Any affordable 1" sensor USB cameras?

[Dubious]

Has anyone found an affordable C-mount USB camera with one-inch sensor? The only ones I've found have been much too expensive for my purposes.

On my Olympus IMT-2, I would like to use a USB camera connected to the side port, rather than the Canon EOS 550D now connected to the front camera port. I have the Olympus MTV-3 adapter with C-mount .3x reducer, which does connect to my 1/2" sensor USB camera, but with the 2.5x photo relay eyepiece inserted in the port, that configuration crops much more than I would like. Per Allan Wood, a 1" sensor is needed:
http://www.alanwood.net/olympus/c-mount ... ml#adapter
I could alternatively use a 1.6x photo eyepiece, but those are rare and grossly overpriced (one is now on Ebay at $900). According to Allan Wood, a Nikon 1 J1 or Nikon 1 V1 camera has an approximately 1" sensor and would work, but while available at reasonable prices, I don't think those cameras can be used with tethering software.

[patta]

Guess:
the 1' sensor was common for CCD in the past but seems almost abandoned, rare today for CMOS.

The most common/affordable 1" sensor today seems to be Exmor R Sony IMX183 20 (or 8) MP, then packaged in a camera by different companies. Cheapest I've seen is 500$, https://it.aliexpress.com/store/1918400 ... 5a08ZY2hiZ. More expensive, better packages and sturdier connectors (maybe?)
https://microscopecentral.com/collectio ... usb-camera
https://agenaastro.com/catalogsearch/result/?q=183c
Disclaimer, I don't have experience with any of the above...

Getting another old Canon APS-C & let the crop be, it is the most affordable large sensor; Micro 4/3 like Lumix or Olympus do not seem to be affordable, and no idea about tethering them to a computer.

Rethinking the adapters train for your 1/2", there may exist the right adapter at reasonable price somewhere, like the one at the bottom of AlanWood link
A macro lens may do a decent job as adapter for the 1/2" (instead of olympus Eyepiece + adapter) but will be a bit tricky to mount it in proper place, collimated and stable, and you lose the eyepiece compensation...

Edit: for the 1/2, you can use it afocal, with a standard C-mount lens, straight in front of the 2.5x photo eyepiece, you just need to find the right focal length so to get desired field. The C-mount lens works just like the Olympus 0.3x, but with 0.1x. Plus mechanical assembly; should stay cheaper than the 1.67x eyepiece.

[Dubious]

Thanks for the links. Edmund Optics also has a selection of 1" USB cameras, but they are all prohibitively expensive. The RisingCam you linked at around $500 does have the features and comes closest to being affordable, but seems available only direct from China. I like the idea of using a USB camera--no clunking mirror, electronic shutter, and total control from the computer--but unless I can work out a better solution for my existing USB camera, will probably stay for now with the EOS 550D connected to the IMT-2's front port. Not ideal (port expects a full-frame camera) but it does work.

[patta]

I've tought about that, and put together today a working prototype for the "afocal with small sensor" as from previous post
viewtopic.php?f=9&t=13456&p=108178#p108178

The RisingCam, I've read some threads from Cloudynights, it seems that they are a real company; and make cheaper versions of the better ones (ZWO, Toupcam, Edmund etc).
They suggest to check the actual specs; the sensor may be the same but to get lower price they skimp on other hardware, like in-camera image processing, noise suppression chips, and proper soldering of the USB plug socket.
So new 1" camera are expensive, no ways around; the Nikon J1 was 650$ new.

[PeteM]

RisingCam on Ebay. They have a few models with various 1" Sony sensors: https://www.ebay.com/str/risingcamoffic ... 7675.l2563

The Nikon J1 has an HDMI output for composing and focusing and is easily connected to a c-mount, but as you say can't be fully tethered.

If 5mp is satisfactory (should be capture all the optical resolution possible at higher magnifications) then the old Nikon Coolpix 5000 is an affordable option. While the sensor is only 2/3rd inch you can zoom and a Coolpix photo relay lens will directly fit a C-mount or into a 30mm eyetube. Other photo relay lenses will fit a standard microscope tube. It's a better sensor than most USB microscope cameras (AmScope etc.) up to the $300 to $400 range. You can have remote release, picture transfer to a laptop, and laptop viewing in addition the the articulating display and image magnification (for focusing) built into the camera.

[Dubious]

Thanks, I'll check out those options, which look interesting.

