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Paramount

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Posts posted by Paramount


  1. Hi Guys

    Thanks for the positive comments, and thanks for the comments about the website David, I have tried to make it entertaining, interesting and educational so that perhaps anybody looking at it might develop an interest into astronomy and imaging and have a go, forums like myastrospace are a real plus in that they get like minded people sharing tips etc.

    Best wishes

    Gordon

    :smile:


  2. Hi

    It was one of those nights again last night, trying to decide whether to try some imaging or not. There was patchy cloud dotted over the sky with a few clear patches and occasionally some thicker patches drifting in occasionally, I have seen this before where I live and sometimes it is worth giving it a go even if only to salvage a few frames.

    I decided to give Van den Berg 142 (Elephants trunk nebula) in Cepheus a go as it had just risen high enough over my neighbours tree. I managed to get 15x10 minute unguided subframes with the TMB 115/Starlight Xpress H36 on my Paramount ME. Unfortunately 6 of the frames had to be junked because of cloud damage and the last two frames because "good light stopped play".

    I did a sum combine and 0.8 gamma stretch in Maxim DL and then transferred to CS2 where I used 3 iterations of curves and local contrast enhancement using Noel's tools.

    I have enclosed the widefield version and also a cropped closeup. I was having a further play with Noel's tools and added false colour, these can be seen on my website

    http://www.imagingtheheavens.co.uk

    in the image gallery under nebulae

    Considering the clouds and short imaging time I am quite pleased with the result

    Thanks for looking

    Regards

    Gordon:smile:

    elephant-trunkHa.jpg

    elephant-trunkHacrop.jpg


  3. Hi Tim

    Thanks for the encouraging comments and you are right with your comments about your own emission line image, it isn't easy, there are a few more things to take into account that aren't so evident with RGB such as combatting the dominance of Ha, the necessity to use good flat field frames. A good source of help is a guy called Richard Crisp of narrowband imaging fame, he runs a Yahoo group on emission line imaging and is very helpful if you want to check him out and he has his own site with good info as well, good luck with your processing, look forward to seeing the results

    Best wishes

    Gordon


  4. Hi

    Trying to make the most of the clear nights, no clouds last night so was able to do

    6x10 min Ha

    8x10 min OIII

    8x10 min SII

    all unguided with the TMB 115 on the Paramount and the Starlight Xpress H36

    Processed SII (red) Ha (green) and OIII (blue)

    Less noisy than my earlier efforts but still want to try for more longer subframes, Very pleased with the field flattener and filter wheel

    Thanks for looking

    Regards

    Gordon

    :smile:

    north-america-nebula.jpg


  5. Hi Ray

    Thanks for the comments, the filter wheel is the FLI-CFW-1-5 which carries up to 5 x 2" filters and the filters are by Astronomik in Germany. In reply to rogerg, I agree that this has been over processed and I am reworking it using the same data but going about it a different way, I will post as soon as I have finished it. I did use dark frames but I only use the autodark facility in Maxim DL that takes one dark frame and automatically subtracts this from each image, this is mainly due to time constraints which is also why I have never used flat fields.

    Regards

    Gordon

    :smile:


  6. Pelican nebula 1st attempt at colour emission line imaging

    Hi

    I would like to submit my image of the Pelican nebula to get you started. I took it last night in less than favourable conditions, ie intermittent cloud threatening the area where I was imaging and occasionally moving right in front of it.

    I used my TMB 115 f7 APO with matching field flattener, FLI filter wheel and Starlight Xpress H36 camera. This was on my Paramount ME, I had planned to do 70 minutes for each channel in 10 minute subframes but the last two subframes had to be junked because at 3.30am it became too light to image.

    Exposures were all unguided

    Ha - 7x10 minutes

    OIII - 6x10 minutes

    SII - 6x10 minutes

    Simple autodark subtraction in Maxim DL was used but no other calibration.

