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JGM1971

The "No EQ" DSO Challenge!

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34 minutes ago, wxsatuser said:

 

 

There is some in there amongst the red and colour mottle.

I took the liberty of a quick ABE in PI just to see.

 

 

 

 

That looks a bit more like the nebula, thanks, I had dismissed this as my imagination, I will target it again when it's back. 

Nige.

 

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14 minutes ago, The Admiral said:

Nige, that's what I find to be the problem with this short exposure stuff, is deciding whether you've got nebulosity or just noise :icon_biggrin:. You can definitely see structure in there though, amazing for just a single frame. And Mike's confirmed it. What happens if you up the contrast, does it bring out more detail, or is there just too much noise?

Ian

Ian, I think this was very high contrast, this is the original image I got before any manipulation.  

If anyone wants a cracking at seeing what's there please give it a go,IMG_2411.JPG

 

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6 minutes ago, The Admiral said:

You surprise me Ken, 'cos you got a super image of the North America nebula with the same sort of exposure.

I have no experience using PS, but can I suggest that you have a play with StarTools. May be it's a case of the devil you know, but ST does seem tobe able to reveal faint stuff.

Ian

I should have said. I think I took them with the SCT and only managed 8 or 15 second exposures. By the time my refractor arrived, Orion and his friends had moved to the front of my house where all the street lights are, so I will have to wait until Autumn for round 2!

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I didn't suggest the flexi 130p because the focuser is really not a good experience with a dslr hanging off it and the whole 70mm travel scope will be much easier to start with. Using a 1.6x shorty barlow means from memory I didn't need to drop the trusses but the helical is not easy to use or precise enough for dslr focusing.

You'll need an EOS t ring and t mount to connect your 450d, I got mine from FLO. That's the cleanest of connections. There is a chance you will also need a 2inch 1.25 extension which FLO also now stock as you won't be using the diagonal.

Edit: not sure what mount fixing the travel scope has but you may need something there. All my telescopes can fit on all my mounts they all have a built in dovebar.

Edit 2: I use a skywatcher L bracket to mount my bits that have a camera thread. 

Edited by happy-kat

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I just checked the exposure time , 20 seconds at iso 1600, not sure thats enough time to collect the light needed to bring out the nebulosity. 

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14 minutes ago, Nigel G said:

I just checked the exposure time , 20 seconds at iso 1600, not sure thats enough time to collect the light needed to bring out the nebulosity. 

I just had a play with your processed jpeg image in Lightroom, using curves, sharpen and noise reduction, and I couldn't really get any more detail out, though it looks a bit brighter (below). I like seeing what extreme processing will do :icon_biggrin:.

Niges rosette-1.jpg

Definitely you've got nebula there.

When I did mine I used 130 x 10s subs, bias and darks, but no flats (don't ask me why so short, it was early days!). I think I'm fortunate that my camera seems to have an inherently good red sensitivity. Mind you, I don't think I could replicate the result that ST gave again.

Ian

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Thank you @LeeRich and perhaps @Nigel G is best placed to comment on comparing those dimensions for the length of the shortened standard focuser.

Edit: Can't recall if you changed the mirror bolts.

Edited by happy-kat
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4 hours ago, LeeRich said:

I couldnt get prime focus when using my dads SLR hence adapting my webcam. But it was almost there so maybe the removal of this upper collar could work ?

Thanks for the info Lee. You raise an interesting point there, we are ( I am !) used to thinking about parfocal issues with eyepieces but I didnt extend the thought to different cameras.

4 hours ago, wxsatuser said:

I took the liberty of a quick ABE in PI just to see.

Remarkable what you have pulled out there !   What is ABE please  Edit, found it ! automatic background extraction.

Edited by SilverAstro
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1 hour ago, happy-kat said:

Edit: Can't recall if you changed the mirror bolts.

 I think the mirror bolts are radial not longitudinal/ (/ co-linear?), somewhere on the forum there was discussion about elongating the holes to allow movement along the tube ? Well into voiding warranty now ! :)

 

Edited by SilverAstro

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7 hours ago, LeeRich said:

Hi Peeps, sorry for late input.

I have attached a pic pf the focuser although the ruler is massively out of perspective so ignore it. I have measured it accurately and the measurements are correct.

The draw tube has an upper ring that unscrews, this collar is 13mm thick and with the aid of a T-mount to the inner thread i believe prime focus could be achieved.

I couldnt get prime focus when using my dads SLR hence adapting my webcam. But it was almost there so maybe the removal of this upper collar could work ?

I can get the thread measured of the inner 62mm length draw tube part if it helps.

Hope this helps guys.

Lee.

DSC_0080.JPG

I have just checked the distance between t ring and main tube. To get prime focus the distance needs to be 50mm

this is a picture of the t ring  in position. 

Nige.

20160507_171501.jpg

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3 hours ago, Nigel G said:

I have just checked the distance between t ring and main tube. To get prime focus the distance needs to be 50mm

this is a picture of the t ring  in position. 

Nige.

 

The main body of the GSO unit is 56mm before any of the collars are taken into consideration so i guess this particular focuser cant achieve prime focus on the 150 Discovery.

Thanks for the extra info Nige :D

Lee.

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Well, I've just spent 4 hours reprocessing my North America Nebula subs. I gave StarTools a try and although I actually managed to create an image I liked, the process still felt like doing surgery with a mallet! So I downloaded a trial copy of PixInsight to see what a real pro piece of software could do. First I had to retake my bias and dark frames so my camera moved to the fridge for a couple of hours. With bias, darks and flats at the ready, I went through the whole calibration, stacking and processing using PixInsight with only a few minor modifications made in Photoshop at the end.