I have since found two cheaper USB cameras w 1" sensors on AliExpress:

E3 20MP 1 Inch SONY IMX183 CMOS sensor USB 3.0 USB3.0 digital Eyepiece video Industrial Industry biological microscope Camera
US $303.60 [Edit: the price on this is now given as $459]
https://www.aliexpress.com/item/4001150 ... WPO2G&mp=1

9MP USB3.0 40FPS Low noise Mircoscope C-mount eyepiece color camera E3ISPM09000KPB with Sony IMX533 1inch CMOS with Imageview
US $417.05
https://www.aliexpress.com/item/1005001 ... WPO2G&mp=1

Wish I could find some reliable reviews by people who have actually used them.

[Dubious]

I got sidetracked into seeing what I could accomplish with my existing Canon EOS 550D camera on the IMT-2. The options include: 1) attach it directly with an OM/EF adapter ring to the IMT2's front camera port; 2) attach it to the side video port using the Olympus MTV-3 with C-mount reducer lens; and 3) attach it to the side port without the MTV-3. Both of the side port options use the Olympus NFK 2.5x photo eyepiece inserted into the port as a relay. I tried all three options observing a slide reticule that with the 20x objective just filled the FOV (10x eyepieces), and found that #3 produced the best results.

#1 Front camera port. This is the easiest, and would be the best if I had a full-frame camera. No distortion and good contrast. But with the 550D's apc-s sensor, the camera sees only the center of the FOV--doable but not ideal:


#2. Side port using the MTV-3 with .3x reducer lens. Some vignetting by the C-mount opening, I think; noticeable barrel distortion 2/3 out, where contrast also begins to suffer. Could crop and use center portion but would not give me much more of FOV than camera gets from the front port.


#3. Side port without reducer lens, camera closer to port--ad hoc connection using clamp part of MTV, helicoid, macro ring and a bungee cord. Slight pincushioning approaching edges, but overall good result. In actual use, I would move the camera out a bit further so that it sees only a rectangular field.


So I'll probably go with #3 for now. I've ordered the part that should allow secure attachment of the camera. While I can adjust somewhat by not inserting the photo eyepiece all the way and by varying the length of the camera tube, the camera probably still won't be quite parfocal with the eyepieces; but I use the computer screen to focus photos anyway, so not that important.

[Hobbyst46]

#3 seems better than #1, as it provides a larger fraction of the FOV without noticeable chromatic and spherical aberrations.

[patta]

Nice, the #3 option looks good. I think it is called "eyepiece projection".

The same sidetracking happened to me in the other thread; to test afocal with the M12 lens, I had to test with APS-C too, and finally found a way to mount the camera properly (haven't done before!).

A bit late, option 4): use the Canon with a lens, in afocal over the side port, in front of the 2.5x eyepiece
The canon will need a prime lens, I think a compact 135 or 150mm would do, there are many old ones with M42 mount. Or an old Tessar. 50mm will be too wide for the 2.5x.

Question to answer, how was the Olympus 2.5x originally intended to be used? With eyepiece projection over 35mm film? Or in afocal, with a further lens?
Likely, with its intended setup, should had no distortion and correct parfocality.

[Scarodactyl]

The nfk eyepieces are projective. I tried doing afocal over a nikon 2.5x projectivd eyepiece with a 40mm lens just to try it and could not get the image in focus.
Option 3 does seem solid. There is some CA creeping im but outside the window of the image covered in option 1.

[Dubious]

Patta, in answer to your question, from what little I know, the NFK photo eyepieces were generally used focally but sometimes with a reducing lens. There were several--1.67x, 2.5x, 3.3x and 5x--used in a variety of configurations to connect cameras to the BH-2/IMT era Olympus microscopes. The 1.67x was used with video cameras, the 2.5x with 35mm cameras and some video cameras, the 3.3x with medium-format cameras, and the 5x for Polaroid and large format cameras. AlanWood.net has some useful information on the configuration of options available:
http://www.alanwood.net/olympus/digital ... scope.html

Here's the Polaroid camera back complete with shutter that Olympus sold for this system (I think). It would clamp directly onto the microscope's 38mm dovetail port, into which you would first insert the 5x NFK.
https://www.ebay.com/itm/324641653844
For connecting a 35mm full-frame camera, you would use the Photomicro Adapter-L with 2.5x NFK eyepiece in the port, and there was no additional lens.
http://www.alanwood.net/olympus/photomi ... ter-l.html

The MTV-3 adapter I used for #2 was used for video cameras and has a C-mount .3x reducing lens clamped inside. (The ones sold on Ebay are often missing the C-mount reducing lens.)
http://www.alanwood.net/olympus/c-mount ... scope.html