webcams and expriments..

[simonmc]

Well after a few years of not using my scopes, decided to get some use out of them. After alot of fun, earlier in the week when the nights were clear, i decided to get use them more. My main interest has always being imaging but managed to lose my spc900. Not yet wishing to attach my canon DSLR to the dob or 127mak i had a look around on the net for a suitable replacement. I ordered a nose piece and some cheap webcams to use. I got the 1.3m asda one, a ps3 eye, some generic ebay ones and an xbox livecam. I have modified the asda one and also the xbox one. The others have not yet turned up. Not including the nose piece i have spent less than £20 so far.

I will try and get a comparsion of them all when they are here and put it all in one place. Today though, I have been playing with the xbox one and overall seem impressed as many have noted. Mine does have a fair few dead pixels and it does generate a fair bit of heat. I placed it in a wooden box so no light could get in and started to mess with the settings in sharpcap. I found that if i set it to 640x480 and 5 fps with the exposure at 2 it would start to white out, but the exposures were around 5 seconds long. At 10fps and the exposure at max it would take 2 second exposures with a lot less whiting out. This would suggest that some cooling would be in order. So i have ordered a small tec cooler and a heatsink and fan for a graphics card that i hope will do the job. Im thinking of controlling the tec with some sort of PWM drive. My idea is to have this setup as a 'cooling module' that i can use on different webcams to evaluate the results. Im looking forward to these tests, it should be interesting to see what happens.

I have much less experiance with CMOS sensors than with CCD ones but whist looking around the net, I had a look at Steve Chambers site about his mods after a vague memory of modding a cmos camera years ago to one of his 'recipies'. I remember that ti worked but went on to ccd based webcams due to the better sensitivity. However with the improvment of sensors in the last few years it might be alot more relevant today. Maybe someone with a bit more software experiance than me (Im a Hardware Engineer), could look a bit deeper at this. Apart from a simple circuit, his mod seemed to be more based on changing the driver of the camera to put it into a more appropriate mode for astro needs.

Anyway off to find some more data off the 'net' and to stare really hard at the cameras i have as i dont think i will be able to do any real testing tonight. We have over 4" of snow here in Verwood.

Simon

[JamesF]

Sounds interesting. I modded a couple of xbox cams to fit a 30mm (I think) fan to the back, powered off the USB cable. It did seem to improve things a little.

I'd definitely recommend putting a DSLR on the back of the 127 Mak, btw. I use an EOS<->T2 converter to fit the camera straight to the visual back of the Mak and it's about perfect for full disc lunar and solar (with a filter on the front) imaging. The height of the image has to be close to 90% of the sensor, if not more, so it's possible to get plenty of detail.

James

[simonmc]

Oh i know. I do have one to fit the 500d but would like to get a half decent webcam up together. That way i can sort of progress to the DSLR when i get to the limits of the webcam. Im classing it as a learning experiance with the next step already here, not on an expensive wish list, if you see what i mean. Also with the cooling module i have in mind i can swap it to another webcam. Thinking about it i found a d-link dru-350 in a box in the office which can have the sc lx mods done to it. It has the same chipsets as the phillips but with a sharp ccd. Might have a look out for a sony chip to swap out at some point. Also better check it still works, esp as i now run win 7 and may have to find a driver.

Has anybody got the datasheet for the driver chip in the xbox cam?

Simon

[simonmc]

Ops ment to say its a microsoft chip x803500-005. Also a bit neardy i know but my daughter has a microscope with a electronic eyepiece so whilst the xbox cam was apart i had a quick look at the ccd chip to see if it had any markings. There was none, not even on the substrate. Only some photo registration marks. It did however look really cool under high magnification.

Simon

[Twiggles]

Ooh, this could be interesting to follow! I know many have gone the xbox cam route, but I also went out and got an asda one, mainly because I didn't want to wait for an xbox cam to be delivered and it was an excuse to hack something up!

I assume that it is this one: http://groceries.asda.com/asda-estore/catalog/sectionpagecontainer.jsp?skuId=910000508893&departmentid=1214921923802&aisleid=1215109789266&startValue=401

Have you tried to take it apart yet? If you need any pointers just let me know. From the few cloudless nights we've had I've not had much luck with it yet, there doesn't appear to be any way to change the settings in windows (I'm using W7 64) which only leaves you with sharpcap. When trying to view Jupiter its always over exposed but been advised to try reducing the aperture down so going to give that a shot if we ever see the stars again here. Daylight viewing has been ok, if a little grainy but I may have chosen something too close so perhaps not getting decent enough focus.

Good luck!

[simonmc]

Ooh, this could be interesting to follow! I know many have gone the xbox cam route, but I also went out and got an asda one, mainly because I didn't want to wait for an xbox cam to be delivered and it was an excuse to hack something up!

