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636 Microscope LEDs & Shut Off/Unplug
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Please be positive and constructive with your questions and comments.

636 Microscope LEDs & Shut Off/Unplug

by baumgrenze on Thu Apr 14, 2016 1:15 am

I tried to Google search site:adafruit.com 636 microscope shut off. One hit seemed germane but was mostly about the Apple interface.

I am using the 636 under Windows 10 (wife's machine) and/or Windows 7 Pro/x64 (my machine.)

The 'manual' is ambiguous (to be generous.) One needs the forums to learn how to control the LEDs. On my 636 I can rotate the control from bright to dim, but once it is plugged in the LED's are 'on' and do not turn off.

The manual reads: "Safety. Do not unplug the Microscope from U B port when LEDs are on. This may cause information loss or circuit damage." This constitutes a Catch 22, Yosarian! Please always close MicroCapture and then unplug the Microscope."

Do both instructions apply or just the last?

Others have observed that to focus at 200x, the 'camera lens' needs to be closer to the object being viewed than is allowed with even the short 'protective ring' in place.

This seems like a major design flaw. How can one examine a 3-dimensional object, for example, a bug, and see anything but the uppermost part of the object without having the 'camera lens' closer to the object than the upper most part. For example, the wings of an insect must 'push against the camera lens' in order to get the body (further away) to come into focus. This seems to my mind a fundamental optics failure.

The student microscopes I used in 8th grade in 1953 had no problem focusing on a all parts of a fly. Granted, they didn't have a CCD to feed a computer via a USB cord.

Please explain.what I'm misunderstanding.

thanks

John

baumgrenze
 
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Re: 636 Microscope LEDs & Shut Off/Unplug

by adafruit_support_mike on Fri Apr 15, 2016 4:06 am

The LED ring is a simple on/off device. The control wheel adjusts the focus.

The transparent standoffs at the end of the scope are a convenience, not a necessity. They make it easier to set the microscope down on a flat surface and observe something small enough to fit in that space. If that's not how you want to use the 'scope, don't use a standoff.

Fair warning, depth of field is inversely proportional to magnification on any lens-based optical system. If you take the magnification up to 200x, changing the distance between the specimen and the microscope by a tenth of a millimeter will throw it completely out of focus.

You'll want the intensity of the LED ring for higher magnifications.. at 200x, the same amount of light has to span 40,000 times as much area.

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Re: 636 Microscope LEDs & Shut Off/Unplug

by baumgrenze on Sat Apr 16, 2016 1:02 am

Thank you for your prompt and informative reply.

The control wheel does have a 'click switch' at one end of its rotation. As it barely projects above the barrel it is a bit hard to turn, especially to get it to turn off.

I've seen responses on this forum inviting customers to return non-functioning microscopes for functioning ones and/or a refund. Do you send the bad ones all the way back to China for a refund to you?

I ask because I would like another 'barrel clamp' or the C shaped bit of plastic that screws to the stand. I have a very stable micropositioner that I could use to adjust the focus in very small increments without otherwise changing the orientation of the microscope. If I take multiple images, I understand that there is software to combine them to get a remarkable depth of field at high magnification. Certainly I can, with enough effort, construct my own 'barrel clamp' but if you just trash the ones that are returned to you with nonfunctional microscopes I'd be glad to pay shipping to have one sent to me.

Thanks

John

baumgrenze
 
Posts: 6
Joined: Sun Jan 31, 2016 9:36 pm

Re: 636 Microscope LEDs & Shut Off/Unplug

by adafruit_support_mike on Sun Apr 17, 2016 1:51 am

We don't send the bad ones back, but we also don't keep spare parts. Given the amount of hardware we move, we can't afford packrat tendencies.

You might want to try some low-temp thermoplastic to make a retaining clip: https://www.adafruit.com/products/2504 It's pretty forgiving stuff, and you can embed things like screws, nuts, and wire for structural strength.

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Please be positive and constructive with your questions and comments.