SPC900 vs. Xbox Live webcam vs. Lifecam Cinema

[JamesF]

"What webcam can I use if I can't get/afford an SPC900?" seems to be a common question here, but there doesn't seem to be much empirical evidence on which to base a comparison of the alternatives, so last night I went out with a view to testing out two other cheap-ish cameras against the SPC900.

it's not unreasonable to suggest that this is not exactly a fair test. I've put, errr, lots of hours into learning to image with the SPC900. I've had very little time with the other two and I don't propose to repeat my efforts. I hope this is useful nonetheless.

All the test images were created using a 127 Mak on an EQ3-2. In the back of the Mak was a GSO/Revelation 2.5x barlow and an extension tube made from a kit Skywatcher barlow with the lenses removed. That gives a focal ratio of somewhere in the region of f/35. I've done the best I can in terms of settings and capture for the images rather than used the same for all, with the exception of only using Registax v6 for stacking and only making one attempt with each dataset which means there are some stacking artefacts in some of the images. The Xbox and Lifecam cameras also have sensors that could do with a bit of a clean, but it's taken me ages to get my SPC900 sensor clear of filth and I didn't have time to do the others. I used SharpCap for the captures and generally stuck to three minute runs. Seeing was pretty good generally, but not quite milkywaytastic. Before feeding the data into Registax I cropped the capture files down using PIPP, and each single image below is the result of a different capture run.

First the Xbox camera. Dirt cheap, and I'd modded it by cutting down the lens cowl and fitting a nosepiece with an IR filter, picking all the LEDs off the circuit board and fitting a small fan to the back. I had some trouble getting the colour balance anywhere near something that looked good with this camera and it was astonishingly noisy. Despite the fact that it will allow higher frame rates, the fastest I could get it to run and produce a reasonable image was 15fps. The images also came out astonishingly purple. I'm not talking a delicate shade of violet here. I mean quite vibrant in-your-face purple. I have no idea why that should be, but it was quite clear from the histograms in Registax that blue and red were far stronger than the green. On the positive front this camera does have a gain control and I used it to keep the SharpCap histogram around the 80% mark. I captured 1800 frames in each run and stacked the best 50%, adjusting the histogram to give a bit more natural colour. Registax did struggle a bit with the RGB alignment and I ended up having to adjust that by hand. Here are the results:

You know what? They're noisy and showing signs of being over-processed, but for a £4 webcam I think that's pretty good. When I started out imaging I'd have been very happy to have turned out something like that. The banding is clear and it's possible to make out the festoons and turbulence around the NEB and if you can do that in the first few times you've been out imaging the planets with a webcam I think you've made a fair job of it.

And so to the Lifecam Cinema. I modded this one and housed it in a Skywatcher 25mm kit eyepiece barrel with an IR filter on the end. Whilst the camera supports larger images there was no need and I just used 640x480 to try to keep the frame rate up. As it happened I found higher frame rates just made for very poor image quality and I ended up dropping back to 20fps at the most. There's no separate gain control on this camera and the white balance, brightness and gamma seem to work in a way that isn't entirely clear to me. Whilst the Xbox camera was plain noisy, this one just seemed really hard to get a decent image out of on the screen and I spent ages fiddling with the controls before getting something I felt was acceptable. I seem to have more stacking artefacts in these than any of the others and the colour balance was difficult to get reasonable. The camera seems exceptionally sensitive in red and I had to wind the red channel down a bit to balance things out. Even now two of the images look far too yellow, but that's probably fixable given more time. Registax did hideously badly at getting the RGB align right and I had to do that manually. Here they are:

The processing artefacts are a bit of a distraction, but in terms of detail I think these aren't bad. They're a definite step up from the Xbox camera, but then the camera itself is perhaps five times as expensive.

And finally, the daddy of them all, the SPC900. Compared to the other two cameras this one is so easy to use, the colours are far more controlled and it's just far easier to work with. It's a doddle to modify and the upgrade from SPC880 to SPC900 is easy as long as you have access to a Windows XP box. It won't do more than 10fps at 640x480 without serious compression of the data, but actually the other two don't do a whole lot better anyhow. Registax still had trouble stacking some of my files and created artefacts in the final images though less intrusive than those from the Lifecam, but otherwise there were no real problems in creating these:

I think it's quite obvious that the SPC900 leaves the others in the dust. For the £5 I paid for the ones I have it's brilliant. For the £50 or thereabouts it seems to go for now it's still a pretty good imaging camera. The detail is sharper, the colours are cleaner, the low-light performance is just better and it's actually less work.

It is entirely possible that with other scopes these camera may perform differently. I think the more light you can get on the Xbox and Lifecam cameras the better they do. I really wouldn't want to guess at how they'd perform in, say, a 200P, but hopefully this is a useful datapoint. The Xbox camera particularly seems to struggle a bit in low light, but it clearly still can work.

I know there are plenty of people with Xbox cameras or similar and a few with Lifecams, so come on, time to get capturing and post some images of your own. I'd be more than pleased to see people doing better than I have.

