Horsehead region @ 280mm f5.6 (+/- LP filter comparison)

[dugnsuz]

Hello all...

2 clear , moonless nights in a row put to good use on the Horsehead.

First night I used the Hutech LPS filter and got some annoying reflections from the bright stars in Orion's belt.

Second night as an experiment, I tried same area without the filter.
Some reflections persisted, but nowhere near as obvious as with the filter.
Hmmmmm!!!!:confuse3:
Looks like this filter shouldn't be pointed at bright stuff!!!

I've attached some pics to compare along with final version.

#1 10min sub + Hutech LPS filter
#2 10min sub No Filter
#3 24x10min combined from filtered/non filtered subs.

Image details…
Canon 40D (modded)
Canon 70-200mm f4L lens + 1.4x Extender, 280mm @ f5.6
Skywatcher Synscan EQ5 mount
Autoguided with PHD
iso1600, ICNR on, Flats.

High res...
http://s327.photobucket.com/albums/k461/doug-robertson/?action=view&current=13a.jpg


Cheers
Doug:thumbsup:

[RobF]

Wow - very nice detail coming through there Doug! Love the look of the flame neb too.

Wish I could get to 10min subs in the city. Fogging seems to get problematic over 5mins even with IDAS LPS in place for me. Sigh.

[multiweb]

I quite like the one sub without the LPS filter. The final stack colors are real nice.

[Ric]

Wonderful images Doug, you've done a fine job with them.

Cheers

[AlexN]

A-W-E-S-O-M-E

As always Doug!

Cheers.
Alex.

[xelasnave]

Super love the result
alex

[dugnsuz]

Thanks for the comments chaps:thumbsup:
I processed this image before taking the kids out swimming in the afternoon, when I logged in this evening I thought that the final version looked really garish! May have to repro!!
There's a good final image in amongst those 4 hours worth of subs hopefully!?
Cheers
Doug

[AlexN]

I noticed in the bottom left of the full frame images you also caught hold of M78! Shame it wasnt fully in frame!! would have been a nice addition to a great field of targets!

[Tandum]

Makes ya wonder why we use filters at all.
Your no filter sub looks just fine if not better than the other.
I guess they do the job when the moon is up though.

[xelasnave]

Yes but we saw it in the day time first so it looked less so ..noticably wilder at night...mmm post two of all images select if you are viewing night or day... Have another go well worth it I play with data for ages.

Still great going

alex

[dugnsuz]

Aaahh Robin, you're just trying to justify your no filter policy!!:P:lol:
The no-filter sub doesn't have those annoying "ghost" reflections granted, but the same halos persist around the brighter stars in the belt on both images. I prefer the filtered sub as the stars are a little tighter and there's less background noise. I found the processing of these filtered subs a bit smoother and easier in comparison too. As for the reflections, the PS healing brush is a wonderful thing!
I'll do a processed side by side soon. I think combining the 2 sets of subs was a mistake.
Cheers
Doug:thumbsup::thumbsup:

[Craig_L]

Those side by side processing comparisons will be interesting. Wonder whether you would get less flare without the 1.4 extender?

Keep 'em coming Doug.

[dugnsuz]

I'll give that a go tonight Craig.
I've removed the High Res link for now - I overprocessed it by miles! Lost all structural detail in the Ha nebula behind the horsehead.

Flare/reflections were present in 200mm shots without the 1.4x extender too.

Cheers
Doug:thumbsup:

[davewaldo]

A silly question, but I assume your using the lens hood?

The canon lens hood is made to work at 70mm so maybe you could extend the hood with some black card (to the 280mm limit) and see if it makes a difference.

It looks like the reflections are from something in the FOV so this probably won't help. But its cheap and easy to check. :)

Awesome shots too! I love these wide fields!

[dugnsuz]

OK, here is the comparison of Filtered and Non Filtered Stacks

Both, 10x 10min subs, iso1600

#1: Filtered
#2: No Filter

Both stacked in Images Plus (Average Combined)
Same processing in PS, Levels/Curves and 30% Minimum Filter

I prefer the Filtered one - what do you think?
Shame about the damned ghostly reflections though!
:thumbsup:

[dugnsuz]

Well Dave,
Hadn't thought of that!
A nice little project I reckon - Cheers for the heads up.
Doug

[dugnsuz]

Final Image + High Res Link...

http://s327.photobucket.com/albums/k461/doug-robertson/?action=view&current=13a.jpg

[monoxide]

nice one Doug, hi-res repro is much better :thumbsup:
i've tried the HH a few times and failed badly :P

nice comparison between filtered/unfiltered too btw.

[Jen]

Very nice pic Doug :thumbsup::thumbsup:

[dugnsuz]

Thanks Tj, failure on the HH is not an option!!!!:lol:



Cheers Jen - thanks for looking:)

Aw ra best!
Doug:thumbsup: