ic1396 Elephants Trunk Ha

[ChrisLX200]

Nothing much else to do with this weather other than process older data, this set taken in October and was not of the best quality. StarTools managed to get an image out of it though ;-)

Scope: Televue NP127is @ 660mm

CCD: Moravian G4-16000 @ 1x1

Mount: 10-Micron GM2000HPS

Guide: unguided

Fitlers: Chroma 3nM H-alpha

Data: 9 x 900s

The above image is compressed, it looks better at full resolution...

ChrisH

[MarsG76]

Excellent image...  seeing images like this is going to make me sell a kidney to go and get a CCD.

[michael.h.f.wilkinson]

That hi-res image is a stunner. Lovely detail

[Martin-Devon]

Yep - that's good!

[Freddie]

Nice wide shot there. Some pretty radical star shapes in the corners but as you said, it maybe wasn't your best data.

[laudropb]

Very nice capture. Thanks for posting.

[ChrisLX200]

Nice wide shot there. Some pretty radical star shapes in the corners but as you said, it maybe wasn't your best data.

Problem there is tilt - and no way of (easily) fixing it on the refractor. This camera will be moved onto a different scope anyway soon. No, the data is poor because it was taken around the full moon. I have 6 x 1200s OIII taken at the same time but that's pretty awful (bad gradients). Still, what the heck, I added it anyway ;-)

ChrisH

[toxic]

that is nice 

[Freddie]

Nice addition of colour. The moon is a pain and typical that the skies clear with a full moon!!!!

On the original I would have thought that tilt would give you elongation in the same direction across the image. The elongation direction is different in the different corners on that image.

[cfpendock]

That's actually turned into a nice image (tilt problems accepted!).  I always thought that Olll was a no-no for moonlight?  Normally I prefer the elephant in mono, but perhaps the moonlight does the trick?  I like it...

Chris

[matt-c]

That's fantastic chris

[ChrisLX200]

Many thanks for looking everyone!

Freddie: I'm just assuming tilt is the issue, seeing as I made no effort to align the thing but just screwed it onto the focuser (which is rather more extended than is sensible).

Chris: You're perfectly correct, and if I had any sense I would not have bothered trying for OIII around full moon :-) However, I was keen to see whether this Chroma OIII filter was going to produce halos or not so thought to test it. As it turns out not a good test as there were no really bright stars in the FOV!

ChrisH

[Freddie]

Chris, I have no idea what causes it but I really don't think it is tilt. If you look at each corner, the elongation is at right angles to a line drawn towards the middle of the image. Therefore top right they are elongated top left to bottom right but in the top left corner they are running at 90 degrees to this. I therefore can't see this being tilt. May be worth some further investigation. 

[AndyUK]

If you look at each corner, the elongation is at right angles to a line drawn towards the middle of the image. Therefore top right they are elongated top left to bottom right but in the top left corner they are running at 90 degrees to this.

I've seen a similar pattern associated with over-spacing on a (Riccardi) reducer...

Star shapes.docx

(... the only thing is, you're not using a reducer - It's an NP... )

(Maybe it might be worth having a look at a frame through CCD Inspector to see if that picks anything up...?)

[Pompey Monkey]

Those are a couple of truly gorgeous images, but I also like how you are (and will probably never be) not satisfied with them.

[ChrisLX200]

I think if I were going to keep it on the refractor I;d be more worried and try to find out what's happening, but with this current weather I can't use it at all anyway. With 9uM pixels it's not a good match for the refractor anyway and small stars are square (though I guess I could drizzle I suppose...). This camera will be attached to a rather hefty focuser/rotator ( http://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGGEMFOC) which has built-in adjustment for collimation and tilt etc., and the whole lot goes on the back end of an ODK12 - and that will take some effort to ensure the extension tubes are the correct length. So it's unlikely to get used that much on the refractor when all the rest of the gear arrives.

