Help Needed Please: H-alpha Imaging

[GC - South Aus]

G'day All,

Long time absent from the website as I have been super busy with work, with a lot of travel.

So I had a little time this Easter (Friday) to give my solar rigs another run. I have had some extreme problems getting my scopes (both H-alpha (Solarmax 40) and White Light (2" Lunt Solar Wedge on an ED80)) to get to focus, and I am still having issues!

Although it has been a long time between :cheers:, so it has been like learning this stuff all over again.

I must say I really dislike the hassle of attempting to focus outside and look at the laptop screen at the same time. Very difficult! Even with setting up a box around the laptop and the use of a large blanket, it is still proving a struggle.

Anyway the attached H-alpha image is taken from one of the 5 avi's I took on the Friday (all around 1000 to 2000 frames).

The setup was as follows:

Solarmax 40
SPC900NC Philips Webcam
SharpCap Imaging Software
Orion Skyview Pro Mount
Asus i5 Laptop

Processed in Registax 6 (1st Image)
Further processed in GIMP (2nd Image)

I managed to get some clear detail in the original AVI, but as can be seen I get this double/ghost like image around the edge of the disc. No matter how I try I can't seem to get a truly focussed image with the CCD chip, but EP view's are always pristine!

Has anybody got any advice for image settings for this setup in any of the following programs:

Philips Vlounge
WxAstroCapture
SharpCap

I am considering looking at KCCDTools 3, anybody use this and what do they think?

I am keen for any advice in relation to solar imaging as I seem to be struggling to make any further advancement in this area.

Thanks for looking and advice.

Kind Regards

Gav

:)

[GC - South Aus]

Please bare with me as I am having difficulties uploading the images.

Will be uploaded shortly.

Gav

Images Added

[pw]

I'm no expert but it looks like the exposure is excessive. The sun is blooming into the dark surrounds. Is it possible to shorten the exposure time, reduce gain or similar to cut down on the blooming effect?

[GC - South Aus]

G'day pw

I can't even remember what the settings were. But I remember it was difficult getting any detail on the screen until I pushed up the exposure. I agree that it was probably excessive.

That is why I am looking for settings advice from people with similar setup (I.e. SM40 and SPC900NC webcam). I just find it difficult to find focus and get any real detail on lower settings.

I must also concede that I did not record this in the best part of the day, as it was around the middle of the day and sun was high in the sky.

Any help on settings or what I should expect to see with good settings (I.e should I be able to see any surface detail, or just a muddy dark red disk) would be greatly appreciated.

Cheers

Gav

[MGTechDVP]

Hi Gav,

To me it looks like your gain is too high (and/or not stacking enough frames) and your focus is out.

I find I can get the solar disc at 1/1667th second exposure on the DMK41 and for the prominences I need to drop the shutter speed to 1/15th - 1/50th (depending on the brightness and size of the flare.)

When focusing, drop your gamma levels down to 50%, it increases the contrast on the screen substantially and it makes it easier to judge when you've hit the best focus.

Mariusz

[pw]

I'm just beginning with solar imaging too and I too find focussing far from easy on the laptop screen. Thanks for the tip on adjusting gamma for focussing Mariusz.

[GC - South Aus]

Hi Mariusz

Thanks for the advice and settings.

This is the kind of thing i am looking for, such as settings and software advice.

Will give it a go when I have a chance next.

Cheers

Gav

[JB80]

Not a bad effort. :)

I still haven't found a better method to use for helping with focus on the screen than a towel over the head and laptop. From there you can try detuning the scope to try and shift it more to show the sunspot regions as they have better contrast and focusing on them before tuning back to the proms/filaments.

Are you using a UV/IR filter too?

Also if you can zoom in on sharpcap that may help. I use IC capture mainly so can't help with exact solar settings for the other software.

Now I may be wrong here but is your SPC900 colour or mono?
If it's a colour cam you are probably recording too much data, only the Red channel is useful in Ha imaging and all the G & B channel will be doing is running interference.

If you can take a single frame from the avi in GIMP and turn it to greyscale/B&W you can then split the channels and should see that the R channel is the one with the detail.

I believe there is software like "RGB split" that may be able to help to but I can't say I have used it to pass on any tips.

I may be wrong on the above but I think the application for a colour cam would be similar to using a dslr and Ha scope.

[GC - South Aus]

G'day Jarrod

Some great advice, thanks.

The image is without IR/UV filter. Should I be? I generally only use this type of filter for planetary imaging.

The spc camera is colour. I think it can be turned to b&w during recording as well, but not true mono.

I have recently acquired a DMK 31 AF 03 which is also a colour camera, so I am planning on using IC Capture too. But have no experience with it yet.

I have never used an RGB image splitter program before. I also never thought of reducing the B & G channels in GIMP either. Although that would be quite time consuming.

Thanks so far to everyone for the advice, I am looking forward to getting out there when I can (between work req's). But guess what! Looks like rain and cloud has set in the for next couple of days. :cloudy:

Cheers

Gav

[JB80]

Hi Gav,



I have seen both cases argued, some say you don't need one for Ha imaging and others swear by it.
Now you may not need one but personally I feel that as long as it doesn't introduce any type of artifacts to the image it may help with contrast.
I always use mine and I don't think there is any harm done, I'll try without next time just to see if I can notice a difference.



I have still seen some good Ha shots with a colour SPC before so don't let it deter you at all, but as most of the detail comes in via the Red channel it will make things tougher but certainly not impossible.

I haven't really used a channel splitter program either, I downloaded 'RGB split' once and then decided to go and have a lie down but it may be a solution, easier than doing it individually in GIMP anyway?
I don't know if there is an easier way, there normally is.

The DMK should be a good cam too and coupled with IC capture it won't be so hard to get used to. When you start off in IC capture the standard defaults, on mine are "Gain 260" and "Gamma 100" are enough to get you up and running with good results.
It's just a shame that IC capture doesn't run the SPC.

Still you are well on your way and the first pics I would of been happy with when I tried the SPC900 out.

Hopefully it clears up soon and look forward to seeing more pics too. Especially the white light.