View Full Version here: : Eta up close
Alchemy
23-05-2008, 10:27 PM
Just a quickie before the moon ruined the view, only shooting Eta because its on the meridian 45 mins was all i had to work with. Just getting a feel for the new camera
Shot with QHY8 and 12 inch newt.
Deliberately left it a little light and not clipped to black as its in a brightish part of a nebula where there is no black. Processed to show the "waterfall"
Thanks for looking.
clive
Hi,
A nice in your face closeup, looks good :thumbsup:
I have a question though, normally Eta is very red with an astro cam and this image looks DSLR'ish in colour?
Paul
Bassnut
23-05-2008, 11:49 PM
Very nice Clive, thats the kinda real close up I like. Good detail there, and it seems youve got your rig guiding well. For only 45min, thats a top effort.
Dennis
24-05-2008, 07:10 AM
An excellent close up Clive. I cannot recall ever seeing rounder stars than I have in this image – top stuff.
Cheers
Dennis
Alchemy
24-05-2008, 10:05 AM
thanks for looking guys.
Zuts, i know its got plenty of sensitivity in the Ha department and having shot cats paw (which is really red) im happy enough to assume that a large amount of other spectra is there changing the color, as to why its different to other cameras...... :shrug: i know Scott(tornado) put up one very red one recently , i think the filtration might have done that. Still very happy with my new toy:)
put up a small of whole image so you can see overall.
Details of shot. Gain 50 offset 117 , i actually only had 7x 5 min exposures to work with in the end becuase of an issue with frosting (now FIXED).
Bassnut, thanks for comment. Not my usual to put up so close in but this one turned up well, the guiding seems to vary from night to night, i suspect its something to do with the calibration initializing in PHD as on occasions i have redone it because it wasnt tracking well enough and then after a quick recalibration ....perfect, i have had custom mounting plates made to minimise flexure...... now if i can get the detail in all my shots like this:)
Dennis ....round IS beautiful, one of the roundest ive seen too (from my images)
Alchemy
24-05-2008, 10:10 AM
forgot the pic ...sorry ZUTS (cant get the EDIT button to work???????)
Thanks Clive,
The image is very good, very good tracking at that FL as well. It's probably just a combination of the moon, filter, nebulosity and focal length. Looking at the photo Peter Ward posted with the 20 inch RC that has red but lots of other paler colours from the nebulosity as well.
I am just posting mine for colour comparison, I was happy with my reds, your photo is not so red, godamm isnt it hard to know what the colour should be when you are just starting out and finally get some good gear. Equipment learning curve, processing learning curve, its all fun :)
Paul
Everything is done in the software with processing. You can make it as red as you want or as black and white as you want.
Just need to play with it until it appeals to you.
Heres a 10 minute quicky on Photoshop.
Didnt have much to work with given the size and format, but you should get the jist of it.
Theo
Alchemy
25-05-2008, 08:17 AM
Thanks for your comments guys.
gamma..... processing can make or break an image (providing youve got good data to start with) there are those like jase whove made it a bit of an art.... i will get there slowly.
zuts..... yes yours does have more red.... what is the true color :P stuffed if i know. my theory is more or less this you should be able to see some star color variations, ie some yellow and some blue, if all your stars are red its too far..... also some areas of the image will have little or no nebulosity (eta is a bit of a tough case as its so big and dense) one can do a levels color balance at a point that should be grey. i suspect chips would vary so some will produce a slightly different result. At the end of the day once youve altered an image so that it can no longer be used for Astometry or some other scientific application, it falls into the realm of pretty pictures, and as long as it looks nice to the owner thats what counts...... Most non astro people would not have a clue and be impressed anyway.
i have played with the image some more and shown accordingly little interesting bits (this is without a doubt the best eta image ive produced so i am a bit thrilled about it)
i will no doubt play with it some more but thats it for now
clive
strongmanmike
25-05-2008, 10:10 PM
I agree Clive, imaging is about imaging and absolute correctness is not that important really.
I like the crops you have displayed Eta is sure one interesting bag of tit bits.
The only critisism I have is that the stars don't look asthetic to me, they are very hard edged and look like ice cream lid cutouts to me. The original image had the stars with a softer look. Perhaps they were slightly out of focus and you have pushed hard to sharpen the nebulosity, which has handled it, but the stars didn't? So while the nebulosity looks good the stars have taken on a processed hard look.
Not a bad thing just an observation and as you say, the best effot for you to date so good on you man! :thumbsup::thumbsup::thumbsup:
Mike
I like the last post Clive. The panel shows various aspect and in some cases what would appear to be different processing. Perhaps the processing was identical for all and they are crops, but there are differences between them. Indeed as Mike points out, some stars look a tad crunchy - perhaps you drop the white point too low before using levels or you used a "tricky" S curve in PS to give the neb a contrast boost (if you do this, mask the stars). Anyway, I think its a fine effort and sign that you are progressing deeper to the dark side of dealing with 16-bit data (and the benefits it brings). Well done.
Alchemy
27-05-2008, 10:09 AM
Hmmmm that bad , all the ice cream lids i have are square.
Any better?
strongmanmike
27-05-2008, 10:21 PM
Yes I think that's better, now the stars are softer and more glowing.
When I said your stars look like icecream lid cutouts I meant they look like circles cut out of white ice cream lid plastic ie hard edged blank white circles..if that makes any sense?
Mike
iceman
28-05-2008, 06:57 AM
Excellent results, Clive. The QHY8 will be a great performer in your hands. The right scope with the right techniques with the right processing will deliver quality!
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