Yes Paul, I'm probably more critical of my images than anyone, there isn't a single one I can say I'm either happy with or I couldn't have done better! Most of the time I have to make do with less subs than I wanted, or that Moon has got in the way (again).

ChrisH

[Rodd]

Hi all--thought you might like to see my Elephants trunk in the Hubble Pallet.  I like the colors in the one above better--this is so green.  This has 9 hours of exposure as well.  Processing was very basic--nothing beyond a few stretches with power, saturation and color background.  I am trying to learn PixInsight--but it seems that no matter what I do--it makes the picture worse.

[Rodd]

Oh--yeah--I forgot--I used a Televue np101is--we're brothers.  Not sure why the np127is afforded a wider field of view--maybe its the CCD?    I used a SBIG STT-8300. You shot at 630 I shoot at 540, thought the zoom aspect would be less with the 540.  Mine was guided.  And I shot with a full moon as well!  It didn't seem to bother me too much--moon was in opposite quadrant of sky.  I am going to shoot this is RGB tonight for comparison

Clear skies (permanently)

[ChrisLX200]

Oh--yeah--I forgot--I used a Televue np101is--we're brothers.  Not sure why the np127is afforded a wider field of view--maybe its the CCD?    I used a SBIG STT-8300. You shot at 630 I shoot at 540, thought the zoom aspect would be less with the 540.  Mine was guided.  And I shot with a full moon as well!  It didn't seem to bother me too much--moon was in opposite quadrant of sky.  I am going to shoot this is RGB tonight for comparison

Clear skies (permanently)

Well the NP127is doesn't offer a wider field than the 101is, the FOV in this case is all down to the size of the CCD sensor - the G4-16000 has a sensor 37mm square (~52mm diagonal) and my image above was actually cropped down to about 70% of full size due to some frames not aligning with previous ones. This was some test data, pretty low quality and IIRC I was playing with doing meridian flips without a valid mount model! I just processed that part of the image which was intact.

ChrisH

[ollypenrice]

Is imaging about technical perfection at pixel peeping level or is it about the beauty and splendour of what's out there? For me it's the latter. I like these images. Sure, tune out the technical stuff as time goes by but don't throw out the baby with the bathwater. These are good images.

Olly

[ChrisLX200]

Is imaging about technical perfection at pixel peeping level or is it about the beauty and splendour of what's out there? For me it's the latter. I like these images. Sure, tune out the technical stuff as time goes by but don't throw out the baby with the bathwater. These are good images.

Olly

A fair point Olly. To me, my CCD + telescope are my space ship, I'm paying for the ride so I want a window seat and I want clean windows ;-)

This data set was really one of the 'first light' sets from October when I was testing both mount and camera, trying to figure out what I could get away with and what I cannot. As it turned out, if I remove and replace the OTA then although it seems to track OK there remains a big difference between tracking on the East and West side of the pier which the model needs to correct for, if I don't update the model then after a meridian flip this happens:

With a good model these subs sit on top of each other. So, a useful lesson learned there ;-)  Also tonight I looked more closely at each of these subs and I now get the feeling some of the second set suffered from slight field rotation. Anyway, from that lot you can see where the final image came from - the chunk to the right. The full frame is considerably larger. As soon as I'm satisfied there are no serious defects I'll leave it as it is and concentrate on collecting images rather than looking for problems.

ChrisH

[Rodd]

Here's the Elephant's trunk in RGB(Ha/L)--friends were wondering about the "real" color question and I thought I'd see if I could capture this nebula in RGB light.  Without the Ha/L addition, it was very dim indeed.  But the Ha only effects brightness here--it was not combied as a color channel.  I did power stretch saturation, so the colors are perhaps more vivid than what is real--A telescope wearing Rayban sunglasses!   I had to compress this file dramatically, hope it does not ruin it.

CS

[Rodd]

Yeah!! I finally learned how to make a master dark with CCDops and Nebulosity.  Here's the same data set of the Elephants Trunk in RGBHaL reprocessed with a master dark reduction.  Now I just need to learn how to process the preprocessed pics!!