    I combined the subframes for each channel using sum in Maxim DL and the resulting masterframes were colour combined in Maxim DL in the order of SII (red), Ha (green) and OIII (blue) - hubble palette. I tweaked the ratio of the colours until I got the look I wanted. This was then converted to TIFF with an auto stretch and transferred to Photoshop for processing. 3 iterations of curves were used as well as local area contrast enhancement with Noel's tools. A gradient was reduced with Gradient Xterminator and colours were adjusted

    Regards

    Gordon

    :smile:

    pelicanreprocesssmall.jpg


  7. Hi all

    After an abysmal May as far as weather is concerned I have finally got my filter wheel up and running and as the sky was clear last night (it was up till mn) I thought I'd chance my luck and have a go at the Pelican nebula. After I got everything aligned I was ready to begin just before 12mn but as the camera was taking its dark frame for auto dark subtraction patchy clouds started rolling in from the southwest and this was the pattern for much of the rest of the evening. I decided to stick with it though and managed to shoot 7x10 minute unguided each of Ha, OIII and SII (the last one of the OIII and SII had to be junked because daylight stopped play). The was a period of about an hour when there was no cloud at all but the rest of the time patchy clooud came very close to cygnus and on a few occasions covered where I was imaging (thankfully only for a few seconds each time)

    I combined the 6x10 minute SII(red), 7x10 minute Ha (green) and 6x10 minute OIII (blue) Hubble palette style. Onle 3 small iterations of curves were used as well local area contrast in Noels tools. No levels were used. Considering the rush and the threatening cloud I am well chuffed. I have also enclosed a cropped close up of the Pelicans "neck" to show the chimneys a bit better.

    Thanks for looking

    Clear skies

    Gordon

    :smile:

    Pelican-nebula-hubble-palle.jpg

    Pelican-closeup.jpg


  8. Hi Ray

    Thanks for the comments, the ultra widefield shots were really intended to try out the field flattener and see how it would work with the TMB and the H36 camera. All my previous shots with the H36 have had to be seriously cropped due to vignetting but thanks to the flattener and the right width adapters no cropping was used in the M51 or the M106 widefield. When I first combined the subframes for both the M51 and M106 shots the light pollution was so bad in the images that on both of them the central part of the images were both a very light grey and at first I was so disappointed with the light pollution gradient that I wasn't going to process them further or post them. The rest of the image I was delighted with ie, sharpness, tracking, round stars, no vignetting etc. Then I remember someone mentioning on another forum about a plugin for Photoshop called Gradient Xterminator by Russell Croman http://www.rc-astro.com

    This cost about £29, so I thought I had nothing to lose so I downloaded it and gave it a try and after about 30 minutes of trial and error (I didn't follow any instructions) I got rid of virtually all of the gradient (there are tutorials on how to use it elsewhere on the web). This program is available as a trial download. So there you have it Gradient Xterminator, a very useful plugin for Photoshop that does what it says on the tin, it exterminates gradients. I would certainly recommend this to any of the members here if you want to suggest it for a "Must have section"

    On another note, although I did the ultra widefields as a test, I have to agree with you that although they don't necessarily show the fine detail in DSO's that you see in close ups they really do portray a sense of scale and make you appreciate that although some of these objects are massive ie hundreds and thousands of light years across, in the big scheme of things they are actually tiny and very isolated. I will be doing colour, both LRGB and emission line and some close ups with the C14 but I do have to admit that I do rather like the monochrome, Ha and widefield.

    Kind regards and clear skies

    Gordon

    :smile:


  9. Hi all

    I wasn't really sure about posting this one but here goes, it was taken after the M51 ultra widefield that I took last Wednesday just before it got light. I had just got the right extension tube from APM so I could try out the matched field flattener for my TMB and Starlight Xpress H36, these are the first shots that I have done without having to crop the image due to severe vignetting. As I am waiting for custom adapters to put my filter wheel in this setup these images are completely unfiltered so they suffered somewhat from light pollution which I managed to get rid of most of it with gradient xterminator. As I haven't got into flat frames yet there are some dust bunnies which are evident depending on your monitor settings, they are not that evident on mine. I only managed 30x2 minutes unguided on this subject before it got too light so effectively this image was taken between 3am and 4am. Anyway enough of the excuses. While there are a lot of faults in the image I was pleased to capture some of the other faint fuzzies in the neighbourhood in particular NGC 4217 to the left of M106 which came out even better on the cropped image (no extra processing done on this, just cropped and enlarged). For the rest of the image no curves were used, just a bit on levels, some contrast enhancement and major work with Gradient Xterminator.

