B&L images (I don't know why, though).

[JimT]

Neat project. To my weak eyes the Labomed image seems to have much more CA than the B&L LED image but much more detail and better resolution. Any chance you mislabeled them or am I wrong?

Also I suspect the two different cameras affected the outcome. Big difference between the Rebel and the full frame 5D.

I'd be interested if you do more testing using the same camera for all images.

[The QCC]

The CA in the B&L, or most of it, was removed in Lightroom.
No CA was removed from the Labomed.
These are the RAW CR2 images resampled down to 640 and JPEG
The B&L has a 10w LED as a light source and the Labomed a 100w Halogen.

Bausch & Lomb

Gabbro1_XSOB_4x_002.jpg (270.81 KiB) Viewed 5409 times

Labomed

Gabbro1_5MLP_2x_100.jpg (372.82 KiB) Viewed 5409 times

P.S.
I will, grudgingly, move the 5D from the Labomed to the B&L and re-run the test.
I will not be changing the light source.
I like fun, but I am not a masochist.

[zzffnn]

QCC,

I guess an apple-to-apple comparison is never going to be fun as it requires scientific rigors and limiting variables down to minimal.

I understand that you are into mineral and fossil. But your gabbro sample is probably difficult to use as a yardstick for comparison. It has too many details and colors on different planes of focus. Your two comparison photos seemed to focus on completely different surface planes (one was focused deeper than the other), and we are seeing different amount of details because of unequal depth of focus.

A very thin/flat mounted diatom may be a better yardstick. It has no color though. And you have to remember what details you saw on which plane of focus to compare two scopes, which would be pain. Sometimes, if you are lucky, you may be able to resolve dot details with one set-up, but not the other - that would make comparison easier.

Also how did you white-balance your LED with camera? Did you use custom white (let yoyr camera see a pure white subject under the same LED light condition and tell the camera "use this as white standard" - this is best with LEDs)? Or did you simply use auto white balance (which may not work well with LEDs, though auto balance is great with flash, sunlight or halogen). You can use Kevin temperature too, if you know the color temp of your LED.

At the same lumen of light output, in theory, halogen should out-perform LED as many LEDs do not produce green light (which is the best performance spectrum for achromat objectives). But most LEDs are much more efficient (so likely brighter) than halogen, so with different amount of light output, it would be difficult to predict and we have to compare case by case (scope by scope and subject by subject).

[The QCC]

The Canon software, EOS Utilities, has a custom white balance function that it stores in the camera. Thus, two cameras, different light sources, separate settings.
The White Balance function is similar to Photoshop's.
Using the EOS utilities, move the specimen out of the light path, remove the analyzer, set the camera's light source colour temperature, use the Utilities custom White Balance eye dropper to sample the light.
Repeat the sample whenever the light intensity is changed.
All of the above settings are performed in the EOS Utilities, you never have to touch the camera.

The comparison was a curiosity thing. Mainly to determine whether I will buy a higher quality Infinity PLAN 4x objective for the Labomed. Comparing photos from two PLAN 4x obj. seemed like a start.
I am considering an Olympus Infinity PLAN 4x Achro. Apos are not an option as they are incompatible with the microscope.

I cannot repeat too many times, I do not take microscope photos for any kind of analysis. The photos I take are invariably used as texture maps, backgrounds or large scale prints.
Or if they contain interesting shapes and colours, this forum.