Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Space Ranger

Members
  • Posts

    174
  • Joined

  • Last visited

  • Days Won

    1

Everything posted by Space Ranger

  1. The skies are pretty dark at this location - typically bottle 2 & ~21.8 SQM reading. This amounts to an amazing number of stars being visible when clouds permit. As a consequence the minor image processing done was to brighten the foreground and darken the sky a bit This was to reduce the effect of all the faint stars and thus make the hexagon more obvious.
  2. The attached image shows the bright winter stars that form the Winter Hexagon. It was captured from a dark location in Caithness in northern Scotland on a particularly chilly night (-12 deg C), but the view of the star filled sky made it well worth braving the cold. This single long exposure was taken with a soft focus filter over the camera lens in the style of astrophotographer Akira Fuji. I like how the filter makes the brighter stars more prominent, helping the constellation shapes & star colours become more distinct. The image is a single shot captured using a static tripod, DSLR and wide angle lens (astromodded Canon 600D, 16mm FL, f3.5, ISO6400, 30s). Processing was done in Adobe Lightroom 6 & Paintshop Pro. Hope you like it :)
  3. Thank you Richard. That was a really fabulous presentation. Also being a chemist, this has been a topic of interest to me for years. Last year I was lucky enough to take a trip to see a chemical elements exhibit in the Ulster Museum in Belfast - https://www.nmni.com/whats-on/elements-exhibition. It was fascinating, and if in the area it's well worth a visit. The person who put it all together is Dr Mike Simms - one of the people who has been researching the location of the asteroid impact site in northern Scotland 1.2 billion years ago - https://blog.geolsoc.org.uk/2019/06/10/scotlands-earth-shattering-secret-how-to-find-a-meteorite-impact-crater/. Here's a few weblinks I found of particular interest whilst reading up on the topic in the past few years. Maybe others will find them of interest too... https://www.americanscientist.org/article/a-chemical-history-of-the-universe ; http://www.astronomy.ohio-state.edu/~jaj/nucleo/index.html https://www.youtube.com/channel/UC3cyRVDoePNf_rLQlwKpdeg/videos https://elements.wlonk.com/ElementsTable.htm
  4. Thank you both. Glad you like the end result. Just in case anyone is wondering why only 29 exposures were taken it was due to clouds interfering. I would normally look to have star trails covering a 20-50 min period (not easy at times in the north of Scotland)
  5. This image shows star trails over the largest of the two Neolithic Grey Cairns of Camster. It was produced by taking 29 exposures (Canon 760D, 30s, ISO6400, f/3.5, 16mm FL equivalent) in sequence, which were processed using StarStax to produce the star trails, with final image adjustments carried out in Adobe Lightroom 6 . This is a very dark location, so a dimmed LED light panel was located about 30m down the hillside to gently illuminate the stones of the cairn. I waited many months for the free time and right conditions to capture this image composition. I felt that the short passage of time shown by the star trails, would provide an interesting contrast with the 5000 years that had passed since these chambered cairns were originally built and used by humans. The imaging was timed so that some faint aurora above the horizon provided colourful backlighting to the scene.
  6. Thanks for your very clear and helpful advice Adam J. As I suspected I have a bit of thinking to do before the piggy bank gets raided. I found a useful reference table for these cameras here - https://agenaastro.com/media/documents/ZWO_Camera_Specifications_v4.0.pdf (with more discussion here - https://agenaastro.com/zwo-astronomy-cameras-buyers-guide.html) It looks like they would both be a good choice for what I'm hoping to used them for (ie pretty much everything except narrowband and detailed planetary imaging). But as you've pointed out they both have their individual strengths depending on the optical kit they are connected to. As there is not a big difference in price I think I'm leaning towards the 294mc pro based on the following...…. I quite enjoy widefield imaging, but tend to make the individual images into multi-pane mosaics, so not much pixel peeping of the final image takes place. I've been happy with the resolution afforded with DSLR/lens combination thus far - the noise has been the bigger issue. As the image scale with 294mc will be similar to that of the 600Da and 760D I use, I suppose its use for this could still be acceptable and will provide a step forward on the noise front. My main imaging is through the Skywatcher 80ED, and the 294mc looks to be the ideal match for it on my budget. Looks like the lesser pixels might not fill up my portable hard drive as quickly either. I enjoy imaging the moon and seeing what interesting features I can pick out. I know this is probably where the 294mc lags a bit behind the 183mc, but I don't suppose you can have everything. I normally image the Moon from my garden (which is surrounded by heat emitting houses), so the increased image scale achievable with the 183mc might not be that beneficial a lot of the time anyway. And when the seeing is good I suppose I can jus pop in the good quality barlow lens I have? The above mentioned website guide says the 183mc is good for EEA too, just not quite as good as the 294mc. So probably not much difference between them for that method of use. I wonder if anyone can comment / advise on the following: - anyone know if these cameras can be hooked up to a microscope or to a really wide angle lens to "video" aurora. - what spec of laptop would be needed to operate the camera - I have an old-ish i7 based one, but the battery life is poor. I also have an Asus with a m3 intel processor, SSD storage and a battery that lasts for ages - would it be up to the job? Gordon
