Hells bells another Eta...... new and improved

[telemarker]

Last night I spent 2 hours collecting Ha photons from Eta Carina. Mount was guiding well using my new converted finderscope/guiding scope but there was a problem with the image download leaving artefacts in every sub and dark frame (see 100% crop). I think the culprit was using an external USB Hard drive for storing the downloads with my EeePC 701 - also the first (and last) time I've used an ext HD in the imaging process. :mad2:

[multiweb]

That looks like a readout problem. Basically the image download stream is interrupted. Save on local then transfer to your remote drive later. Real shame coz the image is gorgeous.

[mill]

Crap that doesnt look good,i hope it will be better when saved to a internal drive.

[DavidU]

That's a shame because the data is awesome.

[telemarker]

Thanks for the commiserations guys. It was one of those Grrrr moments when I saw what had happenned to the subs. But I'm satisfied with the way the new guidescope works and the way the mount is tracking, so all is not lost. This was a fill in while waiting for the primary target to rise but cloud put paid to imaging that (luckily really :P ). Time yet for another crack at it once all these clouds nick off.

[Peter Ward]

The interference is a problem, but sorry, you also need to work on the focus as the stars are little doughnuts....

stick with it :thumbsup:

[richardo]

Hi Keith,
congrats with your guiding, looks as though it's working well.

As Peter pointed out, your focus is off though. Your small stars in the cropped version haven't resolved to solid points of light.

I use to wait till my optics were well cool and spend at least a further half an hour checking focus in a binned mode to get my FWHM's to the lowest possible number then eye ball a full test image, magnifying to see if things were good.

All these little things will become second nature.
It's all fun!

Rich

[telemarker]

Thanks Peter, Rich. I see what you mean. I guess that is one of the problems with using a 7" EeePc screen for setup and capture. I might have to look at an electric focuser (already have a FCUSB I use with my SCT/Meade Zero shift focuser) for the refractor. Any suggestions that don't cost an arm or a leg that I can use with FocusMax?

[richardo]

Here's a cheap way to go and similar to what I did... not exactly though. You'll have to make some sort of a bracket to attach to your scope and couple to focusers shaft. With the below motor, looks as though you might need to remove the connector and retro fit to the FCUSB controller.
You will have to load the ascom driver that goes with the shoestring usb focus unit (FCUSB) then you'll be able to use Focus Max.. works a treat..

Here's a link to the el cheapo motor..
http://www.myastroshop.com.au/products/details.asp?id=MAS-051A

Here's a link to the Shoestring USB computer focus controller
http://www.store.shoestringastronomy.com/products_fc.htm

Think Bintel are agents for Shoestring products...

A bit of retro fitting but this is really the cheapest way to go.

Hope this helps.

Rich

[AlexN]

THe read out issue could be to do with the USB download speed too... I had similar problems when using that camera on high speed download mode...

Using a tiny screen shouldn't affect your focus accuracy if you use the information on the screen - use FWHM or HFD values to focus rather than how the stars look on the screen..

[telemarker]

Thanks Alex, I did better this time around:
1 - no external hard disk :thumbsup:
2 - put more effort into improving the focus :thumbsup:
3 - checked the download speed :thumbsup:
4 - threw money at the problem (bought a motorised focuser, yet to arrive) :screwy:

Heres the new and improved image. 2 hours Ha with 10 min subs, curves levels, greyscale, 30% darken blend with wavelet sharpen.

[Octane]

A marked improvement. Well done, Keith.

H

[telemarker]

Thanks Humayun. Are you counting the sleeps till your new toy arrives?

[Octane]

30 more to go. :)

I'm afraid I might not get first light until May, as I'll be back off to New Zealand for another photographic expedition.

H

[telemarker]

Oooohh. You're making it hard to be sympathetic though.

[strongmanmike]

Much better job Keith, amazing how one nights infuriating issues can completely dissapear the next...feels much better now huh? :thumbsup:

Mike

[AlexN]

Fantastic Kieth! Looks beautiful...

Humi!! $50 for you if you can stuff me into a suitcase and smuggle me over to NZ to join you on a photographic expedition!! :D

[telemarker]

Aye, that it does. Focuser arrived today so time to tinker.



Thanks Alex :D

[RobF]

Wow!
Spiffing Ha effort 2nd time around (said with english accent....)

[Octane]

So, both you /and/ Troy. How would you both feel about being squished into my luggage?

I did book a Rav4 today, so, once we get there, you'll be comfortable in the back seat.

H

[telemarker]

Why, thank you old chap. Tis time to adjourn to the library for port and cigars; eh wot?

[RobF]

:D :lol: