Forum Replies Created
-
Posts
-
Posted by Marlyn Smith at 11:19 on 2011 May 16
Hi Stephen,Nice image. Don’t forget to send your best images into the Solar Section for archiving.
Posted by Marlyn Smith at 11:10 on 2011 May 16
Above image by Martin Mobberley of AR1203 imaged at 0850 UT 20110501
Above image by Monty Leventhal showing a pair of large converging prominences imaged at 2230UT 20110511 (Australia)
Above image by Martin Mobberley of a prominence hearth imaged at 0814 UT 20110504
Above image by Dave Tyler showing white light and H-alpha images of AR1203 imaged at 0814 UT 20110502
A tenuous strand of plasma imaged by Dave Tyler at 0958 UT 20110501Posted by Marlyn Smith at 10:59 on 2011 May 16
Here a some recent images by Solar Section members. The below image is an H-alpha image taken by Pete Lawrence 20110508
Image below by Peter Woolliams 20110512
Image below by Martin Mobberley of AR1199 and filaments 20110501 at 0845UT
Posted by M C Butcher at 10:19 on 2011 May 16
Andrea,Many thanks for your response. I was planning to use a 20mm f/2.8 lens. Unfortunately I think your second paragraph indicates that there is something about this that I don’t fully understand.I appreciate that to get the Analemma all images must be precisely aligned and taken at exactly the same time of day. With a film camera the only way to do this is to clamp the camera to the same spot, with the same alignment for each exposure. However, with a digital camera, provided there is an identifiable object that does not move (eg a house) in the field of view can the alignment of the images not be conducted in the computer using the photo processing software? After all I can routinely take photos of terrestial scenes which I then merge together to give a panoramic view. It was this technique that I assumed made taking Analemma photographs with a digital camera much easier than with film.Or have I totally misunderstood what modern technology can do for me?Many thanks.Martin
Posted by Jeremy at 21:35 on 2011 May 14
Hello Nick,I have the same CCD camera. I control the camera and capture images using AstroArt. I use the same package for image calibration (flat-fielding and subtracting darks) and I process in Photoshop. For variable star photometry I use AIP4WIN – the BAA VSS has a spreadsheet for handling the AIP4WIN output files, making it easy to extract the magnitude in a format that can be uploaded to the VSS and AAVSO databases.I haven’t used the other two packages to which you refer, although I understand Maxim DL is excellent.Go well!Jeremy
Posted by R S Winter at 13:40 on 2011 May 14
Hi NickI don’t think the Starlight software is much good, although the cameras are OK. Any of the three you mention should be OK, I use Maxim which I really like.RegardsBob Winter.
Posted by Andrea Tasselli at 18:09 on 2011 May 12
Hi Martin,First off analemmas as best created with cameralens as the field of view required is normally far too large for most scopes. Depending on the lens choice this will severely restricted the size of the sun disc on the image. If you won’t use filters (such as baader’s astrosolar) than you should aim at taking the sun’s shots fairly low on the horizon and use the shortest exposures @ f/22. ISO could be around 200. Using filters you’d probably need to open up the lens quite a bit and adjust exposure as required. I’d keep ISO as low/high as required. Just experiment a bit and you’ll find the right combo.Now for the second question. You’d need either to clamp down the camera or the camera tripod (assuming you can move the camera in and out of the tripod without disturbing the aim) for a whole year or you need to have a reference in the field of view that won’t move for a year and a way to exactly match the position of the reference object before taking the shot (this is quite difficult to do unless you use an alt-azimuth mount with slow motion controls). This can be done regardless of whether you shooting without filter or with filters as you’d just need to remove the filter, align the camera and put back the filter before taking the shot in the later case. The way to do is the analemma is to know or estimate the exact position of the sun at the winter solstice and at the summer solstice at the same UT at your location. This will set the requirement of the maximum focal length you can use (and hence the size of the sun’s disc on the sensor) and how you can emplace the whole set-up with regards to the local features you’d need either to include for reference purposes or for the landscape shot to be overlapped against the analemma.This is just to get started. The nitty-gritty details can be discussed later.Hope it helpsAndrea T.
Posted by David Mottershead at 19:58 on 2011 May 10
Hello PaulLooking at the image of the moon that you took the other night using your D40 I’d suggest that you’ve answered your own question. Great image!
Posted by Graham Relf at 16:29 on 2011 May 10
I just happen to have seen a photo of Pluto taken with a Nikon D40: hereGenerally I agree with those who say just try it and see what you can get.
Posted by Roy Hughes at 11:28 on 2011 May 10
Paul,re CanonsIf you’ve got a stock of old Nikon lenses that you want to use there are a number of cheap Nikon/Canon adapters available on Ebay (some of questionable repute!).Only manual of course but should be OK for astronomy.Roy
Posted by Callum Potter at 10:12 on 2011 May 10
Hi Paul,I would always advocate trying it out for yourself, rather than relying on perceived wisdom…Especially if you have the gear and its not going to cost you.Having said that, my understanding was that the Nikons do some processing in-camera even in raw formats, which may not be desirable…I use an ancient Canon 300D – if buying new i’d either plump for the latest cheap Canon (1100D), or if flush a 60D or 5D mkII.Callum
Posted by Paul A Brierley at 06:50 on 2011 May 10
Thanks David,Roy.I’m going to have ago with this camera and see what it is capable off. But I might decided to buy a 1000D (body only) to use for astro-imaging instead. I’ve seen some excellent work produced by those canon camera’s.And. For the price. They are also, considerably cheaper than a dedicated CCD camera with a similar sized sensor. All I need is a reasonably clear sky, with know Moon interference. Incidentally I used my D40 at the week-end with my William Optics, and imaged a nice Waxing Crescent Moon. You can see the result on my blog…
Posted by Roy Hughes at 12:29 on 2011 May 08
Paul,Google: Nikon D40 Astronomyproduced several old <2009 links, mainly with missing pics (except one of moon) but with several hints.It looks like, provided you’ve got an IR remote release (priced from 99p to £6), you should be able to use it without too much trouble on manual "B" exposure. Just strap it to a driven scope mount, turn off the flash(!) and give it a try. Anything after that should be the same as any other camera.Roy
Posted by David Mottershead at 12:09 on 2011 May 08
Hello PaulI don’t own, and haven’t used a Nikon D40, but up until last month I did own a Nikon D50, which is very similar to the D40, originally sharing the same 6 megapixel sensor among other components, although a 10.2 megapixel sensor was available later in production in the D40x. I have now purchased the Nikon D5000.Given the commonality of several key components between the D40 and D50, I would suggest that, based on my use of the D50, that the D40 will produce good astrophotographical results. Have a look at my website in the gallery section where there are a couple of examples of astro images that I did with the D50, (I actually have quite a few more, but just haven’t had time to put them on my site yet!!), http://www.dmottershead.co.uk I’m not the worlds greatest photographer and am certain those more capable in these matters would produce far better results than I have with this camera!!The main thing to bear in mind here is that the D40 is a discontinued model, (although as with the D50, it can represent an excellent seconhand buy), and more importantly doesn’t have ‘live view’ mode – that is, you can’t look at what you are imaging using the LCD screen, which can really assist when focusing the camera.For what it’s worth, my opinion is that the Nikons, (D40, D50 etc) were very compentent and usable entry level DSLRs when introduced in 2006 (in the case of the D40), that can produce some really good astrophotograpical results. I hope this is of some help to you.
Posted by Graham Relf at 12:11 on 2011 May 07
More new charts just added, for May and June: see http://britastro.org/computing/handbooks_charts.html
Posted by Robin Flegg at 08:33 on 2011 May 07
Trevor,I can’t find a method to contact you directly on this forum; so I hope you read this message.Please can you contact me on rfhome[at]hotmail.co.uk ?I would be eternally grateful if you would!I only get to use a PC at weekends, so my reply might not be very swift.Kind Regards…Robin
Posted by Trevor Adams at 19:18 on 2011 May 01
Hi RobinI have every cd produced of the sky at night mags would be more than happy to helplet me know what and where to send .(no cost)Trevor
Posted by Gordon MacLeod at 20:19 on 2011 Apr 28
Thanks again Roy.Registax support are helping resolve it so hopefully I’ll get a solution.Thanks agaain and happy observing!Gordon
Posted by Roy Hughes at 15:19 on 2011 Apr 28
Sorry about that. I’ve used VirtualDub for manipulating .AVI and .MPG files for years and it normally will read a working file OK. Don’t give up though there are some others that might work. You’ve probably got some DVD or CD authoring software that came with the PC, worth a try. I’ve a sneaky suspicion that there have been some changes in the .AVI spec. in recent years that may not have reached the now elderly VirtualDub or at least not without a plug-in.Roy
Posted by Gordon MacLeod at 22:42 on 2011 Apr 27
Thanks Roy.I had a rake through the internet and also tried downloading a programme called virtualdub and loading it onto that but it didn’t work either.It was a 30 second video (avi) using the Celestron software, with 10 frames per second, i.e 300 frames about 1GB in size. It is a frequent problem, some work, some don’t, but very frustrating nevertheless, particularly when you think you have got a good image!(Always seems to be the best ones that don’t work!)Not to worry, but I appreciate your response.Kind Regards,Gordon
