My test object again ETA

[EzyStyles (Eric)]

Hi Guys,

Everytime I get some sort of new equipment, I always point the scope to ETA for testing and comparing the differences thus that is why I always post ETA shot. well the Baader UV/IR filter is now fitted in my imaging train. hopefully no more ETA

10 x 5 minutes at ISO 400 with the C10 F4.7 and canon 300D modded. Also use baader MPCC and UHC-S. autoguided with Orion ED80 with the Meade DSI II.

Cheers

[richardo (Rich)]

Hi again Eric,
I agree, the brighter objects are great to test new gear and see what's what in a relatively short time.
I always seem to go for M42.... well, it seems to be in the right area of sky when I buy something new...

I like the lovely detail you've picked up along the Keyhole wall... !!

Just a thought, have you ever thought (or heard) of doing a G2V calibration...ie do short images on a G2V solar analogue star (Alpha Centaurus is one),,, the same spectrum as our own Sun and weight your RGB's so that the star turns out white. This same weight can then be applied to all your images. It all changes when using different scopes so it has to be done again.
Chuck Shaw, Al Kelly, Ed Grafton and Richard Berry did much work in this area to produce "true" colour images.... I say "true" with my tongue in my cheek, but it can get you consistency with every image... plus using extinction factors multiplied to your rgb weight......... but of course artistic license comes into play with what we do, and depending on how much fritzing around you want to do but it's an interesting concept all the same... here's a link if you'd like a read..
http://www.ghg.net/akelly/artdraf7.htm

I know they did it with individual filters, but you could also apply the same reasoning in PS or similar software with the 300D images, just use the channel mixer a bit.

Also Steve Canistra has great tutorials on lots of stuff. He's a great imager and much can be gleaned from his tutorials. Here's his link if your interested...
http://www.starrywonders.com/

Glad you had clear skies last night, certainly made the most of it!!!
My area clouded over after a while and I ended up with only 12- 3min subs with a NE asteroid very slowly chugging across my M104 image.... it took an email to the experienced asteroid trackers from the CADG group to find its designation for me... as I am so unprepared when it comes to these little beggers!
It's amazing how many of these little wanders there are..... and so close to us.

This one I though I'd better get it checked out..... but very bright at 13 mag and super slow. Very close to us as well at only .988AU.

All fun though and keeps us from our beds...

All the best for now
Rich

[EzyStyles (Eric)]

Hi Rich. Thanks for the G2V calibration info. I was wondering not all stars are white though and how will that change the final image? theres heaps of reading from the link you gave me will definitely give it a go once i totally understand what it is all about lol

cheers mate.

[davidpretorius]

bugga that.....more eta penaut butter!

lovely image ezy.

where is the MOnocerus thingy in this piccie?

[richardo (Rich)]

Originally Posted by EzyStyles

Hi Rich. Thanks for the G2V calibration info. I was wondering not all stars are white though and how will that change the final image? theres heaps of reading from the link you gave me will definitely give it a go once i totally understand what it is all about lol

cheers mate.

Eric, the reasoning behind doing a calibration to a star with exactly the same spectrum as our own Sun a G2V type... is so that we can see the night skies colours as they could be seen if our eyes were super night sensitive, but in reality, we're using CCD's or cmos detectors that all way different from each other, then there's the scopes we use all different.

Our own G2V star makes the colours as how we see them.
So when you find the correct rgb ratio from a G2V star, thus giving you essentially a white star,(=amount of rgb =white) then for example stars that are red giants or new blue stars will appear in their correct spectrum instead of some weird colour. Your nebulas will display a correct colouration showing their subtle transitions and all the other objects will be calibrated as to their light spectrum.
You won't have to compare your images with any one else's on the net, as I guess many people do then adjust to these variations which sometimes appear wrong.
Like Mike said, many make the mistake of looking at the old emoltion images with red sensitive film.... these images looked all red..... and cranking the saturation up in red...

Any way Eric, read the write up on G2V stars, you'll see what I mean.

All the best
Rich

[Astroman (Andrew Wall)]

Nice shot Eric, love the clarity of it.

[EzyStyles (Eric)]

Originally Posted by davidpretorius

bugga that.....more eta penaut butter!

lovely image ezy.

where is the MOnocerus thingy in this piccie?

cheers davo. the what .. wha what?

[EzyStyles (Eric)]

nicely explained Rich. Thanks for the info. I normally do comparison on my colours with images by others. i guess they might not be correct themselves too. that will be my next challenge, to colour correct my images . would you think the UHC-S filter plays a part with the colours?

Thanks Andrew.

[richardo (Rich)]

Hi Eric,
as Baader claim, you'll only loose about 3% of transmission and it will block only LP emission lines.
When you do that first and only calibration, on the G2V star with your UHC-S filter in, you will be calibrated.
So ultimately, that's a good reason to calibrate your setup.

Once it's done, you'll be set to go on all objects and never have to worry about calibrating again.... Well until you change your scope or filters or image camera.

All the best
Rich

[EzyStyles (Eric)]

i have to do that G2V calibration then. If the settings are saved, all good cheers Rich.