    Thanks for looking and again my apologies for the dust bunnies

    Kind regards and many clear nights

    Gordon

    :smile:

    M106.jpg

    M106crop.jpg


  10. Hello everybody

    Thanks for all the nice comments, the nights imaging was more about testing new equipment than getting a decent image as this was the first outing of the dedicated field flattener that I got for the TMB which had a slight problem when I first received it in that I couldn't get focus as there wasn't enough back focus but that was soon rectified with 3.5" starlight extension tube. Thanks to this wide throughput of light compared to using 2" extension tubes and nosepieces there is no vignetting problem which means I can now utilise the full field of the H36 camera which is great as all my previous images with this camera have had significant cropping used to try and eliminate the vignetting. The only problem with the field flattener is that you can't put a filter wheel with it as this would alter the distance between the flattener and the camera and effect its functioning but thanks to Precise Parts in America I have got the necessary adapters on the way to put the filter wheel between the camera and flattener without altering the critical flattener to camera distance so I should be producing some colour and full emission line images soon. When I first started to process this image the light pollution gradient appeared so bad especially in the middle part of the picture, that I wasn't going to bother posting it but I purchased Russell Cromans Gradient Xterminator and had a go and hey presto after a bit of tinkering I managed to get rid of the gradient. There is some evidence of dust bunnies which can be made out depending on your monitor settings but I couldn't see them on mine. As was mentioned by Tim I am really pleased at the level of detail that has come out with the cropped version without any pixelation being visible. And don't worry Ray there are a lot of DSO's like the Tarantula, Eta Carina, Omega centauri to name but a few that I would dearly love to image with my setup that you have down under

    Thanks again and clear skies to all

    Best wishes

    Gordon

    :wink:


  11. Hi all

    Finally managed to get a clear night after over a month of bad weather and work. This is my first outing using the matched field flattener for my TMB so the widefield image has not been cropped. There was bad light pollution and plenty of sky glow where I lived so I have used Gradient Xterminator to try and get rid of the gradient that plagued most of the image. Only a slight levels adjustment was used, no curves. One iteration of local contrast enhancement using Noels tools was used as well. The image is made up of 60x2 minutes unguided. No filters were used as I am waiting delivery of adapters to connect my filter wheel into this set up.

    Higher quality images are available on my website www.imagingtheheavens.co.uk

    Thanks for looking

    Kind regards and clear night to all

    Gordon

    :smile:

    M51.jpg

    M51crop.jpg


  12. Hi Guys

    Thanks for all the comments

    Ray, I think you are out of luck being able to see M101 as it is visible from where I live all year round, it's a shame but I have the same problem with some of the beauties that you get down under.

    Patrick, thanks for arrowing all the fuzzies that you could see, I had a go at zooming right in using Photoshop and I think I could see 20 altogether but some were very faint.

    I will probably try guiding at some point, I think it is a case of having such limited imaging time with work, unpredictable weather, setting up and so forth that I try and spend as much time on the imaging and you are right about the mount, it is incredible in every department and I haven't even begun to use all of its capabilities.

    Best wishes and clear skies

    Gordon

    :smile:


  13. Nice image of one of my favourite galaxies Gordon. I wish it was visible in the south. As I see it, the faint fuzzies are from right to left: NGC 5474, 5477 and 5473. The edge on galaxy is NGC 5422 I think.

    Cheers

    Steve

    Hi Steve

    Thanks for the comments and the help with naming the fuzzies, everybody has been very helpful here. I share your sentiments about the visibility of some of the DSO's, there are a lot like eta carinae, omega cenauri, etc. etc. that I can never see from where I live and that is where I think one the great things that these forums do is to bring like minded enthusiasts from around the globe together to share images that it is impossible for some to see and image. Congrats on your image of the week by the way.

