Three works in progress

[strongmanmike (Michael)]

Meeh thought I'd show'em...it is a slow and laborious task with a big heavy portable kit so who knows may never finish them before the new scope arrives so here are three works in progress:

NGC 6872 galaxy group in Pavo

Horsehead (single 10min sub )

NGC 1316 galaxy group in Fornax

bottom line of thumbnails in this Album

Will I finish'em

Mike

[strongmanmike (Michael)]

Ooops. I forgot to un-bar two of the albums, they wouldn't have shown up, doh, sorry

Mike

[tornado33]

Gee that horsehead shot is impressive for just 10 mins. I reckon after the hours of data you will likely gather, it will be a spectacular result
Scott

[strongmanmike (Michael)]

Originally Posted by tornado33

Gee that horsehead shot is impressive for just 10 mins. I reckon after the hours of data you will likely gather, it will be a spectacular result
Scott

Yeh did that this morning Scott as the sky was brightening, this was the only sub not affected by the rapidly forming high cloud and lightening sky - doh, it wasn't calibratable properly as I must use median combine which requires at least 3 subs to work. I mainly did it as test to see the effectiveness of the new low reflection Astronomik Ha filter...looks to be the goods Not sure what that vertical line on the left is above Alnitak nor the horizontal one coming off Alnitak and meeting it perfectly...? . Thought the verticle one was a sattelite but the way it perfectly meets the horizontal line seems uncanny..?

Mike

[ballaratdragons (Ken)]

DROOOOOOOL!!!!!!! http://www.pbase.com/strongmanmike2002/image/123634922

[gregbradley]

Fabulous images Mike. Amazing resolution on that NGC1365 lookalike galaxy.

The vertical and horizontal line looks like a reflection of the filter from the bright light of Alnitak.

I suggest blackening the edges of your filter.

I use a black permanent marker pen. I am told you can get Testors flat black paint in a pen (model car paint). I'll follow it up as Tim Khan knows where you can order one. It'd be a worthwhile project to blacken all your filters. It all helps. There is a paper on the Edmunds Scientific site about the effects unblackened edges can cause. I haven't read it myself though.

Greg.

[multiweb (Marc)]

That Ha HH looks very promising. Watching with interest.

[Tom Davis (Tom)]

Originally Posted by gregbradley

The vertical and horizontal line looks like a reflection of the filter from the bright light of Alnitak.

I suggest blackening the edges of your filter.

I use a black permanent marker pen. I am told you can get Testors flat black paint in a pen (model car paint). I'll follow it up as Tim Khan knows where you can order one. It'd be a worthwhile project to blacken all your filters. It all helps. There is a paper on the Edmunds Scientific site about the effects unblackened edges can cause. I haven't read it myself though.

Greg.

I heartily agree with Greg's advise. Once you start shooting with the corrected newt these reflection lines will be all over the place. Blacken the edges of your square filters.

Great images, BTW!!

Tom

[gregbradley]

Here are 3 locations I found to get Testors Paints (model planes, cars hobby paints)

http://cgi.ebay.com.au/Testors-2547C...item230917db15

http://cgi.ebay.com.au/Testors-Model...item19bd8f5018

http://www.testors.com/products/136840


Then again just some flat black paint and a thin artists brush would do it from Bunnings.

I have a 4L can part filled left over from spraying the inside of my observatory if you want some. I can pour it into a jar and mail it to you. How's that for service eh?

Greg.

[strongmanmike (Michael)]

Originally Posted by gregbradley

Fabulous images Mike. Amazing resolution on that NGC1365 lookalike galaxy.

The vertical and horizontal line looks like a reflection of the filter from the bright light of Alnitak.

I suggest blackening the edges of your filter.

I use a black permanent marker pen. I am told you can get Testors flat black paint in a pen (model car paint). I'll follow it up as Tim Khan knows where you can order one. It'd be a worthwhile project to blacken all your filters. It all helps. There is a paper on the Edmunds Scientific site about the effects unblackened edges can cause. I haven't read it myself though.

Greg.

Hmmm..? reflections usually lie in line with the bright star don't they? The horizontal one lines up but the verticle one doesn't..? The fact that they are perfectly verticle and horizontal seems very strange too..?

If it is indeed a filter edge reflection, is it just an issue with the square filters becasue there were never any odd reflectiions with the latest gen Astronomik round filters I sold with the PL11002..?

The good thing is, while there is a vague hint of it there is no major circular reflection around Alnitak, so that bodes well at least, this was my first concern.

