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 Post subject: Which Webcam?
PostPosted: Tue Jan 14, 2014 7:21 pm 
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Joined: Fri Feb 22, 2008 5:02 pm
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Location: SURREY
I really have two related questions:

1. I have stripped down a Logitech webcam I had lying around (don't know which model), removed the lens and attached a nose, in the hope I could make a start at webcam imaging. Unfortunately I am unable to get a picture: if you move the webcam around it registers changes in light i.e. there is a signal but no proper picture (I also have the original software). Am I missing something basic in converting + trying to use this for basic imaging?

2. In the event I can not get this running, what would be a good webcam to start imaging, say for a budget up to / around £100 and where could I get one? I have looked for Phillips SPC 880 / 900 NC, and the Lumenera LU 070M (OK this is >£100) which were recommended to me but can't find them anywhere. Or should I go for something a bit better from the start?

Thanks.


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 Post subject: Re: Which Webcam?
PostPosted: Tue Jan 14, 2014 8:50 pm 
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Joined: Fri Dec 03, 2004 9:58 pm
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Location: Wellingborough
Hi.

Sticking with the Logitech webcam for the moment, I'll first apologise for asking a couple of silly questions to establish more clearly what is happening:

- did the webcam work before you removed the lens - i.e. did you get pictures with the original lens?

- when you get the response to light but no images, are you doing the test without a lens or telescope attached? The webcam has to have some sort of optical system present to form an image on the chip - otherwise it's just "light or dark".

- have you tried the modified webcam in your telescope, trying to image a distant object - tree, chimney etc or maybe the Moon (nice and bright, easy to find) ?

In my opinion the Toucams are still unrivalled amongst the domestic-market webcams for astro use. Unfortunately they are rarer than hen's teeth now. Dedicated planetary cameras are now available at maybe twice the cost of an old Toucam , so that is the way most imagers are going these days. We can cover alteratives to the Toucam in more detail if you wish,

regards,

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Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Tue Jan 14, 2014 10:29 pm 
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Thanks for your thoughts Brian.

Answering your questions: yes the webcam did work fine before - it was just lying around at home free (so to speak) and I thought I'd try and get it working with the telescope (I am relatively new to astronomy - keen, but loads to learn!) and, yes I have tried it in the telescope (Skywatcher 150PL) with the same effect (I tried just what you suggest this afternoon with no result). Below, I hope is an example of the 'picture' - as the camera isn moved around the chip registers differences in light qunatity i.e. cut out the light and it goes black

[img]
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[/img]

I would very much appreciate any other webcam suggestions, but with the difficulties I've had with the Logitech I was really looking for something off-the-shelf that would produce good results and (importantly) is easily available - this seems to be the tricky part! I can see that one day I'll need (want) to fork out for a CCD based camera but for now I would like to to learn the basics of this type of astroimaging before taking the more expensive plunge.


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 Post subject: Re: Which Webcam?
PostPosted: Wed Jan 15, 2014 6:50 pm 
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Location: Wellingborough
Just a thought - is it possible to test again with the lens replaced?

One problem that re-occurs time and again with Newtonian reflectors and webcams/cameras at prime focus is that the focal plane of the telescope may not be accessible to the camera. For focus to be achieved, the imaging chip must be placed exactly in the focal plane. If the focal plane of the telescope is inside the focuser tube, it will be accessible to eyepieces but the camera won't be able to reach it at all. Some Skywatcher focusers have an extra ring which can be unscrewed to allow a camera to get closer to focus (reduces the length of the drawtube) - I wonder if yours has this?

Anyway, I'm thinking you first of all need to get some idea of where the focal plane of your telescope is. What I do is to get a piece of translucent (tracing) paper, point the 'scope at the Moon with no eyepiece present and move the tracing paper back and forwards (to and from) the focuser until I see a nice image of the Moon on the paper. I then know that marks the focal plane of the optics, so that is where I need to be able to place the imaging chip of the camera. It certainly helps to know where the focal plane of the optics is as a first step.

If the problem is indeed that the camera can't reach the focal plane, there are three things you could try:

- use a barlow lens with the camera , sometimes this will move the focal plane out of the focuser tube far enough to get the image onto the camera chip

- move the primary mirror up the tube to push the focal plane further out :shock:

- replace the focuser with a "low-profile" unit

Just a few thoughts that may help :)

I'll get back later with some thoughts on webcam alternatives,

regards,

_________________
Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Thu Jan 16, 2014 12:43 pm 
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Good idea, however, I will need to wait until (if) ever it stops raining + we have a clear night to do so - it will be interesting to see the result. I did last time try the additon of a x2 barlow which unfortunately made no difference.


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 Post subject: Re: Which Webcam?
PostPosted: Mon Jan 20, 2014 2:04 pm 
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Joined: Fri Feb 22, 2008 5:02 pm
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Location: SURREY
Brian, at last we had a good sky last night which allowed me to try your focus experiment. The result showed the focal point to be within the upper 2cm of the focus tube and should therefore be within the correct range for the webcam sensor.

Regrettably I must therefore conclude that this webcam is not going to work, for whatever reason.

Which leaves me looking for a replacement, ideas welcome for alternatives that are available; it is clear that the Phillips SNC900 is a rare beast - I bid on one on Ebay yesterday which eventually went for £103!


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 Post subject: Re: Which Webcam?
PostPosted: Mon Jan 20, 2014 8:54 pm 
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Location: Wellingborough
Sorry to hear that your camera has died. That's a real nuisance.

In theory anyway you can make use of most webcams for imaging the brightest objects - Moon, planets, double stars, Sun (with full aperture solar filter). Problem is that the sensors on modern webcams are not particularly sensitive (they are designed to be used where there is plenty of light after all) and design is moving towards more and more automation in hardware and software function - just what the astrophotographer doesn't want. We need good control of things like exposure, gain, gamma and video compression for instance. To be honest, I think the day of the astro-webcam has passed :( . Modern-day imagers have mostly turned to purpose-built cameras such as the Imaging Source, QHY, ZWO, FLI etc models costing typically £250-£350 each. For this you get industrial build, framerates of many tens/sec up to hundreds/sec, updated firmware and software and troubleshooting support.

However there are still one or two webcams available that have been modified for use at the telescope with some success. At the bottom is the Xbox Live camera, still available from Ebay for about £4.99. With lens removed it makes a cheap, reasonably sensitive, if noisy introduction to webcam imaging. Then there are the Microsoft LifeCam Cinema and LifeCam Studio webcams, (£40-£60 from Amazon)- more complex to modify, needing a replacement case (or an empty eyepiece tube) to rehouse them. I'm only aware of a few of these that have been reported in the Astro Forums, and the main comment that sticks in my mind about then is that they work well with larger aperture telescopes (12-14 inches) but lack the sensitivity required to work well with smaller instruments.

It really boils down to how much you want to spend :)

Regards,

_________________
Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Tue Jan 21, 2014 12:20 pm 
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Joined: Fri Feb 22, 2008 5:02 pm
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Location: SURREY
Once again thanks Brian. After my experience with the Logitech I am now inclined to find something that works out the box but not too expensive. Any thoughts on the Orion Colour Imager IV, which seems to fit the bill, for a not too expensive price:

http://www.telescopehouse.com/acatalog/ ... tml#a52175


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 Post subject: Re: Which Webcam?
PostPosted: Tue Jan 21, 2014 7:50 pm 
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Personally, I'd not go with the Starshoot IV. It uses a relatively old CMOS sensor with small pixels and (by more modern standards) low sensitivity to light.

Prompted by your posts, I've been doing a bit of digging around on the Forums, and it seems that the Toucam may not be as dead as made out to be :shock:

365 Astronomy are selling the "Scopium" camera which appears to be an improved (their description) version of the original Celestron Neximage colour camera. The Neximage was/is identical internally to the Toucam 840K series cameras and uses the same CCD chip. I have two original 840k's and they are good "one-shot colour" planetary webcams. The Scopium works "right out of the box" (their words) and is currently £89.40:

http://www.365astronomy.com/scopiumcam- ... -2525.html

I can't find many posted images from this camera though:
http://www.astrobin.com/gear/11567/scopium-cam/
http://aam.8mag.net/coppermine/displayimage.php?pid=291
http://aam.8mag.net/coppermine/displayimage.php?pid=291

and a thread on Cloudynights (it's "Omegon in the US):
http://www.cloudynights.com/ubbthreads/ ... in/4626401

It's worth Googling "scopium astro camera"

As an alternative, 365 Astronomy have the more modern, upmarket ASI034MC Colour camera for £119, which you might consider:
http://www.365astronomy.com/zwo-asi034m ... -3700.html

I won't repeat the specs here, but it has a true USB2.0 interface and a long exposure capability (60sec) - although likely to be noisy in that mode. It is CMOS but a more modern chip with improved quantum efficiency. Worth considering.

If you want one of the best planetary cameras available currently, have a look on the 365 Astronomy site for the ASI120MC or ASI120MM cameras :D

Regards,

_________________
Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Wed Jan 22, 2014 2:44 pm 
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Location: SURREY
Well you've done it again - I need to look a little closer but reckon one of the two webcams at 365astronomy are just what I am looking for, watch this space (no pun intended!) - many thanks Brian. Whilst I realise these types of webcams are mainly for planetary and lunar imaging, are DSO objects possible - perhaps the closer / brighter ones such as the Orion Nebula?


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 Post subject: Re: Which Webcam?
PostPosted: Wed Jan 22, 2014 7:57 pm 
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Location: Wellingborough
I think the Scopium is limited to short exposure times only (less than 1sec) but the ZWO cameras are listed with exposures up to 60sec and have been used for deepsky imaging work.

Have a look at images posted in the Gallery here by "smerral" , and others on the ZWO user group:
http://zwoug.org/viewforum.php?f=23

Whilst the ZWO cameras are a bit noisy when compared to much more expensive "dedicated" deepsky cameras they do work quite well :)

Regards

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Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Fri Jan 24, 2014 2:05 pm 
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Ordered the ZWO ASI034MM in the end, will let you know how I get on in a few weeks.


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 Post subject: Re: Which Webcam?
PostPosted: Fri Jan 24, 2014 8:38 pm 
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Location: Wellingborough
Looking forward to seeing the first images 8)

Regards,

_________________
Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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 Post subject: Re: Which Webcam?
PostPosted: Wed May 21, 2014 3:28 pm 
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Joined: Fri Feb 22, 2008 5:02 pm
Posts: 23
Location: SURREY
I originally posted this query earlier this year - other priorities then got in the way, plus I subsequently had lots of problems getting the things to work. I could not, at first, get the ZWO ASI 034MC to work and had to visit the vendor, who also struggled (turned out to be issues with USB connections and AmCap). Eventually using Firecapture we got it fired up, however, by now I decided I would eventually need something for guiding so upgraded to the ZWO ASI120MC.

Only very recently did I then get to try out the set-up with my Skywatcher 150PL and x2 Barlow, which resulted in more problems! At last I have managed to get some images last weekend of Mars & Saturn. Room for improvement but I'm pleased for now and even my 30-something kids were impressed :)

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These are straight from the webcam + Registax, nothing else (can't afford Photoshop for now) but will try some more tinkering later; I took some Darks too, does it help to use these with webcam imaging? It just amazes me (a) what the digital sensor sees and ( B) the impact of stacking, particularly the wavelet function! In the end I paid more attention to the mount & alignment and discovered the exposure function in FireCapture! Yes I know, how could I overlook it, bit like leaving the lens cap on I suppose, won't do that again. These are with x2 Barlow, which was still very tricky to get the planets within the sensor's view and focused. Thanks for everyone's help & patience, now for the next challenge!


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 Post subject: Re: Which Webcam?
PostPosted: Wed May 21, 2014 5:33 pm 
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That is a great start, Well Done.

Mars and Saturn are both quite challenging targets in their own way. Although Mars is bright, it's quite small, and although Saturn is quite large, it's relatively faint. Your Mars reminds me of my first efforts with the planet in 2003, - maybe just a bit heavy on the wavelets - I call it my "pizza" period :D

Firecapture is a powerful capture program and well worth learning in detail. It does seem overwhelming at first, and I'm quite glad of my 10 years apprenticeship with my Toucams and K3CCDTools which served me well when it came to the 120Mc and Firecapture :)

Regards,

_________________
Brian
52.3N 0.6W
Wellingborough UK.

254mm LX90 on Superwedge, WO ZS66SD, Helios 102mm f5 on EQ1, Hunter 11x80, Pentax 10x50
ASI120MC Toucam Pros 740k/840k/900nc mono, Pentax K110D
Ro-Ro roof shed


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