which sony IMX sensor to use for microscope

[micromicro]

Hi folks,

i'm planning to buy a trinocular microscope for soldering and inspecting. I'm unsure which sensor to choose for the microscope.
The IMX290 was choosen in former times,but might be outdated? The IMX334 is often seen on cheaper china-cams for microscope-use.
Or would you recommend IMX485 or IMX585 or else?
Would be great to hear what the pros here come up with.

thx in advance!

[jfiresto]

Is this for taking videos? Streaming live video? Taking snapshots?

And for which microscope?

[micromicro]

Hi John,
thx for your reply.
I do not make videos, no live streaming, just need crisp view for taking pictures.
Will inspect platines for defects and will maybe need to solder just by viewing to the monitor (and not through the oculares).

https://amscope.de/products/amscope-7-45x-trinocular-zoom-stereo-microscope-head-simul-focal-widefield-black
is the microscope i use.

[KaneTW]

You can use a 1x adapter and a 2/3"-1" sensor or 0.5x adapter and a 1/2" sensor.

The resolution of the microscope is rather poor and you do not require global shutter. As long as the sensor is physically large enough to fill out the image, anything will work.

[micromicro]

@KaneTW

thx  for your input. i forgot to mention, that a c-Mount is used.
There is the 8.3MP sony imx 334 with an optical format of 1/1.8  at a pixel size of 2 x 2 µm. Means: to go with 0.7x Barlow ?
or
sony imx 485  8.3MP 1/1.2" Optical Form-factor and pixel size of 2.9 x 2.9 µm. Maybe use with Barlow 0.3x?

Compared these two in security cam :

advantages easy to see for the imx485, but would there be an advantage in microscope-application?

regards

[jfiresto]

Thanks for that info. Getting live video to view on a monitor is probably the greatest demand you would put on a camera, since the video frame rate severely limits the exposure time and demands a more sensitive sensor. How much more depends on the microscope, the magnification and the type of illumination. If you want to think in terms of f-stops, the Greenough microscope you are looking could easily lose an f-stop of brightness compared to some other designs, its "simulfocal" (50:50) beam splitters lose another, and a typical Amscope camera, another three compared to one using an IM585X if the datasheet is realistic.

More magnification will add to that. My old microscope only has a 6-31X magnification range, and it still loses a couple f-stops brightness zooming from minimum to maximum. This got the attention of its fastidious designers who added a circular slide rule that shows how much to multiply the exposure time – and not waste film:



As you can see, the light loss really is not so bad – over the first half of the magnification range. I am not sure I want to know how dark things would get if the microscope could zoom to 45X. You would not by any chance want to inspect BGAs? I remember a video from Louis Rossmann in which he wanted to demo that. He could not get enough light from a 150W halogen light source at full, a new bulb every 50 hours, brightness.

[micromicro]

@jfiresto
that's an interesting aspect, i did'nt focus in depth yet.
There are beamsplitters 70/30 , that will send 70% of the light to digital cam. The quality of images should be better.

BGA's? Not planned, but it should be capable to inspect these too with decent quality.

To avoid the downside of the amscope (50/50 split) i could use only the digital microscope, so no splitting.
Might get some time to get used to watch straight forward to monitor while hands working at a different place.
Side-effect: better working position with straight back... 

Even the small IMX334 sensor brings quite good results. Example:

[jfiresto]

Even the small IMX334 sensor brings quite good results....

Yes, a small sensor can be quite good – when it has enough light. The video's bright, early pictures, are at minimum zoom, with a ca. 21mm field of view. Typically, that would be around 10X magnification and at the left end of the exposure-time scale I showed earlier. Later, the video shows the microscope at maximum zoom and with not enough light:



This situation would be well off the right end of the above scale, and deep into "empty magnification". I am not sure what the video is trying to show, here, perhaps overblown specsmanship?

There are so many details about microscopes if you want to improve. Sometimes you just have to observe then experiment.

[micromicro]

@jfiresto

i think they want to point out (with that quick movements of the board) a good video-capability is given with the IMX334.
It's around 100US$ and i'll try this first. Thanks for your valuable input! 

[jfiresto]

You are welcome. For $100, I bet the camera, at the very least, will be quite helpful for discovering what you ultimately need in a camera and the microscope – without spending a lot of money. I am tempted to get a Raspberry PI HQ camera, to see what it can do, but already have several other things I should first try.