  7. I've spent a few years carrying out unguided astroimaging with a DSLRs and have gradually reached the stage where I can get results I'm very happy with. Although I very much like the uncomplicated portable nature of the DSLR setup (especially when hooked up to a Star Adventurer mount), I think the new cooled OSC CMOS cameras may provide significantly better results for me taking into account that I want to keep things "simple", the amount of time I tend to have available is limited, and my normal astroimaging arrangements. I'm therefore looking at potentially purchasing a new camera and would welcome the advice of the very helpful and knowledgeable people who use this forum. The astroimaging I do is varied. I know it isn't possible to have a camera that will be ideal for all equipment set-ups and all celestial targets, but I'd like to choose a camera that would be capable of producing decent results for as much of the imaging I like to do as possible ie - widefield imaging to produce sky mosaics (mainly using 50mm and 105mm lenses) - imaging of nebulae, star clusters, larger galaxies, bright comets etc using a Skywatcher 80 ED refractor (I seem to be able to easily get 60-120sec subs without trailing through this scope on a EQ-AZ5GT mount, depending on how much time I spend on polar alignment, and how near the celestial equator I'm imaging) - imaging of the moon (and very occasionally planets) using a Skywatcher 80 ED refractor and a Celestron 6"SCT (I'm not too worried about planetary imaging at the moment as at 58.5N they are not ideally placed for me just now - too low and normally hidden by surrounding houses) I'd also use it to give "real time on screen" views of celestial objects at local astronomy events. I set up the mount/scope from scratch each session, either in the back garden or often at locations a 30 min drive away where there is less light pollution (SQM readings >21.5). The Scottish weather (cloud / wind) and other commitments tend to limit me to 1-3 hours observing / imaging per night, so being able to gather useable data quickly is important to me. At this stage my image processing skils are relatively basic, so I'm after a camera that will allow me to "see" and image lots of different objects without any illusion that I'll be able to produce prize winning results. I'm not interested in guiding or narrowband imaging at this time (or probably anytime soon). I've used a ZWO 120MC camera before for lunar, solar and planetary imaging and was quite impressed by it, so based on this and reviews I've read I'd be happy to buy a ZWO camera. I'm willing to spend £1k (or thereabouts). Based on a bit of reasearch, including reading lots of forum posts (some of which were way over my head!), I'm thinking the ZWO 183C MC Pro and ZWO 294MC Pro may suit my needs, but am not ruling out other options for now. I'd welcome advice that would aid my decision making.
  8. "....unique advantage of seeing the clouds 24 hours per day" - doesn't sound like much of an advantage to a stargazer North is very near the centre of the image, with west on the left hand edge and east on the right edge. Six wide angle shots were taken, stitched and cropped a little to give the final result.
  9. The early hours of 19th June produced the first sighting of NLCs in 2018 for me, and what a fab display it was......
  10. I too have a mobile / non-permanent set-up and unpredictable weather - hence my preference for a DSLR thus far. I may be tempted sometime by the new CMOS cameras though as they can produce good results with unguided short exposures, so I could get usable data within my normal sort of imaging session of a couple of hours. The use for lunar imaging appeals too. I've trawled through some images I've taken to look for 600Da and 760D images I've taken of the same object on the same night to compare side by side. I've attached single unedited images from each, just as they came out of the camera. The 760D image is on the right in both cases. Settings were ISO 3200, and 60 seconds. I normally use ISO 1600 or ISO 800 when imaging through the scope, so not sure why the higher ISO was used in this case. I think it shows that there is very little discernible difference in noise performance between the two at these settings (note that at ISO 6400 I definitely feel the 760D has an edge). Not surprisingly the 600Da picks up the H-alpha emissions far better. So if the DSLR will only be taking photos through a telescope, for stacking and processing, the quality of the end image taken with a 600D or 760D won't be much different. So probably doesn't warrant the extra cost you'll pay for the newer one. If like me you'd use your DSLR for other types of photography, then the newer, higher spec and more expensive camera might be worth it. I'm afraid I can't give a comparison with the 450D that you're obviously familiar with. I have to add though that I find the live view capability on a flip screen that is touch sensitive (as the 760D has) brilliant and very convenient to use for night time imaging. HTH
  11. I agree, the Samyang lenses are very good. I have 2 friends that use the Samyang 14mm f/2.8 - their night pics (using a Canon 750D and 5DMkII) look great - I wouldn't say the Sigma 10-20mm I have is any better optically. I bought my lens for use in the daytime and at night, so wanted the autofocus capability the Samyang doesn't have. Also with a cropped sensor (as my 760D camera has), the Samyang has an equivalent focal length of 22mm, as opposed to 16mm with the Sigma. This can make quite a difference when shooting landscapes/nightscapes/aurora - hence why I decided the Sigma was the lens best fitting my needs (& budget), even though it wasn't quite as fast a lens. The Sigma lens has served me well - couple of examples attached.