BEFORE (44 x 45 seconds ISO 1600 with no calibration, stacked in DSS and processed in Photoshop)

large.572b7c3b4ce95_NGC7000NorthAmericaNebula43subs.jpg

AFTER (43 x 45 seconds ISO1600 with 28 bias, 85 darks and 40 flats, calibrated, stacked and processed in PixInsight and finished in Photoshop)

large.572f4b3757c8e_NGC7000NorthAmericaNebulaFinal.jpg

Very different images! (And I apologise that they are both low resolution. The final TIFF image for the second version weighed in at over 350Mb.)

I think the biggest differences in processing were around being able to remove the background and controlling the stretching.

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Hi Ken,

Thanks for posting the two versions of NGC 7000, you have been busy. Have you any plans for further imaging the object? I was tinkering with the idea of trying to image either this nebula or the cocoon Nebula tonight if it is clear and the wind drops here.

I was just posting Ken notifiaction of yours came in. 

I attach my coffee-paint scheme colour chart showing the light pollution to be contended with here. I have also been experimenting with omitting to use dark frames in DSS to see what happens. Please find below two images of M57 using the same x16 sixty second exposures but the first with x50 dark,bias and flat frames and the second image without the dark frames. There certainly seems less background stars and some of the red stars have stayed red and not turned white. Stacking in DSS and processing using StarTools.

First with darks-

M57SGL.jpg

The second without-

M57NoDarksSGL.jpg

Cheers,
Steve

Canon EOS 600D 5to80s.pdf

Edited by SteveNickolls
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I do plan on spending more time on the North America Nebula. I only imaged it the other night as a test. It was still very low in the sky. The forecast here suggests no clear nights for a week so I will probably have to wait. But it's going to be my project for a while now I know I can capture it. I'd probably be aiming for 200 more lights. 

Of your two images I do prefer the second even though it shows fewer stars. The background is less noisy and the colours look right. I also like that it gives M57 a little more space. 

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Hi Ken,

I can't imaging how good your NGC 7000 will be after x200 more light frames, very good luck with the project :-) Thanks too for showing the rest of us that it can be imaged. Yes it is quite low down as an object right now, from here it's ranging from 16 degrees at 10.30 PM  to 27 degrees around half past midnight.

Thanks too for your comment on the M57 images, it has me seriously wondering if I should bother taking dark frames as they do take up a lot of valuable imaging time of a night time. Decisions, decisions.

Hmm SGL is acting odd saving things today...

Cheers,
Steve

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Don't forget you can do your bias and darks during the day and they should be good for any future lights at that ISO and temperature. You can always cool the camera in the fridge or freezer to simulate night temperatures.

Flats can be done at dusk so long as you can see a bright star to focus on. Arcturus is perfect at the moment. 

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Hi Ken,

Thanks for this, I have tended to take the dark frames sometime during the imaging session to have the same temperature and the bias and flats the morning after. I agree though that taking the dark frames sometime before imaging is a good idea to make best use of the night time for taking light frames and will put it to use tonight if conditions improve-cheers :-) 

Steve

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The one advantage of British weather is that our night time temperatures are fairly stable. I find my Canon starts at around 26C as I use live view to align and focus, and cools to about 16C where it stays for the entire imaging session regardless of actual outside temperature. That makes it easy for me to build a dark library.

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Steve & Ken. Great images, nice work. I love the nebula's always my favourite. 

I had a go at NGC 7000 last night, a beautiful mild and clear night, went to bed as the morning chorus started 4.20 am.

I tried some longer exposures as the mount was on top form last night. The first image is 85 x 45s plus 5 x 90s @1600 iso, I added 2 x 90s darks to 14 x 45s , the flats didn't work again, 50 bias.  The second image is 85 x 45s , darks and bias. DSS and StarTools. The first image with the 5 x 90s seems to be slightly better to me.

I am pleased with these, while taking the subs I could only make out a fairly small amount of emissions but there's plenty in there. I'm sure more could come from these.

Nige.

PSX_20160508_180635.jpgPSX_20160508_181025.jpg

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Good going nige, well done. The cerise hue in the first image comes across brighter on my hudl but both are very good indeed. I fancy attempting this target but no way could I stay awake till the birds wake up. Good for those who can.

Good luck to all who image tonight.

Cheers,

Steve

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1 hour ago, Filroden said:

The one advantage of British weather is that our night time temperatures are fairly stable. I find my Canon starts at around 26C as I use live view to align and focus, and cools to about 16C where it stays for the entire imaging session regardless of actual outside temperature. That makes it easy for me to build a dark library.

So do you have dark frames arranged by temperature to use off the shelf Ken?

Cheers,

Steve

 

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20 minutes ago, Nigel G said:

Steve & Ken. Great images, nice work. I love the nebula's always my favourite. 

I had a go at NGC 7000 last night, a beautiful mild and clear night, went to bed as the morning chorus started 4.20 am.

I tried some longer exposures as the mount was on top form last night. The first image is 85 x 45s plus 5 x 90s @1600 iso, I added 2 x 90s darks to 14 x 45s , the flats didn't work again, 50 bias.  The second image is 85 x 45s , darks and bias. DSS and StarTools. The first image with the 5 x 90s seems to be slightly better to me.

I am pleased with these, while taking the subs I could only make out a fairly small amount of emissions but there's plenty in there. I'm sure more could come from these.

Nige.

PSX_20160508_180635.jpgPSX_20160508_181025.jpg

If I had taken an image as good as that I would print it and have it hung up! How good are your skies?

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An ideal time to remind viewers these images did not involve an EQ mount :-)

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Herzy, thanks ☺

I have quite polluted sky's but at 1 am the street light go out around here improving the sky's big time. London is 25 miles to the west of me, which is always visible in the western sky. The eastern sky is the darkest especially after 1am .

Nige

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