I assume that it is this one: http://groceries.asd...&startValue=401

Have you tried to take it apart yet? If you need any pointers just let me know. From the few cloudless nights we've had I've not had much luck with it yet, there doesn't appear to be any way to change the settings in windows (I'm using W7 64) which only leaves you with sharpcap. When trying to view Jupiter its always over exposed but been advised to try reducing the aperture down so going to give that a shot if we ever see the stars again here. Daylight viewing has been ok, if a little grainy but I may have chosen something too close so perhaps not getting decent enough focus.

Good luck!

Thats the one. Im also using the 64bit version of windows, but have only used sharpcap with it at the moment. I did seem to have reasonable control over the camera with it though, but not through a telescope. Had it apart a few times now, and it does come apart very easily once the front cover is removed. Managed to do it with out marking the plastic at all, which i was happy about. I have only been messing the last couple of days and the weather has not been co-operating at all! When i get the time i would llike to hunt out the driver and see if this can be modified at all. I know what you mean about having to wait for mail ordered stuff. I got a couple of bits on order at the moment and its annoying having to wait when you want to push on. I also managed to get a 0.5x focal reducer off the bay yesterday. Dindnt win the action but got a second chance offer straight away so took it!

Simon

[Stargazer33]

I also managed to get a 0.5x focal reducer off the bay yesterday. Dindnt win the action but got a second chance offer straight away so took it!

Simon

Sounds like the seller was trying to bump the price up but came a cropper when they actually won the auction themselves!

[simonmc]

Sounds like the seller was trying to bump the price up but came a cropper when they actually won the auction themselves!

Funny thats what i said to the wife.

I have been reading a load of threads on here, about cameras and cooling and as such also ordered a LED light dimmer. I call it research, but i belive my wife has another name for it, when im looking on ebay. Esp when odd things start turning up in the post.

Simon

[simonmc]

None of my ordered bits have arrived yet. Not really surprised on about the stuff i ordered from china but some of the uk stuff i hope to arrive tommorow. One interesting thing i read today was a comment on a youtube video that the cheaper focal reducers are just 25mm f4 achromats out of binoculars. This got me thinking.. I have some duplicate filters that i dont use. Measured the glass and they 28mm. So i ordered a set of these from ebay.

http://www.ebay.co.uk/itm/3-In-1-Eyeglass-Binoculars-3x28-Magnification-Observing-Telescope-Toy-/290723609945?pt=LH_DefaultDomain_3&hash=item43b07a3d59 .

Just hope they have glass lens in them, not that im expecting quality. If there plastic i will have to give them to my daughter. Anyhow if there at least half decent i will mount one of the lenses in a filter case and compair them to 'real' reducer i have on order. Might be interesting...

Simon

[mikehab]

I'm rather intrigued by this thread too .... it'll be interesting to see your findings. I've been playing around with a few old webcams too ... primarily a Microsoft VX-5000 (~£10 from Amazon) and also an XBox webcam. I've taken some images using the VX-5000 of Saturn & Jupiter through my Nexstar 4SE, using SharpCap and stacked in either Registax or AS2!...

https://lh6.googleusercontent.com/-Xw5ies4_jPA/T4yUyYQ4WnI/AAAAAAAAAFs/1rshcPK_5uQ/s226/Saturn_15_04_2012%252023_39_16.jpg

https://lh5.googleusercontent.com/-IJwkCz8nFGU/T8PgyFfd6nI/AAAAAAAAAJk/bTPQZwCAPkw/s270/Saturn_2012_05_27.png

https://lh6.googleusercontent.com/--GNjBGVMxYI/UEkW5nKae0I/AAAAAAAAAO4/MqYNEuvE8rA/s256/Jupiter1.jpg

https://lh5.googleusercontent.com/-kCLiIORAYKA/UON6ODR9EjI/AAAAAAAAAYA/Ttx4L1Nk57Y/s200/Jupiter-01-01-2013.jpg

Unfortunately I haven't had any clear skies to test the xbox webcam yet - but when I do I'll post them here for comparison.

Mike

[simonmc]

I dont think many people have had clear skys for a while. I certainly havn't since friday. I like your pics. Your first one reminded me of my first view of saturn.

I saw some pics on here somewhere iirc, of the orion nebular taken with a ps3 camera. They looked quite good. I have one of them on order as well and would like to do a comparison of the asda cam, the xbox cam and ps3 one. Do you have any idea of the sensors and driver chips in the microsoft VX-5000? It would be nice to have a sort of reference of sensor chips and drivers used in various webcams and their apparent usefulness in astrophotography.

A present from my daughter for xmas was on of those webcam man camera's. So after she went to bed i poped the camera out of the 'man' casing. It uses a tiny (~2.5mm x 3.5mm) cmos sensor and a ARK3399B driver chip. Added that bit more as a reminder to myself as i have to put it back together before she wakes up in the morning! However when we do get a clear night to test various cameras i will add that one in. It should look funny hanging out the focuser as it uses a standard 12mm lens.