James

[Steve Ward]

Nice one James ,

It's good to actually see a comparison rather than just read an opinion for a change . . .

I'm glad I've got a couple of SPC's kicking about and not having to try and find an alternative.

Steve.

[bus_ter]

Thanks for posting that James. It's excellent to see comparisons made with the same equipment, on the same night. It's the only way you can know what works best, and by how much.

Interestingly your SPC900 images look almost identical to mine from last night (apart from the rotation) (). I wish you had your C9.25" setup so I could see what you're producing. I should be able to produce better images than a 5". Yours are some of the best images I've seen on a scope of that size. You need to wait until the Mrs has gone out and get that C9.25 badboy setup!

[bus_ter]

Regarding camera comparisons.. there must be someone who as upgraded from an SPC900 to a dedicated imager? Has anyone done a test like this between them? I'm tempted to upgrade my webcam, but I have a feeling the improvement will be very small for the amount of money spent. I've seen some amazing SPC900 images, and some quite poor DBK and Atik images. Obviously you can't compare unless they're taken at the same time, with the same equipment, and same processing, as James has demonstrated here to good effect.

[JamesF]

Interestingly your SPC900 images look almost identical to mine from last night (apart from the rotation) (http://stargazerslou...-new-sharpness/). I wish you had your C9.25" setup so I could see what you're producing. I should be able to produce better images than a 5". Yours are some of the best images I've seen on a scope of that size. You need to wait until the Mrs has gone out and get that C9.25 badboy setup!

Thank you. I'm very much looking forward to getting to use it again, too. It will have to happen soon...

James

[JamesF]

Regarding camera comparisons.. there must be someone who as upgraded from an SPC900 to a dedicated imager? Has anyone done a test like this between them? I'm tempted to upgrade my webcam, but I have a feeling the improvement will be very small for the amount of money spent. I've seen some amazing SPC900 images, and some quite poor DBK and Atik images. Obviously you can't compare unless they're taken at the same time, with the same equipment, and same processing, as James has demonstrated here to good effect.

I recall someone posting a few months or more back having upgraded from an SPC900 to a DFK21 with the same sensor in. The poster wasn't seeing a huge amount of difference between the two to the best of my recollection, but again you really need to do a back-to-back test, perhaps on several nights, to be sure. It's a dirty job, but someone's got to do it, so if anyone wants to give me a DFK21AU618 to test against I promise I'll give it my best shot

James

[cgarry]

Regarding camera comparisons.. there must be someone who as upgraded from an SPC900 to a dedicated imager? Has anyone done a test like this between them? I'm tempted to upgrade my webcam, but I have a feeling the improvement will be very small for the amount of money spent. I've seen some amazing SPC900 images, and some quite poor DBK and Atik images. Obviously you can't compare unless they're taken at the same time, with the same equipment, and same processing, as James has demonstrated here to good effect.

I could be wrong (and often am) but I think Stuart (Space Cowboy) did exactly that comparison. I do not have link to the thread though.

Cheers,

Chris

[JamesF]

I could be wrong (and often am) but I think Stuart (Space Cowboy) did exactly that comparison. I do not have link to the thread though.

Oh, yes, that does ring a bell.

James

[bus_ter]

I dug around and found this, is this the Space Cowboy post you're referring to?

unfortunately the pictures aren't working for me?

[JamesF]

Well done on finding the thread. The pictures possibly aren't working because a few got broken when the admins migrated the site to the new software. Could be worth PMing Stuart to see if he still has them and can repost?

James

[Delboy_Hog]

Excellent comparison James, great work, and some mighty fine images at the end of it, especially with "the daddy"!

I think experienced and newbie imagers alike can benefit from these kind of comparisons, and I often wonder how various bits of kit compare. There's so much kit out there, we're fortunate to have somewhere like SGL to seek people's opinions on 'which is better', but to see it so clearly is even more beneficial.

There's definitely room to expand on this theme - I can see a whole new forum on SGL opening up! Scopes, cameras, barlows, sub/capture lengths... so many things to compare!

Good job we get lots of clear nights to get out and conduct all these experiments isn't it? Oh wait, no...

[JamesF]

Good job we get lots of clear nights to get out and conduct all these experiments isn't it? Oh wait, no...

That's the most frustrating thing, to be honest. I've had the other two cameras sitting around for months since I modded them and chances for a decent test have been almost non-existent. I'd be happy to do more comparisons along these days as I'm sure would other people if the weather would just play ball a bit more often.

James

[bus_ter]

That's the most frustrating thing, to be honest. I've had the other two cameras sitting around for months since I modded them and chances for a decent test have been almost non-existent. I'd be happy to do more comparisons along these days as I'm sure would other people if the weather would just play ball a bit more often.

James

I would love to see a comparison from several of your scopes setup in the same conditions. Obviously it's asking a lot to setup multiple scopes!

[JamesF]

I would love to see a comparison from several of your scopes setup in the same conditions. Obviously it's asking a lot to setup multiple scopes!

That would be interesting to do once I have the obsy up and running.

