Frustration! I need some advice please.

[SniffTheGlove]

Hello,

Trying to use a modded firmware SPC880 webcam (nee SPC900) on my 10in F7 Dob using Sharpcap.

Now the moon is fantastic via the webcam but the problem I am getting and the frustration is getting worse when the hours tick by is that other than the moon I can not see anything else in the night sky. No planets or stars etc.

When focusing on the moon using prime focus, the webcam is roughly 38mm from the focuser and I get great views (dependant of on seeing), yet if I then swing round and point at Jupiter I see nothing from the webcam.

I have tried every combination of focusing/exposure/gain/backlight comp but Jupiter (or any star) will not show it's self and my frustration over the last few weeks is building up.

Webcam is running on XP with 10fps and a resolution of 640x320.

I have swapped out webcam for EP's to make sure that Jupiter is in FOV and that it will drift across the centre of the EP FOV, I start with a 20mm, then a 9.7mm and then a 4.8mm making sure that Jupiter will drift in the centre of the FOV each time then I place Jupiter at the edge of the FOV then I swap in the webcam and wait watching the screen but nothing happens, not even a slight brightness change as if Jupiter has just passed by but slightly outside the webcam FOV.

Last night I spent 5 very cold hours just trying to get Jupiter or even any stars on the screen but nothing.

Can the SPC880 actually pick up the light from a star or is the CCD not that sensitive but I have read that people use the SPC880 as a guider therefore it must be able to stars to guide.

Please help with advice.

[rwg]

Hi Sean,

yes, the camera can pick up the light of jupiter and even stars, but it's a trickier business than the moon because aiming and settings on the camera are much more critical. The webcam field of view is really small - I have trouble enough getting things to stay in the FOV with a tracking scope, let alone a manual dob.

Here's some ideas...

Start with Polaris - it doesn't move - get it dead center field of view with an eyepiece, then switch in the camera. Adjust the camera settings to long exposure, high brightness and gain and see what you get.

If you can't find an object put the scope out of focus - you might see it appear as the out-of-focus donut grows bigger - that will then tell you which way to move the scope. The Sharpcap 'image boost' and 'image boost more' preview filters are good for this as they really push up the brightness of faint stuff.

Once you have some settings that work for polaris sorted out (webcam settings), save them so you can go back to them easily. Tbey should work for other stars but will likely be too bright for jupiter (it would show as a big white blob). Anyway, at this point you should be set to try on moving targets away from the celestial pole.

Robin

[The Bat]

When I am imaging a planet, if I turn my tracking motor off at the end of the session, it takes about 1 second for the planet to disappear from view on screen.

Think you may struggle getting/keeping Jupiter on your chip, which is looking at a tiny piece of sky. You certainly need higher exposure settings than for the moon, but you should definitely see something if it does happen to cross the fov.

Rachel

[SniffTheGlove]

Thanks, I'll give Polaris a go but it will have to be in a few days as I need some help getting the Dob out of the Obsy and setting up in the garden from where I can see Polaris as from the Obsy north is not viewable and the ground is muddy around the Obsy.

Mind you the moon is great tonight on the webcam

[SniffTheGlove]

A little update a week on....

I have not been able to get the scope out as there has not been a clear night and thankfully not had to get the scope onto the muddy/wet lawn. (A good thing is that my slab man is finally coming around next Monday to lay an observing patio so it will then be easy to move/wheel the Dob from the obsy onto the patio outside the obsy.

A further update as the has been a bit of a clearing this early evening I thought I would have a go with the camera. The sky has been clear for 30mins now and I struggles as usual then finally as Sirius came above the horizon I turn the scope and found it in my 32EP, then stepped down to 20EP then 9.7EP and finally my TV4.8EP and then move Sirius just slightly out of FOV and quickly swapped the cam in and switched on the Histogram and had the setting all mid point and waited, slowly the histgram show some movement and then I slowly moved the focuser and then a donut appeared, so focused the best I could but could not resolve the star properaly but managed to mix the settings and keep nuding the scope until I had a black background and a reasonable image and then clicked save on the setting.

The see is not that good but at least I know I can see Sirius and have the settings saved for next time.

5 mins later I have cloud!!

Thanks for all the help and suggestions, now I can work on getting a better image by tweaking what I have saved.

[Bizibilder]

You are really going to struggle without any drive - I have trouble WITH a driven mount!!

[SniffTheGlove]

You are really going to struggle without any drive - I have trouble WITH a driven mount!!

Yes I will, it's OK with the moon nudging a few mins as Registax can work around these duff nudged frames. As for other celestial objects I am part way through a EQ Platform build when can be see in the DIY section. Once this is OK then webcam movie and registax will be great for my needs.