A budget Moon webcam

[kinetic (Steve)]

Here is another recent addition to my range of astro webcams I have made
over the years.
I’d give it a tentative thumbs up so far as a budget moon camera going by my
rough result last night. Planetary verdict is still pending. I’m yet to try it on Jup,
Saturn or Mars.

This one is a Logitech C500 which advertises itself as a true 1.3 Mpixel sensor.
It is the less sensitive CMOS type sensor….webcam people will know they are
generally an inferior choice over more sensitive CCD sensor cams.
On special the other day for 40 bucks

I have modded and used webcams for more than ten years on scopes and was
always curious how well the ‘over 640*480’ sensor webcams would perform on
the moon at least.

To make a workable camera I started by pulling the bugger apart.
This sequence is shown in PICs 1 to 8
Note in PIC6 there are 3 connectors that can be permanently unplugged
with no detrimental effect on the camera.. You just won’t have audio, a snapshot
ability or privacy switch sensing.

The power LED will need to also either be de-soldered (not my first choice), blackened with a Texta (doesn’t work), or covered with a blob of Blu-Tak
to stop light leaking into the view of the scope/sensor.

Next I made a simple 2” adaptor housing for it out of aluminium tubing.
( this was from a piece of 2” Alu handrail…finished outside diameter was
50.10mm and needed some anodizing to bring it up to a snug fit in a 2”
drawtube. My budget black anodizing is Black Duct Tape

I also needed a lip inside the housing for the camera circuit board to rest against
a rear end cover.
These I machined from old VCR heads.The front one has a 1.25” filter thread cut
into it to take my Baader IR filter (essential for astro work as we have removed the webcam IR filter as part of the lens assembly- see pic 8)
That is about it…..except that I needed to use my homemade 2” extension tube (PIC 16) to reach focus on the ED80.

Pic attached was captured last night using the ED80 and Stark Labs Craterlet capture
program (thanks J for putting me on to that program)
ED80 was piggybacked on my main 12” OTA.
3x 30 sec AVIs were stacked in Registax V5 and a mosaic made.
I can’t believe how rusty I am in Registax. It has been years since I have used it
I was able to select many capture resolutions and ended up using 960x720p at 15 fps
(native res is stated as 1280x1024 but was very slow….about 1 fps)

Steve

[asimov (John)]

Nice work Steve. Yes the CMOS cams are fine for moon imaging.

[5ash (Philip)]

Nice to see some colours in a moon image , well done
Philip

[kinetic (Steve)]

Thanks Guys,

I think the colours might be a bit misleading. They don't quite
match up on different pieces of the mosaic for one thing
and on another night I get different hues
When I do a colour correction on the final mosaic to daylight 6500K
I get a warm overall brown change to a more 'realistic' grey I am
used to
Anyway, here is a result from this morning when my son decided to
join me in the dome at 3am.
You always miss a bit don't ya?

Edit: a saturation tweak on right.

Steve

[kinetic (Steve)]

A few more results.

Pic 1: Native 1280x1024 resolution. 4 AVIs joined top to bottom but
shutter/gain seemed to changed on the bottom 2 AVIs.
I auto-stitched them anyway to show resolution and image scale.

Pic 2: 960x720 res. This res seems to work well and the shutter/gain
didn't alter. Auto stitch didn't like joining 1 and 2 so I did them manually.
(3 AVIs top to bottom.)

Pic 3: 640x 480. Doesn't perform very well at this res.

Pic 4: A comparison of resolution between modes.

I think if I can nail what is causing the gain/shutter to drift between the
capture of multiple AVIs, the 1280x1024 native res is a winner.

Steve

[mswhin63 (Malcolm)]

Hi Steve,

Do you have control over the exposure control on this camera?

The auto exposure is the killer for most webcams. When the camera senses the black background more than the light foreground it increases the exposure to compensate.

If the webcam is set to 6400K then it is usually set on "auto" and varies based on exposure levels and various other factors. If you can manually set this to 3400K I found is great for moon shots.

Your resolution though is improving.

[kinetic (Steve)]

yep Malcolm I have a bit of control.
I can leave it on Auto or uncheck and then have control over
Gain and Exposure etc
However, as I said, in 1280x1204 it seems to have a mind of it's own
once capture starts.
A webcam friend of mine, Jan, reports similar sounding behaviour with
a 1280x1204 Trust WB5400 webcam.

from his site:

But: after tweaking the camera controls you are in for another shock: when you start the AVI the camera controls go haywire and the driver jumps into some kind of 'AUTO' mode, resulting in heavily overexposed frames.
After about 10-15 seconds the camera more or less 'remembers' the settings you had selected and then all is rather OK again. But: the first 30 frames of your AVI cannot be used, alas. But even after reaching a more or less stable situation the camera still shows a will of its own ...
Because of this strange behaviour the camera cannot be used for mosaics, as the frames differ far too much for a seamless stitching.

This is exactly what this one does. But only in 1280x1204 native resolution.
It could be I have the FPS set too high, my USB2.0 bandwidth is being
compromised...dunno. I also get many dropped frames as Jan reports
as well.

One thing I haven't tried is Martin Burri's WcCtrl yet.
That could fix things.

Steve

[mswhin63 (Malcolm)]

OK sorry, came in late to the thread ad didn't notice it. OK the software has the exposure control maybe not the camera, this is why possibly you are experiencing control problems. The only software that I know that displays controllable control is SharpCap. If the camera cannot be control it won't display the features.

My webcam suppliers driver software cannot control the webcam but the Microsoft drivers can. I default Microsoft on mine. and have full control without any instability.

[scopemankit (Chris)]

Nice work and nice images of Clavius. So who need SOHO?