James

[russellhq]

Any chance of adding the playstation eye to your comparisons:

http://www.ebay.co.u...c-/200842543068

I think the high frame rates might be of benefit for planetary work (60fps at 640x480 uncompressed)

I've got one but not had the chance to fully test it since getting a DSLR. I now use it as a guide cam as the drivers let you select up to 10s exposures (I use 2s in PHD).

[WaveSoarer]

It does appear that the SPC900 is the better webcam for planetary images. It does have the significant problem, though, that it's very difficult to get a hold of one. Are they even being manufactured anymore? They only appear to be avilable on eBay (or occasionally on here) but they are quite expensive and get snapped up quickly. Is there any other webcam that's equally as good (if not potentially better) and is currently being manufactured so that it's more readily available?

[bus_ter]

It does appear that the SPC900 is the better webcam for planetary images. It does have the significant problem, though, that it's very difficult to get a hold of one. Are they even being manufactured anymore? They only appear to be avilable on eBay (or occasionally on here) but they are quite expensive and get snapped up quickly. Is there any other webcam that's equally as good (if not potentially better) and is currently being manufactured so that it's more readily available?

They haven't been manufactured for a long time. (who would buy a 640x480 USB 1.0 webcam!). The best time to buy them was a couple of years ago when online shops had them as old stock and were selling them as cheap as £5 to get rid of them. I think a few savvy buyers bulk bought them and were slowly selling them off on Ebay at £50 a go. Nice profit!

[JamesF]

Any chance of adding the playstation eye to your comparisons:

http://www.ebay.co.u...c-/200842543068

I think the high frame rates might be of benefit for planetary work (60fps at 640x480 uncompressed)

That looks quite interesting. It appears to be significantly better than the Eye Toy though whilst I've found that it uses the OV7725 sensor chip it isn't at all clear what the actual sensitivity is from the datasheets I've found for it. What controls are available SharpCap when you select it as a camera?

James

[JamesF]

It does appear that the SPC900 is the better webcam for planetary images. It does have the significant problem, though, that it's very difficult to get a hold of one. Are they even being manufactured anymore? They only appear to be avilable on eBay (or occasionally on here) but they are quite expensive and get snapped up quickly. Is there any other webcam that's equally as good (if not potentially better) and is currently being manufactured so that it's more readily available?

The cheapest alternative I can find would be the one at the bottom of this page:

http://www.modernastronomy.co.uk/camerasPlanetary.html

James

[JamesF]

They haven't been manufactured for a long time. (who would buy a 640x480 USB 1.0 webcam!). The best time to buy them was a couple of years ago when online shops had them as old stock and were selling them as cheap as £5 to get rid of them. I think a few savvy buyers bulk bought them and were slowly selling them off on Ebay at £50 a go. Nice profit!

Quite a number of people bought several (including me) when they were £5, but I'm not aware of anyone who bought them at that price with the intention of selling them off at a premium once the supply ran out. I think a few people found limited supplies at low prices after the prices had gone up and then started selling them off on ebay, or took the opportunity to sell off the ones they'd already bought once they realised they could make a good profit on them.

James

[WaveSoarer]

James,

Thanks for the heads up. That does look very interesting indeed. Also, thanks for taking the time to do these comparisons. It's interesting that there is still no better altenative to the SPC900 in this price range. I have the xbox camera and it's been an interesting experience using it. I have recent images of Jupiter that are fairly similar to yours in the level of detail but I did play with the settings to overexpose so that I could get an image of Ganymede. I then adjusted the settings again to get a better view of Jupiter itself and then both were combined in photoshop (cropping etc) to produce a composite image. There is still nowhere near the level of detail you can get with the SPC900 of Jupiter though.

best wishes and thanks

Dave

[russellhq]

That looks quite interesting. It appears to be significantly better than the Eye Toy though whilst I've found that it uses the OV7725 sensor chip it isn't at all clear what the actual sensitivity is from the datasheets I've found for it. What controls are available SharpCap when you select it as a camera?

James

You can select frame rate, gain, exposure and RGB levels. All you need really. For more info on the exposure setting, I suggest reading the following:

http://codelaborator.../viewthread/60/

[Andymarrison]

So does anyone have a view of what's the best planetary imaging webcam that's not the SPC900 (since they are now like hen's teeth, and probably more expensive!) and is readily available right now for £50 or less?

[JamesF]

For mono imaging then the Point Grey Firefly cameras that Piotr(?) mentions on ebay may be a reasonable bet, though I don't know how much they'll have cost by the time delivery is added.

For colour I'm really not sure at the moment. If I can try the Playstation Eye camera linked earlier in the thread (not the Eye Toy) we'll see how that does. Some of the information about it suggests that it has good low light sensitivity and combined with the low resolution and USB2 interface it might work well. The Lifecams might work ok in your CPC800, but by the time you've modded it, found a barrel to fit and added an IR filter you might not come in under £50 either unless you have bits already lying about that you can scavenge.

James

[Andymarrison]

Thanks James - I might give the Lifecam route a go - it'll be fun fiddling about with the various bits anyway!