Simon

[simonmc]

Well i tested webcam man with and without the ir filter and the results were not good. Even with the standard lens it did not seem as good as the asda cam.

On another aside the commercial focal reducer has just arrived along with the ps3 cam. The focal reducer has a 28mm doublet with approximatly 65mm focal length. The base of the doublet is 5mm back from the start of the filter threads. It will be nice to have a clear night and some time to do some testing!

Simon.

[simonmc]

Well in the last hour or so i have been messing with the PS3 eye webcam. It turns out mine is the later type with the OV538 controller and OV07720 where as the earlier one had a OV534 controller. I managed to break the square pcb mounted lens holder whilst trying to remove the lens from it. Shame but the lens is salvageable. I found another holder (came from webcam man) so i can swap the lens now with the selection of other ones i have. I used the CL-EYE driver from AlexP on the NUI group forum on windows 7. Using this driver the exposures can be set to 10 seconds with SharpCap. It seems very sensitive to UV and IR. It looks like thic webcam has great potential, as much if not more than the xbox cam.

I have also found that if i use 3 filters as spacers i can bring the 0.5x focal reducer into focus, basically using it as a 28mm objective. Just pointing it out the window i can clearly see across the road. I will get some pics on a bit of a comparison of a normal webcam lens (with IR filter removed) and using the focal reducer as an objective.

Simon

[JamesF]

I broke the lens mount on mine when I took it apart and had to replace it, too. I think the lens might actually be glued in.

James

[simonmc]

Mine was. I think though the lens will clean up in the lathe ok. Will give it a go next time im set up for 0.5mm threads. I really do like the wide/close setting it has.

Simon

[simonmc]

Hopefully some pics.

This is using a normal webcam lens with the IR removed. Single snapshot at 15fps

[simonmc]

This one is same lens at 1fps

[simonmc]

This one is with the focal reducer as a lens. Shot at 15fps. If you have difficulty seeing what it is its the tree trunk of the tree seen through the arch in the last pic with part of the green trellis behind it.

[simonmc]

And this is the same at 1fps.

These last ones i dont think i focused it spot on, but did not have much time as all the pics had to be taken trough the open kitchen door as it was raining. Obviously that made the kitchen very cold, and i was getting moaned at! Also i did not change any of the camera settings. Like i said a bit of a rush job.

Simon

[russellhq]

I also found the PS3 camera performed better than the xbox camera.

The setttings I use in sharpcap are RGB & exposure sliders all the way to the right and gain slider all the way to the left, then adjust FPS to suit the target. I use it now for guiding and it seems to perform well.

[simonmc]

I will try that thanks.

Simon

[simonmc]

Well skys looked clear for a bit so set up with xbox cam and the PS3 cam. Well i was a bit slow and the cloads rolled in. I did manage to get a couple of snap shots from both cams using the focal reducer as an objective. All the settings were automatic

This was the PS3 cam.

[simonmc]

This was the xbox cam.

I did try and get the picture through the same amount of cloud but as you can guess this was not very scientific!

However the xbox cam produced darker blacks and a less washed out image. There are several idea's that i will try on the next time its clear. I would like to add a baffle to the optical train as the setup at the moment does not have any, just the reducer, 3 filters with the glass removed as spacers and the webcam adapter. I did fit a blackened cardboard tube to the lens, to try and stop refections from effecting the image as the garden lights were on, and basically see if it helped any. It did a little bit. Also i have also only just ordered an IR filter.

One thing that also made me giggle a bit was i had trouble getting focus on the moon when there was no cloud. I just kept getting this washed out disk with a big halo. After messing with the settings the cloud came in and i was able to get focus. I forgot that one of the filters i used as a spacer was my moon filter and i had removed the glass.

As an aside i did manage to see jupiter through the ps3 cam, but did not get an image due to the cloud coming in.

I dont really know why im doing these experiments with the reducer, i suppose its because i like the idea of a 'tiny telescope' and getting the best image i can from it. Its was not what i started out to do, but the wait for a load of bits from china has me side tracked, and its fun. 'Tiny Telescope'. I like that, maybe we could have some sort of competition when there are more clear skys to see who can come up with the best image from a web cam and focal reducer and no other optics or telescope involved. A sort of reverse "apature fever".

Simon

[russellhq]

Well skys looked clear for a bit so set up with xbox cam and the PS3 cam. Well i was a bit slow and the cloads rolled in. I did manage to get a couple of snap shots from both cams using the focal reducer as an objective. All the settings were automatic

This was the PS3 cam.

Looks like the gain is a bit high in this one. I'd sugget setting gain at 0. If you can't get the desired image, then drop the frame rate by half and and try again.

[simonmc]

Looks like the gain is a bit high in this one. I'd sugget setting gain at 0. If you can't get the desired image, then drop the frame rate by half and and try again.

I think your right. I did have it on auto for everything as i spent a while trying to get focus. What I, (and probable every one else) would like is a few hours of clear sky to expriment.

Simon