SPC880NC SPC900NC Mods.

[Cath]

until I decided that at that time there was little point using Linux as an imaging platform.

I guess that's the reason for oaCapture ?

[CSM]

Hi James - have downloaded Sharpcap on both computers and they both default to 30fps I420.  Will be interesting to see what the results actually achieve.  As a programmer - retired - I don't envy anyone trying to marry up the superabundance of hardware with all the different operating systems and browsers.  It was a nightmare 15 years ago, but now...

[JamesF]

I guess that's the reason for oaCapture ?

Yes, partly

James

[Coastliner]

Thanks for the tip re watching the histogram for video brightness, last night was fairly successful (using Sharpcap), but the capture suffered a fair amount of noise as a result of having the gain a tad high. I'll go for a lower gain and a higher brightness next time.

Neil.

[CSM]

Hi James - been fiddling around with the Sharpcap settings in an attempt to 'save time' by getting them the same as I use with Wxastrocapture.  Scales are rather different and I can't see any equivalent to the Colour WB-R and WB-B settings.  And what about the Moon with no colour required?  Any ideas?

Thanks

Colin

[JamesF]

Personally I'd leave those controls at their default settings anyhow, but I can't recall how to change them in SharpCap I'm afraid.  It may be that those controls are in a separate window somewhere.  Hopefully someone who has used SharpCap rather more recently will be able to help.

James

[CSM]

Hi James - just found the controls - under Options and Video Capture Filter and Picture.  Thanks

[JamesF]

My memory isn't quite as bad as I thought

James

[CSM]

Hi James - it seems that even if the Philips SPC900NC/00 is USB 1.1 it will still do 30 fps ok if the settings are right.  I tried on Monday night but apart from the poor seeing - mainly haze - I obviously didn't get the settings right as the centre section was over-exposed and there was evidence of ringing.  Last night was also pretty hazy again so I didn't expect too much.  But it did give me a chance to experiment with the settings and the frame rates, and compare it to my preferred settings with WxAstrocapture at 10 fps.  Did 15 2.5 min avi's in Sharpcap and 4 in WxAstrocapture and processed them all identically in AutoStakkert!2 and Registax 6.  It was fascinating to see the improvement as the frame rate went up.  And a matter of balancing brightness with the gain though I think I need to fiddle a bit more with the colour balance to get something approaching my best ones with WxAstrocapture.  But it will be interesting to see the results when the seeing is good. Best image here showing GRS and Europa.

[Coastliner]

CSM, could you do me a huge favour and post one of your best processed pics of Jupiter taken with the SPC900NC? I seemed to have hit a plateau as regards image quality and I'm beginning to wonder if I am chasing rainbows trying to improve. I may have hit the limit with my current setup. I realise that your scope is more capable than mine, but at least I may get an idea from one of your images. Can I expect more from my Nexstar 4se?

[JamesF]

These are using an SPC900 and my 127 Mak, so not a whole lot more aperture than your 4SE.

James

[Coastliner]

James, I'm stunned. I haven't achieved anything like that quality. It's good in a way, it shows I have a shedload more to learn.

Can you give me some pointers? What s/w do you use? What parameters on what imaging s/w?

I'm going into a darkened room for a little cry.

I hope you are going to tell me you took these whilst on holiday in the Atacama desert.

[JamesF]

All taken from home, probably less than thirty miles from you as the crow flies

I'm pretty sure I always used SharpCap with the SPC900.  I'd set the frame rate to 10fps, turn the gamma right down and leave pretty much everything else at default.  Then using the histogram I'd balance the gain and exposure time to get the histogram about 70% to 75% full.  I'd generally end up using the maximum exposure time I think.

Post-processing with AS!2 for stacking and Registax 6 for wavelets etc.

In terms of kit I completely stripped down the Mak, cleaned and reassembled it, getting the collimation as near spot-on as I could, bodged together a motorised focuser (because there isn't one that fits off the shelf) and used a Revelation 2.5x barlow with a 40mm (or thereabouts) extension in front of the camera.  In fact the extension was a kit Skywatcher barlow that was quite hideous to use from which I'd removed the lens elements.

Other than that, just huge amounts of experimentation and practice, and no regrets when I had to throw data away because it just wasn't good enough (which is a killer when you've spent three or four hours out for several nights and have little but experience to show for it).  When it's not working it's astonishingly frustrating.  When it does work it's brilliant  Focus is the real killer.  If you can't get good focus you won't get good images.  That was the real motivation for motorising the focuser.  The control it gives is so much better than anything you can manage by hand.

Oh, I used to do stuff like stick reasonably large stones in the eyepiece tray of the mount too, to help stabilise it.

James

[CSM]

Hi Cardiff James - if you look at my website you will see my images.  I used to do them with the NexStar 6SE with worked very well even in ALT-AZ mode.  The 9.25 is a step up but am always learning and experimenting.  Come to the conclusion that 2.5 mins is best for Jupiter.  And like the other James I use AS!2 and Registax 6.