Usage of Microscope Camera with Sharpcap

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Barnsey123
Posts: 3
Joined: Tue Mar 31, 2020 11:45 am

Usage of Microscope Camera with Sharpcap

#1

Post by Barnsey123 »

Hi all, I'm new here (on the forum AND to astrophotography, just dipping toe in water) so please be gentle! ;)

First the gear then the question(S)...

Gear:

Mount: SW HEQ5/Pro Rowan Belt Mod
Scope: Altair 102ED F7 with Deluxe Altair 70mm Focus Extender
Camera: S3CMOS Series USB3.0 CMOS, 23.2mm Diam. ToupCam Eyepiece 5MP Camera (From GTVison - GXCAM3EY-5)

Camera Sensor: Aptina MT9P001(C)
Sensor Details (quick):
Size: 1/2.5-inch (4:3)
Pixel Size: 2.2x2.2 Microns
Active Pixels: 2592 H x 1944 V
Color Filter Array: RGB Bayer Pattern
ADC Resolution: 12-bit, On-chip
Responsivity: 1.4 V/lux-sec (550nm)
Exposure Time (0.12ms -> 4s normal, 500ms --> 8s LX mode)
Binning Modes : 1x1, 2x2
Spectra Range: 380-650nm (with IR-filter)

Sensor Details: (detailed) :
https://www.onsemi.cn/pub/Collateral/MT9P001-D.PDF (not sure if there is much difference between C and D but only thing I could find)


Question (s):
In Sharpcap the camera is recognized OK (as S3CMOS05000KPA) which is correct as it matches with what the microscope software (ToupView) sees. However, the colorspace recognized by both pieces of software is different: 'ToupView' sees 'RGB24' but SharpCap only sees 'YUY2'. I believe YUY2 to be 'lossier' than RGB24 but obvs with benefit of smaller files.

Q1: Would Sharpcap be using it's own drivers? How can I make SharpCap use RGB24? Is that even necessary?
Q2: In LX mode I can squeeze 8secs exposure ( 4secs normally). I'm in a semi-urban location with lots of LP to the north and countryside to the south) as I'm not in a dark sky location are shorter exposures 'better' and 8secs usable? I haven't tried this yet as only looking at planets/moon and only used the camera once so far. Looking towards imaging DSO at some point.
Q3: Pixel size: 2.2x2.2 microns - is this any good?
Q4: How long EXACTLY is a piece of string?

Any replies would be welcome (well, some of them I expect) ;)

Would appreciate your thoughts

regards
Neil.
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Re: Usage of Microscope Camera with Sharpcap

#2

Post by admin »

Hi,

SharpCap doesn't have direct support for this brand of cameras, and is not something that I'm planning to add in the near future. However you have already seen that SharpCap can talk to the camera using the direct show driver that is installed with the camera software. Unfortunately you already encountered some of the limitations of this driver such as only being able to access the YUV colour space, meaning some colour fidelity is lost.

If you go to the manufacturers website, I believe that they also have an Ascom driver available for their range of cameras which may give you better support in SharpCap (at least for longer exposures at slower frame rates) than the direct show driver. However it is also possible that the maximum exposure that you are seeing may be limited by the camera hardware (astronomy cameras often have to be specially configured in hardware to allow the much longer exposure times). An eight second exposure would typically be considered on the rather short side for trying to do deep sky imaging, but if it's the longest that you have available then you still be able to get decent images of some of the brighter objects.

The 2.2 µm pixels on this type of camera would usually be considered to be on the small side – having more, but smaller, pixels can limit the maximum brightness each pixel can record without saturating and also exacerbates the problem of capturing faint objects – the smaller the pixels, the same amount of light to get spread over more of them.

Hope this helps, Robin (no idea about the string, sorry)
Barnsey123
Posts: 3
Joined: Tue Mar 31, 2020 11:45 am

Re: Usage of Microscope Camera with Sharpcap

#3

Post by Barnsey123 »

Thanks for quick reply....I got soooo much to learn.

Much appreciated

Barnsey
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