    All the best

    Gordon

    :smile:


  14. Hi

    I couldn't make up my mind whether or not to go out and try imaging last night because the weather was so bad during the day, ie snow in the afternoon and rain in the evening but it started to clear about 9pm and I eventually decided to give it a go at about 10pm. I thought I'd have a go at a galaxy for a change so I tried M101 as it was fairly high in the sky and away from most of the effects of light pollution. I set the computer to do 20x8 minute subframes unguided (one of these days I will be trying the autoguider), I didn't use longer than 8 minutes as when I tried a longer test exposure the core appeared a bit burnt out. Everything went fine until the dreaded meridian flip on the 19th subframe. Although the sky was clear ie no clouds the seeing wasn't too brilliant. There are a couple of other fuzzies which I am not sure about, one towards the top left and one towards the bottom right, I haven't had a look as to what they are yet, but any suggestions would be most welcome. A better quality image is on my website http://www.imagingtheheavens.co.uk

    Taken with TMB 115 f7, no flattener (yet)

    Paramount ME

    Starlight Xpress SXVF H36 with broadband light pollution filter

    Exposure 18x8 minutes unguided

    Thanks for looking

    Regards

    Gordon:smile:

    M101.jpg


  15. a refractor, to me does great for planetry viewing and imaging and is also ok on deep sky. the reflector is opposite. it is strictly deep sky but can also be ok for planetry.. I suppose, in that case, hybrids can have the best of both worlds.

    apart from that, the main thing that counts is appeture. the bigger the scope, the better. But larger scopes can have problems. cost, wieght and transportability. Thats why i personally prefer the reflector, I have a 12" reflector. cost per inch of appeture is alot cheaper, it is alot lighter and easily carried, but ok.. it still takes up room in the car but hey. 2 out of 3 is fine by me..

    In a year or so, I will be buying a 16" lightbridge for around $3500 and also adding argo narvis to it, about another $1000-$1500. That'll be around $5000 worth of automated 16" lightgathering power. in the case of a refractor, 16" would be, at a guess, well over twice as much, both in weight and cost. At the end of the day, people seem to prefer spending $2500-$5000 for mediochre 8" views at the eye piece. still, 8" or 10" refractors have everything the budding atsro-photographer needs. It's not too expensive, doesnt take up too much room, not too heavy and is almost ready to go straight out of the box.

    Hi

    You are right about a 16" refractor being at least twice as much but if you are looking at an APO think more in the region of 20 to 40 times as much and if you think I am joking check out the prices for large APO's from the likes of Pentax, TMB, Takahashin etc, also an 8 or 10" refractor is very big and heavy. I helped deliver a 7.5" TMB last year, it took 2 of us to lift the box and one person at a push could just about put it on a mount. With APO's as aperture goes up price, size and weight goes up considerably, to give an example of cost I think the 7.5" TMB I helped deliver cost £11500, a 15" TMB would be in the region of £115000 approx

    It makes a 16" reflector seem an absolute bargain

    Regards

    Gordon


  16. refractor or reflector

    Hi Mike

    I don't think there is a clear cut answer to this question, but here goes to some pointers.

    For deep sky imaging an apochromatic refractor preferably with a short focal ratio is considered one of the best choices as it will give high quality images and the short focal ratio will give shorter exposure times. An APO will be fine for planetary imaging but you will need a much longer focal length and hence longer focal ratio in order to get the magnification, this will result in longer exposure times which is not a problem for the moon and planets as they are extremely bright in relative terms and will need very short exposure times anyway. Newtonians are also good choices for deep sky work as they generally have short focal ratios.

    With imaging it is important to remember that the size of the aperture will have no bearing on the exposure time needed as this is governed by the f ratio, if you want to put this to the test get a 50mm and a 400mm camera lens both with a fastest f number of f4 and put them both on a dslr and set the f number to f8 on both and you will find that the shutter speed will be exactly the same for a given shot. This means that for imaging especially DSO's the f ratio is the most important factor.

    There are so many different types of telescope including refractors, reflectors and the hybrids in between and for each one there are different types, for example with reflectors there are newtonians, cassegrains, RC's, etc., for refractors there are achromats, semi APO's, APO's, doublets, triplets and so on. This is one of the reasons why a lot of people have more than one scope in their armoury, usually something like an SCT for planetary work and the smaller DSO's and an APO for larger DSO's or any combination of the above.

    You then have the added problem of choice of ccd cameras and matching them properly to your chosen scope, I'd better stop here because things get even more complicated here with arcsec/pixel ratio, quantum efficiency, non-anti blooming v's anti blooming, OSC v's monochrome. The choice of how to put a perfectly matched system together is an absolute minefield which is what makes forums such as this so good in that you can ask advice from people who have been through this difficult selection process.

    Hope this helps

    Regards

    Gordon

    :smile:

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