Can't get sun to focus SM40 - Help Please

[gavcol]

Hi Everyone

I have spent all day trying to get my spc900nc Philips webcam to focus on my Coronado sm40 solarmax. I have also tried using a 2x shorty Barlow Telenegative and a 0.5 focal reducer to try and get the whole disc without luck. Visually focusing is no problem, using a Meade 8-24 zoom EP. The views are stunning with this EP!

Came close once with the webcam but always seems to just fall short of any detail. I have tried sharcap, wxastrocapture and Philips vlounge software without luck. It seems like the chip wants to get closer than the focuser will allow.

Any ideas? Is anyone else having this same problem? Is this a common problem with this setup? Am I a numpty?

Anybody got any good standard settings for the above software for sun imaging with this setup?

:help: please

Cheers

Gav

PS I have had no problems with the Meade electronic EP in achieving focus and magnificent detail with this setup.

[Merlin66]

Gav,
First of all if you want whole disk images with a webcam you definately need to use the reducer. The webcam chip is only 2.8 x 3.7mm this means a maximum efl of around 250mm!
Focusing.....practise, practise and more prac....
Have you tried Registax to stack your AVI's?? It certainly helps to pull out those fine moments of good seeing.

[Cam]

I had success reaching focus with a phillips spc900nc in a pst. I had to unscrew the nosepiece off a 2x barlow and screw just this directly to the webcam adapter.

[gavcol]

Hi Merlin

Thanks for your reply. Maybe I am expecting to much from my images, I can see prominences and CME, I am just not getting any granulation or filaments on the surface. It's just orange in colour! Have tried turning the colour to b/w but still can't get any detail.

Is this the difference between the electronic video EP and the Philips webcam? As stated previously I managed to get filaments and granulation to come up very easily on the electronic EP on the tv screen compare to the spc900nc. Just no detail at all with the webcam.

Or could it be my settings on my software?

Cheers

Gav

[gavcol]

Thanks for that Cam I will give that technique a go next weekend.

Regards

Gav

[sheeny]

The other thing to watch is your camera nose piece. Some nose pieces have a shoulder on them and others don't. I had to grind the shoulder off one of my nosepieces and shorten the nosepiece to get my camera close enough to focus. i.e. front of camera touching to top of the EP holder.

Al.

[Jen]

Good luck Gav ;) it looks like we will be both checking out each others thread very closely hehehehe

[gavcol]

Hi Al

Yes, this sounds like an idea. It was something that I having been thinking about today. But I only have the one plastic nosepiece and it works well with all my other my other setups so I didn't want to cut this one down. Will have to invest in a new one off eBay.

How much did you need to shorten it down to?

Cheers for the advice and it re-affirms my line of thinking.

Regards

Gav

[gavcol]

Hi Again Jen

Yes I will be checking out your thread ;).

Was very surprised to see your entry pop up only a few mins after mine. But I guess it's not that surprising as it was a great day for it (well in Adelaide) and whilst my imaging sucked, I managed to get sme great visuals in!

Best of luck to you:thumbsup:

Gav

[asimov]

Hi Gav. Check this thread to see how much I had to shorten my adapter by. I'm not sure if your scope is equal to my old PST or not though but sounds like they both need the same kind of camera/adapter mod employed.

http://www.iceinspace.com.au/forum/showthread.php?t=103073

[Merlin66]

If you have the standard SolarMax 40 OTA you shouldn't have the same restrictions that occur on the "black box" PST..
There should be enough backfocus with the helical focuser??

[gavcol]

Hi Ken

Back focus is not the problem it appears as though it needs to get in closer.

As I pull the focuser I loose any kind of focus, but as I push it inwards it becomes more cleaner/sharper but not enough before I run out of both inward movement and fine focus.

Any further thoughts?

Like I said in a previous post am I expecting to see too much on my original image whilst capture? Or is there no real detail visible at all whilst capturing? When I used the Meade Electronic EP there was plenty of detail visible on the screen whilst capturing.

Cheers

Gav

[sheeny]

I can't remember now... maybe there's details in a thread here, so I'll do a search, but from memory I had to take 3 to 4mm off my nosepiece.

Al.

[Merlin66]

Hmmm
I have the SM60 scope and didn't find that issue...I can only suggest the solutions being mention on the PST thread - shorter shoulderless adaptor.
There should be some detail visible during the capture - the seeing conditions can cause the image to move in and out of focus and jump around..the processing with Registax smooths all those out and picks the "best" quality for the final stack.
Post a couple of your images...

[sheeny]

Sorry Gav, while I read you post, I obviously didn't fully digest it. I was thinking PST not SM40. I don't have experience with an SM40T, so if the short nose piece fixes your problem, that's great, but just in case I've had another thought...

What are you trying to focus on? Are you trying to focus on the detail on the disc, or on the edge of the disc?

If you are trying to focus on the detail on the disc, but your etalon is poorly tuned, you will not see any detail, so you may think you are not getting focus.

What you need to do is focus on the edge of the disc. When that is sharp, then adjust your etalon to bring out the detail.

Al.

[gavcol]

Ken, I didn't actually end up capturing any today as I spent all my time trying to focus the live view on the PC whilst hiding under a small table with picnic cover over it :screwy:

In hind sight should of done some :confuse3:

Well I have learnt a bit today so will try next time I have a spare moment to get setup. Unfortunately work is going to get in the way of things for the next five days. As you can tell I didn't win the 20m lottery ths weekend :sad:

Regards

Gav

[gavcol]

Al

I tried both, had greater success with the edge of the disc though. Managed to get a few prominences focused, but I still felt that the detail was lacking. Maybe this was more to do with my software capture settings which I am struggling with a little. All my best focussing was achieved with the focuser all the way in, which makes me think I should give shortening the adapter just a little more a go :shrug:

Regards

Gav

[Merlin66]

My "solar observatory" is an 80L grey plastic tub on the fold up table...gaffa tape the lid as a hinge and hold it open with a bit of fence wire...laptop etc inside it and an ol' dark sheet flipped over the lot.
Keep practising....
Onwards and upwards

[Jen]

Haha your solar observatory sounds awsome :rofl: pics please lol

[Merlin66]

Basic but highly functional!

[asimov]

That's pretty high tech Ken....If you saw my setup..;)