Webcam & Not able to Prime Focus

[M6RDP]

Hello, I am trying to get my Philips SPC900NC webcam to focus on my Celestron 400mm Travelscope but although I can focus on a nearby wall, I can't do so on a far off ship on the horizon. I turn the focus in to it's furthest point, but it needs to go further in. I gather this can be a problem on cheaper and especially shorter scopes. 

 

My question is: does anyone know a way I can attach the webcam (presumably with it's own lens back on) to the eyepiece?

The main reason I wanted to use a webcam in the first place was to stop having to do my stargazing through it, as it gives me eyestrain and makes me a little dizzy after a while at high magnifications. Looking at the terrestrial images yesterday on my laptop was a joy in comparison.

 

Thanks in advance. New to both astronomy and astrophotography as help appreciated!

 

Adam

Dawlish 

 

[happy-kat]

Hi

Are you running out of inward focus travel or outward? I'm surprised you are running out of inward focus travel.

When using the webcam you'll either need to keep the diagonal in or use an extension tube in order to reach infinity focus I think.

Have you removed the webcam's lens and are using the telescope like a giant lens?

Edited August 23, 2022 by happy-kat

[M6RDP]

Hello, I was just coming online to update my question. Thank you for answering and you are right, the problem was I had sharpcap set to 400% volume and I was getting an extremely pixelated image. 

And you are also right about the fact that I needed to use my diagonal. 

Huge learning curve for me so thank you for assisting. 

 

So now I have the image zoom back at 100% and it is crisp and focused. But it is miniscule! 

I'd need a magnifying glass to see the moon in there as it's more like a thumbnail! 

 

Is there anything I can do to increase the viewing window without pixelating the image? 

 

I'm using sharpcap by the way. 

 

Thanks. Adam 

 

[DaveL59]

the problem with the webcam is the small sensor on that one is only VGA (640x480 pixels) so any image would be small on a 1080P screen and will pixellate if you enlarge it. I found using the SPC900 on the moon in my LT70AZ which is f10 that you could only get a part of the moon in the view, since you are effectively cropping what the scope sees much like using a shorter FL eyepiece. Can't say what your scope would give as I don't have any short FL ones but give it a try and see how it shows. 

[AstroMuni]

1 hour ago, M6RDP said:

I turn the focus in to it's furthest point, but it needs to go further in.

I am assuming there is nothing between the camera and the focuser? i.e. Remove any diagonals etc. You could try using a barlow to increase the FL.

26 minutes ago, M6RDP said:

And you are also right about the fact that I needed to use my diagonal. 

EDIT: It looks like you meant that you need it to come further out, hence ignore what I said.

Edited August 23, 2022 by AstroMuni

[M6RDP]

Thanks Dave, I will not give up hope yet then until I have tried imaging the moon on the next clear night. The target I am trying this afternoon during daylight is is an island about 8 miles away and it is quite small, maybe 1/10 the length of the total view. 

 

I had read so many glowing reviews of the SPC 900 but now I am starting to ask myself why would you even use a webcam if the image is so small on a laptop. 

 

Anyway I will report back when I next see the moon, which looks like it may be towards the end of the week when the high-pressure sets in again. 

 

Cheers for now. Adam 

 

[DaveL59]

I've only messed about a little with mine and at the time was on an untracked mount so harder to keep things in view. The Logitech C270 is apparently pretty good and supported in sharpcap too and gives a 720P image size but isn't a CCD sensor like the old SPC tho still quite sensitive. Is yours mod'd for long exposure, the one I have is a standard one.

[M6RDP]

Dave, no not my knowledge. I was hoping to use it for imaging in place of my smartphone which is so fiddly. But at least I I was able to capture some beautiful videos of Saturn and the moon that way. The ZWO ASI120MC-S might have been a better choice but I really didn't want to spend that kind of money on what is a new hobby for me. 

Two days of rather futile fiddling around with it has  rather dampened my enthusiasm but I will try and capture a lunar image and post my results, so the idea was to use it for planetary imaging (and also wildlife photography). But with so small a capture screen it is a non-starter really! 

Thanks again. Actually the C270 was very nearly my choice, but who knows the ZWO might end up on my Christmas list after all! 