Mike

[multiweb (Marc)]

Greg's explanation makes perfect sense. Would be even more dramatic with square filters because you have a straight edge working as a mirror. More info here.

[TrevorW]

Keep em coming Mike

[strongmanmike (Michael)]

Originally Posted by multiweb

Greg's explanation makes perfect sense. Would be even more dramatic with square filters because you have a straight edge working as a mirror. More info here.

Hmmm? After 12 images with the new filters and no sign of any reflections at all I thought I had escaped this perceived issue ...next session I'll try again and move the the scope between subs and see if they are a) still there or b) move...?

Looking at the lines again, the verticle one isn't actually perfectly verticle after all but the fact that it terminates right at the shorter horizontal one is rather coincidental...? Maybe there is optical interference at that point and this cancels both light rays out as they intersect as they pass longitudinally through the filter glass

Mike

[marc4darkskies (Marcus)]

Very impressive Mike - the detail in the galaxy groups is superb. And that camera of yours is definitely a keeper - the single sub horsey is very clean (except for the cosmic ray hits).

Cheers, Marcus

[gregbradley]

Try blackening the edges and chances are that will disappear. It was near Alnitak which is probably the worst reflection causing star in imaging. As to the physics of reflections - I think that can get pretty complex pretty fast.
Its not a comment on the brand of the filters as all filters have this issue. I am not aware of any of the filter manufacturers blackening the edges of their filters. It only takes a few minutes to paint the edges with a permanent marker. Just be careful, obviously not to get it on the main face of the filter but it does wipe off if you make a mistake, just do it fast before it dries.

I saw a similar reflection on a CDK17 image of mine recently. Only on a couple and it was also near a bright star and my edges were blackened but only with a permanent marker and perhaps a few areas weren't perfect. It was hard to see but it was there on a couple of subs. There was also some moon present.

Probably square are more prone to trouble as it forms a straight edge rather than scattering it everywhere with a circular filter. Easier to see the resulting reflection.

This blackening of edges is old data. I am surprised filter manufacturers don't do it. Eyepiece manufacturers have been doing it for ages. Televue eyepieces all have blackened edges of lenses.

Greg.

[spearo (Frank)]

Looking good so far
cant wait for the final product
frank

[Bassnut (Fred)]

Well, the single sub Horseheads pretty hohum, specially the duff colum, or what ever the right angle line connecting the big fuzzy star is. Mean or sum combine might have helped on that sub , dunno why you bothered posting that, given the standard we are used too . Umm, what does semi-calibrated mean .

The NGC1316, well, soso, but some nice odd galaxys there.

What is a supprise tho, is the NGC6872 crop, the galaxy slightly left/up looks very interesting indeed, pops right out, most enjoyable. .

[strongmanmike (Michael)]

Originally Posted by marc4darkskies

Very impressive Mike - the detail in the galaxy groups is superb. And that camera of yours is definitely a keeper - the single sub horsey is very clean (except for the cosmic ray hits).

Cheers, Marcus

THanks Marcus

The pavo cluster galaxy is a real gem, there is more detail in there I just couldn't get any more, besides in a grouping like this if you do too much decon on a single galaxy it starts to look out of place, almost too sharp

With this in mind I redid the decon layers on NGC 1316 and it has come out better now, the very faint stars I thought were lost were actually there, shame I can't do this for the whole image as there must be a lot of stars fuzzed out by the seeing that could be brought back even if only slightly..?

Mike

[Octane (Humayun)]

The framing of the Horsehead is just sublime.

Looking forward to the final rendition of that one!

H

[strongmanmike (Michael)]

Well, the single sub Horseheads pretty hohum, specially the duff colum, or what ever the right angle line connecting the big fuzzy star is. Mean or sum combine might have helped on that sub , dunno why you bothered posting that, given the standard we are used too . Umm, what does semi-calibrated mean .

Ah sigh...a work in progress, a work in progress, I am not so proud that I must only show perfect and completed images, thought some might like to see what I was working on, no harm in that, is there?....

Semi-calibrated means because I only had one sub to work with I couldn't use your suggestions, as it were, as I can't do any "combining" with a single sub.

The NGC1316, well, soso, but some nice odd galaxys there.

Ah yer just jealous cause the field is sooooo massive with more galaxies visible than you get stars in your images...yet when zoomed in I can still get this read it and weep, and that's only 75% full res too nah nah

What is a supprise tho, is the NGC6872 crop, the galaxy slightly left/up looks very interesting indeed, pops right out, most enjoyable. .

Ah thanks I am glad something was good for you