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Home Forums Observing and Imaging Group My week in dark skies, Brecon Beacon.

This topic contains 61 replies, has 7 voices, and was last updated by  Astrograph 2 years, 10 months ago.

Viewing 15 posts - 1 through 15 (of 62 total)
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  • #8274

    Tej
    Participant
    Topics: 36
    Replies: 582

    Sorry for my absence on here, I have much catching up to do with recent days posts.

     

    I do have good reason though ūüôā ¬†I just came back from a wonderful week of dark skies at a star party in Brecon Beacon, Wales. ¬†We gotta have our own, fingers crossed for the current potential candidate!

     

    So what have I achieved at this seldom opportunity of dark skies? ¬† Well, I’ll tell you I worked hard to make the most of it. ¬†Some of you might recall, I own an HEQ5 Pro mount for over a year but never used it, a crime that Mike is intent on punishing me by confiscating it off me and charging me a penalty fine of 50 quid!

     

    I studied the polar alignment procedure and practiced it a lot ensuring I get it precise as possible.  I know what to do with those strange setting rings now!

     

    So after a year of carrying the damn thing all over the place like an idiot and not using it, I finally get to put it through its paces.  And man, what a great mount.  It slewed to all sorts of objects showing them dead centre in the eyepiece as I enjoyed a tour of the cosmos.

     

    But the real test was in imaging.  My greatest desire since I began this hobby was to image a galaxy, and in particular M31 Andromeda.

     

    That dream is now fulfilled and here it is:

    M31 Andromeda Galaxy with M32 and M110

    22 X 60 sec exposures = 22mins total integration time

    10 Dark frames

    30 Bias frames (excessive I know)

    no flats

    ISO 6400

    Camera: Canon 650D

    Mount: HEQ5 Pro Synscan

    Telescope:  Skywatcher Equinox 80 APO refractor

    no filters.

     

     

    Andromeda was the only object I spent time on taking many images at different settings and stacking.  But the greatest sensation I had when taking these andromeda images was that I could actually see it with the naked eye.

     

    I missed an opportunity to capture a sundog, I had no battery in my camera!  The first time I ever saw one. Oh well.

     

    I took many images but these are my personal highlights.  Apart from the Sun (video stack), they are all just one frame exposures, no stacking.  But still, I am absolutely pleased with my first series of deep space captures using an equatorial.

     

    As for the Sun Pic, I reverted back to my DSLR because I cannot stand putting up with the large dust bunnies on the QHY5L-II sensor, its driving me mad.

     

    Earthshine crescent moon at Astrocamp 2014

     

    Orion Nebula

     

    Solar prominences and plages at Astrocamp 2014

     

    Pleiades at astrocamp 2014

    #8275

    Andy Sawers
    Moderator
    Topics: 113
    Replies: 588

    Wow!

    #8276

    Mike Meynell
    Moderator
    Topics: 119
    Replies: 746

    Tej,

    These are superb images… the Andromeda Galaxy image is breathtaking. Really well done, and just goes what you can do when you use all of your equipment ūüėČ I’d like to place this in the gallery, if that’s OK with you.

    The one frame exposures are also superb… would have been nice to see a stack of the Pleiades, to bring out the nebulosity, but it still looks great nonetheless.

    I doubt that the skies in Sheppey will be anywhere near as dark as Brecon Beacons, but at least it’s a lot closer to home! Keep up the good work Tej… you’re improving every time I see one of your images.

    #8302

    Andy Sawers
    Moderator
    Topics: 113
    Replies: 588

    10 Dark frames
    30 Bias frames (excessive I know)
    no flats

    I cant wait to find out what that all means on my digital astrophotography course! ūüėČ

    Technical virtuosity aside, Tej, it must have been really thrilling to capture such images!

    #8304

    Brian Blake
    Participant
    Topics: 187
    Replies: 409

    Tej

    Great shots. You should think about entering astrophotographer of the year next year.

    #8311

    Tej
    Participant
    Topics: 36
    Replies: 582

    I found out today¬†that Flikr Explore featured my Andromeda image! ¬†How the hell that happened, I have no idea but I am certainly proud, albeit numbed by its inclusion. ¬†Brian told me not to be too negative to myself so I am not…but still, Mike might need to have a look at Flikr’s formula, there may be there¬†maybe a variable misplaced somewhere ūüôā ¬†I mean there are¬†so many more beautiful andromedas out there with colour in them, perhaps they consider good first attempts.

     

    Thanks all for the kind comments and encouragement, everyone, I’ll use as fuel for me to work hard and improve in delivering more cosmic images…although I say work hard, its an absolute joy capturing these ancient photons!

     

    Mike, by all means use it for the gallery, its always an honour.

     

    Andy, you will definitely learn about Darks, Bias and flat frames on your course!  As a heads up, they are called calibration frames.  Basically used to mask out temperature/sensor noise, dust bunnies on lens and sensor, vignetting (the gradient distortions around the edges caused by imperfections on the optics).   These frames are stacked with the light frames (your actual images) in a stacking software that uses clever algorithms to subtract the afore mentioned imperfections.

