DIY webcam proof of concept

[chicagorandy]

Real AP astronomers..please look away lest your sensibilities be offended. lol

My ultimate goal is to be able to share the view from my Nexstar on my laptop with friends out on the patio of an evening. Prior to spending any $$ on an actual telescope intended budget video camera, I figured a 'no-cost' proof of concept DIY project was in order.

A few YouTube vids showed how it was done so why re-invent the wheel says I.

Parts - there are just 2 needed - the YT vids show using a film canister, but who the heck has those anymore? I used a pill bottle (at my age you end up with plenty of them - lol) and then an old USB 2.0 very cheap Kodak webcam that for years now has been in a cupboard gathering non-valuable antiquity.

Assembly - A Dremel with a cutoff disc (a hobby or hack saw will work well too) quickly removed the top & bottom of the pill bottle. Some sandpaper cleaned and smoothed the cut edges. Next a craft hot-melt glue gun affixed the cylinder to the face of the webcam after I removed and discarded the camera's plastic base. A Sharpie marker darkened the inside and outside of the cylinder to complete the DIY project.

3 fuzzy pics tell the whole story. I will report back once I get the opportunity to try it out. My telescope lives in a 'foster home'. lol

[Lokifish]

So that's where my pico guider disappeared to.

[mcolbert]

waiting with interest!

[chicagorandy]

The scope and I will re-unite next Saturday and I'll test the camera then. Didn't make it out to its foster home as expected this weekend. If the light pollution and sight lines weren't so lousy here at my house I wouldn't have these darn delays.

[Tillibobs]

That's how I began. Next stop, down the rabbit hole ! lol

[Gfamily]

You appear to still have the webcam lens in place, but seem to be using it without an eyepiece.

I'm not sure the optics will work like that.

What I suggest is that you try it at home, in the daytime, on a well lit target, so that you can confirm that getting an in-focus image is possible.

I'd rather you found out now, while you still have the time and the tools to fettle, rather than only finding out at the remote (r) location.

ETA: re-reading, it sounds as though your scope is not with you, in which case you may not be able to try it out beforehand.
But I'd still recommend trying it in daytime as soon as you get the chance.
If you can't, then at least try it out on the crescent moon first (in my experience, centering on a target is much more fiddly with a webcam as the field of view can be very small)

[chicagorandy]

Hi Gfamily- the webcam itself does of course have a small lens in place that can be focused, which I've done. My "remote site" is 25 miles away, namely my son's lovely backyard patio at his home in the northern suburbs of Chicago. Not exactly a dark site - lol - but much darker than my inner-city yard plus the food and drinks are fantastic and the indoor plumbing is a treat.

Testing the cheapie webcam is my first priority after settling in up there this Saturday evening.

[Lokifish]

A couple things to help make things go faster

Lens in = afocal through the eyepiece but can't be used without an eyepiece
Lens out = prime focus (the telescope acts as your lens) and can be used with an eyepiece for eyepiece projection.

Both have their advantages and disadvantages
Afocal will allow you to set focus with your eye then pop the camera in place an still keep focus. This requires "tuning" the focus on the webcam and making sure it's distance from the eyepiece doesn't change. Afocal also allows you to change the field of view a little bit by simply changing the eyepiece. The drawbacks are flaws in the eyepiece are seen in the image, darker image, and vignetting.

Prime focus allow for the greatest amount of light to reach the camera and without eyepiece aberration and vignetting. The trade off is FOV is fixed, and you need to focus using the camera only. The fixed FOV can be an advantage as you are using a very small part of the FOV with small sensors. So "close up" views of the moon are pretty easy with webcams. Plus if used with an eyepiece for eyepice projection, on can achieve significant levels of magnification.

The drawback for webcams in general is the lack of long exposure times, usually limited to 1/2s max. Another is lack of sensitivity in most cases. There are some very sensitive webcams but is limited to specific models.

[Larry 1969]

I did that exact experiment a while back.
I opened the web cam and removed the lens though. (Pretty easy job).
Crazy thing was how zoomed in it was! It was like looking at the moon with my 6.7mm EP in my 1,200mm F4.7 10" dob.

[mcolbert]

I knew I was keeping the old webcam for something!

[Gfamily]

Crazy thing was how zoomed in it was! It was like looking at the moon with my 6.7mm EP in my 1,200mm F4.7 10" dob.

I think i read somewhere that the image is similar to that seen by an eyepiece equivalent to the size of the diagonal across the sensor.

[chicagorandy]

Proof of concept setback/fail. The skies did NOT cooperate at all yesterday but I did get the chance to assemble the simple cabling to the scope and fire up the laptop.

Failure came when the durn pill bottle tube I attached to the webcam refused to fit into the diagonal. Just a shade too large a diameter. But holding it in place I was able to see the image on my laptop of the OTA internals etc. so I know it can work. I will go back to the workshop and try again.....or just buy one of the lower cost cameras sold on Amazon ready-made to the task. Like the Svbony 105 or 205. Again NOT for any sort of real AP use, just to display the live EP view to guests over the laptop.

[mcolbert]

the frustrating thing for DIYers is that sometimes commercial interests have got there first and we don't have to crack our skulls against the wall in order for our 'great' ideas to work.

[chicagorandy]

Indeed, but even commercial interests can have a hard time competing with the cost of DIY projects made at NO cost - lol

FWIW an honest-to-by-gosh REAL telescope video camera within MY budget and realistic needs was just now ordered via the good folks at Amazon. Should be in hand by this Wednesday - report to follow.

[Larry 1969]

I think i read somewhere that the image is similar to that seen by an eyepiece equivalent to the size of the diagonal across the sensor.

That makes sense. It's an awfully small sensor.
I replaced the web cam with a Revolution R2 imager and the image was more zoomed out but I was still unable to frame the entire moon.
I recently picked up a Canon T3i and it captures everything nicely..... Focusing with a dob is another story though......

[gcisko]

The Revolution Imager is the way to go. But it is $299.

[chicagorandy]

I started a new thread titled 'laptop viewing' to chronicle the success or failure of my new Svbony SV205 camera and .5 focal reducer.