 

[DaveL59]

Remember to have fun trying 🙂

For the moon you may have to try a mosaic depending on the FoV with your scope or even most of the more affordable astro cameras as they are small sensor too. Been meaning to hook the APS-C DSLR up and shoot the moon but so far haven't got around to it. Have to find the T2 adaptor first lol.

Saturn and Jupiter should be doable tho with the SPC, it used to be a very popular camera with several folks here using them from what I've read. Most have moved on to the more expensive gear now tho.

PS - I was tempted to use my C270 for this as well but with covid and the crazy price hikes plus needing to video conference for work that one stayed tethered to the PC.

Edited August 23, 2022 by DaveL59

[M6RDP]

Thanks Dave, it's enthusiasm from folks like you that keep beginners like me interested. I was tempted to give up with amateur radio not being able to put up technical equipment, but have had years of fun with just simple wire aerials and low power, so thank you for the  (much needed!) morale boost. Without other people it's easy to lose interest. I'll be back......! 

[DaveL59]

6 minutes ago, M6RDP said:

Thanks Dave, it's enthusiasm from folks like you that keep beginners like me interested. I was tempted to give up with amateur radio not being able to put up technical equipment, but have had years of fun with just simple wire aerials and low power, so thank you for the  (much needed!) morale boost. Without other people it's easy to lose interest. I'll be back......! 

There's many here way more qualified than me on the imaging side, I'm pretty much visual but have a slight interest hence having the SPC myself. Might one day play with EEVA rather than imaging so having something to experiment with seemed worthwhile. Know what you mean tho, always nice to get encouragement esp when hitting a wall 🙂 

[AstroMuni]

15 hours ago, M6RDP said:

I was hoping to use it for imaging in place of my smartphone which is so fiddly.

Have you tried the smartphone with an adapter? Here is what I managed to get sometime back with an iphone 8 attached to my Astromaster 130, so dont give up hope 🙂 Good luck!

Edited August 24, 2022 by AstroMuni

[M6RDP]

Hi Astromuni, 

 

Wow, that's a great shot. No nasty "green edges" too! Yes my first attempts at astrophotography have been with a smartphone and I will certainly be going back to that method after my disappointing results with the webcam. I've always fancied the idea of imaging on a larger screen because of eye strain issues, but I think a higher resolution ZWO camera would be a better choice. 

 

I even managed a short video of Saturn last month using my Huawei. After stacking the image was pretty good. Even before stacking the video showed the rings. And this is with a child telescope really, the Celestron Travelscope 70. 

I think my expectations of the webcam were too high. 

 

[AstroMuni]

1 hour ago, M6RDP said:

I even managed a short video of Saturn last month using my Huawei. After stacking the image was pretty good. Even before stacking the video showed the rings. And this is with a child telescope really, the Celestron Travelscope 70. 

Thats a good shot actually. If you use a lower zoom you should get better images. Beginner scopes like yours (and mine) are not geared for taking close ups of the planets. My best phone images came out when using a 25mm eyepiece. Another tip is to set a delay of atleast 2 secs, so that scope and camera get a chance to stabilise from vibrations after you have pressed the image capture button.

[Cosmic Geoff]

With a given telescope and camera, the width of the field is fixed unless you use a Barlow lens to zoom in, or crop the field digitally.  With a 400mm fl scope and the SPC900NC (without its lens) the field ought to be moon-sized.  The focal length will be too short, and the telescope too small, to get a good image of a planet, though you should be able to distinguish Saturn's rings. You should also read up on the process of 'lucky imaging' and taking & processing a video.

I suggest you try imaging some star clusters, galaxies and nebulae and see what you get.  For planets you really need a bigger scope with a longer focal length (££££), and a modern planetary camera (at minimum an ASI120MC-S, and preferably an ASI462MC) -£££ - would help.

[M6RDP]

Dave, Astromuni et al... 

Having checked YouTube videos of people using the same webcam with a nice useful image capture screen I decided it might have something to do with the software. So I switched from sharpcap to a really nice simple program called wxAstroCapture and to my astonishment the image capture screen is huge and really useful now. Attached is a photo of the MOD ship Hurst Point about 12 miles out in poor seeing conditions, so this webcam and software combination will be extremely effective I think for astrophotography now. 

 

Really glad I persevered now as this will make astronomy and astrophotography much more enjoyable now. Thank you for helping. Looking forward to trying some night-time targets now! 

 

Adam