  12. My astroimaging sessions tend to be in winter at <5degC so that probably helps my shots wrt noise. I haven't tried out autoguiding, so tend to be 2min or less exposure length when shooting through a scope. I have taken a few 5 min exposures with a wide angle lens and Star Adventurer mount without any obvious image artifacts though. I currently have an astromodded 600D and also a 760D. The modded 600D offers a huge improvement in sensitivity to the red end of the visible light spectrum. I don't see a big performance difference between the 2 cameras for astroimaging through a telescope in any other aspects, although I tend to find the noise in the 760D images a wee bit less and easier to manage during the rudimentary image processing I am capable of doing. So as I think Adam J is saying, paying for a new 750D might not get you much better results than a similar camera that is a good bit cheaper. I didn't select/buy the 760D primarily for imaging through a telescope, although it does produce decent results. I bought it for the type of photography I do most - daytime photography and "nightscapes". I find it produces cleaner single shot nightscapes at high ISO than the 600D & a 650D I previously had use of (couple of nightscape examples attached). So for the sort of photos I take, the likes of the 750D/760D was good balance between what I hoped to achieve and what I had available to spend. At some point I might venture into the dedicated astronomy camera territory, but I like the portability and hassle free(?) nature of astroimaging with a DSLR for the moment. HTH
  13. Although faster lenses are definitely beneficial for aurora and nightscapes imaging I have been using a Sigma 10-20mm f/3.5 lens for a few years now and it produces decent results . It can be bought for a little over £300 and gives a wider field of view than the 14mm Samyang will on a cropped sensor camera like the 100D.
  14. I have a Canon 760D which has the same sensor as the 750D. I use it most for daytime photography and widefield shots of the night sky. I've also managed to get some telescope shots through equipment not dissimilar to yours. It is a good camera for all of that. I haven't used the 450D but having had experience of a 600D and 650D I would imagine that compared to the 450D, the 750D would offer reduced noise and articulated touch sensitive screen as well as the higher sensor resolution. The sensitivity to H-alpha isn't great though, so if you're main interest is in imaging emission nebula, you'll find far better options out there. I've attached an image of M42 I obtained with approx. 30 min total exposure time (most 1 min subs), to give an idea of what can be produced by someone with basic image processing skills. HTH Later added point of clarification - on checking I've since realised the above image was produced from captures using an astromodded Canon 600D, so maybe not an ideal example to provide considering the original post was about a 750D
  15. Thanks scarp15 - it is a fantastic location in the daytime as well as on a clear night.
  16. The Milky Way and a hint of aurora showing in the starry skies over the largest expanse of blanket bog in Europe (the Flow Country of Caithness & Sutherland). Single two minute exposure (f3.5; 16mm FL; ISO 1600) captured using an astro modded Canon 600D on a Star Adventurer mount........... A fabulous scenic dark location - 21.7 on a Unihedron light meter. This was the third night in a row I got to enjoy views of the aurora
  17. Shoplifting Aurora - Sure you can come and stay anytime gkec - plenty of sky and aurora for us all to share the view. Thanks Roger. With your location Roger I'm sure you appreciate that unlike paintings on the night the view was changing quite rapidly. It's good to capture a snapshot of the view as a keepsake though.
  18. Yeah - that's what I thought. Maybe a raptor hovering above the moor? It certainly seemed alive on the night - there was lots of movement. I should maybe have said that you might have to view the images full size to see the stars of the Plough through the light pollution
  19. On the evening of the 17th March in the north of Scotland the dancing lights of the aurora filled the sky and put on a mesmerising show (despite the misty conditions). Attached are a few of many wide angle shots of the aurora I obtained that evening. If you look closely at the images you can see the Plough - which will give a sense of scale to these wide angle shots. The images were taken near Strathy on the north coast of Scotland using an astro modded Canon 600D and 10-22mm Sigma wide angle lens (at 10mmFL). It's been a busy month for me, so it has taken a while to get a few pics processed. As a result these are not providing breaking news - I hope you enjoy seeing them nonetheless.
  20. Thanks happy-kat. I should probably have said that the reference to ET was in relation to the cluster on the left side of the image. It is NGC457, which is also known as Caldwell 13, the ET cluster or the Owl cluster.
  21. Thanks BigMakStutov. Got some clear skies last night (albeit a little hazy), so had to give it another try...... I'm much happier with this one.
  22. Couldn't resist having a go at catching this..... Comet Lovejoy near to the ET (or Owl) cluster. Unfortunately in my rush to get an few image before the moon lit up the sky I didn't get the focus as good as I would have liked, and the breezy conditions meant my setup was getting buffeted a bit. I might have to have another go at this target later this week if the weather permits. [The image is a single 60s exposure (Canon 650D; f/5.6; ISO1600; 400mm equiv FL) on a Star Adventurer mount.]
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.