     

    I find Darks and Bias frames are the easiest to do. ¬†For Darks you simply take a few snaps with the lens cover on using the same settings, exposure, orientations and focus on the camera that you use for the actual images (called the light frames). ¬†For Bias frames, its exactly the same but at the lowest exposure times your camera is capable of, ie the lowest F-stop. ¬†My one has the lowest of 1/4000. ¬† The flats are the trickiest¬†and in fact I have only done it once! ¬†This requires a uniform light on the the object lens. ¬†Can be a light box or pointing at a uniformly lit part of the sky or having a white t shirt…there are different methods. ¬†I decided I want to use a laptop screen (a separate laptop, so yeah, I now carry two laptops, one for taking the images, while using the other as a light box, lol). ¬† Flats take more effort but are worthwhile doing if lens optics have a lot of vignetting.

     

    Anyway, thats all a heads up for you, hope you enjoying your course so far!

     

    • This reply was modified 2 years, 11 months ago by  Tej.
    #8313

    Brian Blake
    Participant
    Topics: 187
    Replies: 409

    Tej maybe they think it is a good image. You are being negative, I am impressed by what you are achieving and your posts can only help others in their endeavours.

    #8314

    Mike Meynell
    Moderator
    Topics: 119
    Replies: 746

    I found out today that Flikr Explore featured my Andromeda image!  How the hell that happened, I have no idea

    I’ve given up trying to work out how images make it to Explore on Flickr. Several of my images have made it, and not necessarily the ones I consider my best by any means.

    One think I know is that, if you make it onto Explore, your images are more likely to make it onto Explore again. It seems to be based on comments and favourites, and if your image is not in many groups, it helps.

    All totally pointless, of course. The key thing is that you’ve enjoyed making the image, and that the people you respect enjoy looking at it.

    #8315

    Tej
    Participant
    Topics: 36
    Replies: 582

    Oh I went negative again, sorry Brian, although it was an opportunity to crack a joke for Mike to sort out Flikr’s formula ūüėČ ¬†I promise I wont be negative and yes, what is even more important is that we relay our knowledge and findings to¬†others as all of you do and that I actually enjoy doing that the most.

     

     

    #8316

    Mike Meynell
    Moderator
    Topics: 119
    Replies: 746

    Hi Tej,

    Just had a quick look at these pictures again on Flickr. Could I suggest that you invest in a field flattener for your Equinox 80?

    The stars in the centre of the field for Andromeda, Orion and the Pleiades are lovely and round, but at the edge of the field they are egg-shaped. A field flattener will help you to get rid of this distortion.

    #8319

    Tej
    Participant
    Topics: 36
    Replies: 582

    Absolutely, Mike.  Advice duly taken. That will be my next purchase.  I do see that the stars elongate at the edges, I wonder if I had taken flats, would that have helped?  I know flats averages the gradients caused by vignetting but not sure about the elongation of the stars at the edges.

     

    Anyway acknowledged, best to get it right at capture than in post processing, anyway.  So I will get this one, what do you think?

    http://www.firstlightoptics.com/reducersflatteners/skywatcher-field-flattener.html

     

    There is also a combine 0.85x focal reducer/field flattener here.  If the field flattener performs as well as the one above then I might go for this one but question is, I wonder if this combined piece sacrifice performance on the field flattening and does 0.85x really make much difference to exposures? for 100 quid extra is that a significant reduction.  might have to do some research there.

    http://www.firstlightoptics.com/reducersflatteners/skywatcher-85x-reducer-flattener-for-ed80.html

     

    Do you  have any recommendations or shall I just go for one of these?

     

     

     

    • This reply was modified 2 years, 11 months ago by  Tej.
    #8321

    Tej
    Participant
    Topics: 36
    Replies: 582

    Doh, I didnt notice you already hyperlinked the flattener, lol. ¬†I think I will just buy that one¬†and thanks for finding¬†the right one for my scope¬†ūüôā

    • This reply was modified 2 years, 11 months ago by  Tej.
    #8324

    Mike Meynell
    Moderator
    Topics: 119
    Replies: 746

    I wonder if I had taken flats, would that have helped

    No, it wouldn’t I’m afraid. Flats only correct for dust, vignetting and uneven brightness. What you are seeing is an optical distortion, because the telescope is designed for visual use and therefore produces an image which is in focus on the curved surface at the back of your eye. The camera sensor is flat, so you need to adjust for this when taking astro-photos through a telescope.

    I’d wouldn’t bother with the reducer – you can fit the whole of M31 on to your sensor now, so I think your field is wide enough, and your exposure times aren’t too long. The flattener that I linked to is so cheap, that you can’t go far wrong in my opinion. Most of the reviews of this flattener are very good.

    #8348

    Tej
    Participant
    Topics: 36
    Replies: 582

    Thanks Mike, flattener now on order!

     

    Just want to add one final picture from my wales trip. ¬†Its of the same Earthshine crescent moon I showed earlier but that one¬†looked quite bland and I don’t like the framing. ¬†I cropped it more and gave it a monochromatic gradient which I think makes it more lovely for me but not sure if it does from anyone else perspective?

     

    Crescent moon Earthshine in Breacon Beacons

    #8351

    Mike Meynell
    Moderator
    Topics: 119
    Replies: 746

    I cropped it more and gave it a monochromatic gradient

    Works for me, Tej. Gives the image a beautiful ethereal quality. The light gradient in the sky draws your eye to the tree and then over to a perfectly exposed Earth-shine Moon.

    Well done!

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