Washed out Images!!

[Barry]

Hi - can anyone help me with imaging Jupiter? I tried last night but was unable to reduce the brightness enough to see any detail at all. I was using a C100ED with 2x Barlow and an SPC880 webcam (recently purchased from Morgans!)

I used K3CCD Tools3. I tried to reducing the brightness by decreasing the brightness and gain controls and increasing the frame rate to max. I was able to get reasonable images of the moon which you would think would be brighter but no luck with Jupiter.

It's so embarassing with all the great images on the forum

Any advise gratefully recieved.

Barry

[barkis]

I had my DMK21 on Jupiter last week, and I had the same trouble.

I didn't expect anything great, as the skywas pretty Naff.

I was getting a lot of double image with no detail visible.

I know the 6" f8 Refractor I used needs collimating, because I had the lens cell off a while ago to clean it up a bit, and I had the push pull screws out to clean them up. There was no way it went back into the tube in a collimated state. Indicative of the haphazard way I go about things I'm afraid. Besides, if it was easy, everyone will be doing it.

I learned one thing, that the planet is a fair size at f20, so next time, I will have the scope in a fit state to be serious about things .

Ron.

[brianb]

You're not trying to use auto exposure are you? Turn it off ... auto anything is an instant recipe for buggering up any sort of astro imaging!

[Barry]

Brianb - No, although I will admit to trying the auto setting in desperation. I just could not understand why the moon came out OK.

Barry

[bus_ter]

I don't know about K3CCD tools (I use SharpCap and it works for me).. but I don't adjust the brightness using the 'brightness' slider I use primarily the 'Exposure' and 'gain' controls and can easily darken Jupiter right down. Also use the 'gamma' control to darken and boost contrast.

[Barry]

Thanks, I think I will try Sharpcap.

Barry

[Clayton]

Sounds very much like an auto exposure control problem to me

[Peter Drew]

I've got a feeling that Jupiter, area for area is actually brighter than the Moon which might explain your difference.

[cathalferris]

The auto exposure algorithms use a type of averaging of the full frame to get the required contrast and brightness. Generally the brightest parts of the image will be saturated, and if the frame consists of a dark field and one tiny bright part, the driver will try and get the most detail from the large expanse of dark, instead of the detail in the bright portion.

When recording the moon, you've got a lot more of the frame covered by the lunar surface, and the algorithm works better in that case.

Manually controlling the exposure and gain will probably give you what you need.

[Peter Reader]

Increase shutter speed to around 1/250? Anything lower on my toucam and I get a burnt out white blob. For 2X barlow I'm on 1/30.

Hope this helps.

[Hoshikomi]

Barry

I always start with the following settings:

- Brightness: 50%

- Gamma = 0 (or near to 0)

- Saturation = 80-90 %

- Gain = 50%

I then move the exposure slider until the histogram is 60-70% across and fine-tune with the gamma and gain. I use SharpCap as well and I much prefer it to K3.

Cheers

[Barry]

Thanks to all for your advise. I have now downloaded a copy of Sharpcap - it looks a lot easier than K3CCD!

Barry

[Peter Reader]

I must say I had issues similar to this with K3CCD tools, and they product key is just annoying. wxAstrocapture isn't bad if you need another one...