Cheap webcam with tiny FOV

[smolloy]

Hi all,

I found a webcam in a second-hand shop for less than 2 quid, and decided it would be a cheap experiment into imaging with my scope. I hacked it apart, removed the lens, and mounted it on the scope.

Since it's cloudy here tonight, I decided to play around with imaging a streetlight I can see about 1km away (maybe slightly less). I managed to get it into the FOV of the webcam, but noticed two problems.

The first was that it was difficult to get the light into focus, and I think this is related to trouble setting the exposure time and gain of the camera. Can someone advise me on the software they use for imaging? (Mac is preferable, but Windows is a possibility as well.)

The second is that the FOV seems incredibly small, with only the tiniest movements of the scope moving the streetlight entirely off the sensor.

I did a few quick calculations:

Width of the sensor = ~1/8th inch = 3.175 mm

Focal length of scope = 1200 mm

FOV = arctan( (3.175/2) / 1200) * 2 = 0.1516 degrees = 9.1 arcmins

Thus, it will take an object ~36 seconds to traverse the full FOV. Are these calculations right?

Is this hopelessly small? Is Jupiter a reasonable target for this? If not, how about the moon?

Thanks for any advice you can offer.

Steve

[RT65CB-SWL]

Just adding a few extras that may prompt a few more responses.

1. what is the sensor is it CMOS or CCD? - CCD is usually preferred

2. for less then £2.00 you have not lost a fortune.

3. checkout QCUIAG WEBSITE www.qcuiag.org.uk

[smolloy]

1. what is the sensor is it CMOS or CCD? - CCD is usually preferred

To be honest, I'm not sure. I've been searching for details of the camera, but I can't find any. It's a Logitech V-UAP41 -- I'm afraid that's all I know

2. for less then £2.00 you have not lost a fortune.

Indeed! A nice cheap experiment, with little lost (except a few hours of my time, and the price of a coffee) if it doesn't work out.

3. checkout QCUIAG WEBSITE www.qcuiag.org.uk

Thanks for the link!

Hopefully someone can advise on my questions. Thanks for reading this far!

[Spica]

Hi all,

I found a webcam in a second-hand shop for less than 2 quid, and decided it would be a cheap experiment into imaging with my scope. I hacked it apart, removed the lens, and mounted it on the scope.

Since it's cloudy here tonight, I decided to play around with imaging a streetlight I can see about 1km away (maybe slightly less). I managed to get it into the FOV of the webcam, but noticed two problems.

The first was that it was difficult to get the light into focus, and I think this is related to trouble setting the exposure time and gain of the camera. Can someone advise me on the software they use for imaging? (Mac is preferable, but Windows is a possibility as well.)

The second is that the FOV seems incredibly small, with only the tiniest movements of the scope moving the streetlight entirely off the sensor.

I did a few quick calculations:

Width of the sensor = ~1/8th inch = 3.175 mm

Focal length of scope = 1200 mm

FOV = arctan( (3.175/2) / 1200) * 2 = 0.1516 degrees = 9.1 arcmins

Thus, it will take an object ~36 seconds to traverse the full FOV. Are these calculations right?

Is this hopelessly small? Is Jupiter a reasonable target for this? If not, how about the moon?

Thanks for any advice you can offer.

Steve

Hi Steve. Can only pitch in on some of yr Q's: I am not an astro photographer myself, but I had one of those webcams for "normal" use a few years ago. I am not 100% sure but I sort of remember reading CMOS on the package, so this is my best bet on sensor type.

Here's a freeware for image processing DeepSkyStacker - Free

My uncle used it I remember, but how it works for lunar/planetary I couldn't say.

Hopefully someone will fill in on the calculations... they seem accurate at first glance.

Congrats on a great deal, then a freeware on top of that and you're a happy camper sleeping good at night! Great!