dawson Posted September 4, 2012 Share Posted September 4, 2012 Hello all. How much astrophotography can I do without an equatorial mount? My Skywatcher 127 has a "Auto-Tracking Alt-Azimuth Mount". When Jupiter and me are up at the same time (I have too many early starts with work), how long an exposure will I get with my mount, and will be be any good? I've got a Canon 600D SLR. Thanks for any replies. James Link to comment Share on other sites More sharing options...
Brantuk Posted September 4, 2012 Share Posted September 4, 2012 Hi James - your mount should track well enough for short exposures of solar system objects (planets, moon, and sun) typically using a webcam as you can gather lots of frames very quickly then stack them in Registax. Unfortunately long exposure on deep sky objects is a none starter without an equatorial mount. After about 15-20 secs you'll get star trailing - your shutter needs to be open for several mins at a time to capture the faint light of dso's. For that you'd need to be accurately polar aligned and tracking in a single plane (RA). An alt/az mount tracks in two planes so the accuracy required to keep the image pixel perfect on a camera chip is practically impossible and as the Earth spins the stars will elongate. Even an equatorial mount needs guiding as well to reach the accuracy required. But solar sustem stuff will be fine - make sure your scope is adequately filtered before attempting imaging the sun. HTH Link to comment Share on other sites More sharing options...
dawson Posted September 4, 2012 Author Share Posted September 4, 2012 That is useful, thank you. But could I use my digital SLR to take a load of images of Jupiter to then stack? If so, how long would the exposures need to be and what sort of settings? I was hoping for a clear night tonight so I could try and play with the moon, but there a fair bit of high cloud at the minute, and as usual, I've got work in the morning so can't stay up too late. James Link to comment Share on other sites More sharing options...
Guest JohnC Posted September 4, 2012 Share Posted September 4, 2012 Hi James You are much better off with a webcam for the planets. John Link to comment Share on other sites More sharing options...
Brantuk Posted September 4, 2012 Share Posted September 4, 2012 Some dslr's have a "webcam" mode that enables a min or two of rapid shooting. Last time I got an acceptable shot using dslr i had iso 800 and speed was 200ths of a sec. But really it's the wrong tool for planets - you see the atmosphere makes planets appear to "wobble" or "shimmer". But for a split second here and there it gets dead calm and clear and a quick frame at that instant is the one you want. With a webcam you increase the chances of capturing that fleeting moment on film by rolling for about 5mins at a time collecting thousands of frames. Registax will then stack the frames and enable you to set how many percent of them you want to keep. It will stack only the best ones and throw the duds away. Google Damian Peach - he's the UK's foremost webcam imager of Jupiter and very famous. I think he uses one of the DMK webcam range (google that too). His website might offer a few tips. But like me - you'll have limited success with a dslr. Link to comment Share on other sites More sharing options...
Guest Ely Ellis Posted September 4, 2012 Share Posted September 4, 2012 Just looked at Damian Peach's website. Should make some interesting reading tonight. Cheers Kim Martin Link to comment Share on other sites More sharing options...
dawson Posted September 4, 2012 Author Share Posted September 4, 2012 OK, so it's largely a numbers game; these fancy webcams can take 60 frames per second, whereas my digital SLR can only take 4 per second or so? There isn't anything specific on his website about using webcams that I can find, but it seems he's made a DVD. Looks like I need a new laptop now then, as the current one only lasts about 5 minutes when it's not plugged into the mains! Thanks again for the help. James Link to comment Share on other sites More sharing options...
Brantuk Posted September 4, 2012 Share Posted September 4, 2012 James - I have the dvd if you'd like to borrow it. Also a good book to get is "Making Every Photon Count" by Steve Richards which gives a complete account of imaging in a very easy to follow and learn format. The DMK's are a tad expensive - but some extremely good results on planetary imaging have been obtained using the SPC900NC (or SPC880 flashed to emulate it). If you can find one that is. They're very rare at the moment being out of production and most snapped up by the astro community lol. PM me your address if you'd like to borrow the dvd and I'll send it to you. Just post it back when you're done with it. Link to comment Share on other sites More sharing options...
andyboy1970 Posted September 5, 2012 Share Posted September 5, 2012 (edited) Sorry to butt in, DSLR's give an image scale similar to a 25mm eyepiece whereas a webcam is similar to a 6mm eyepiece. I have captured Jupiter with my Canon 1000d and the resulting image is tiny. With regards to your mount - Field rotation is the big issue, alt/az mounts track in straight lines where Equatorial mounts track in arcs, so with an alt/az mount the subject seems to rotate. I have seen good results of deep sky subjects with exposures of up to 90 seconds. Give it a try and post the results, good or bad. Here is a link to a friends gallery, he uses the same mount you have. http://www.astrobin.com/users/smerral/ Edited September 5, 2012 by andyboy1970 Link to comment Share on other sites More sharing options...
Guest Steve Posted September 5, 2012 Share Posted September 5, 2012 Hi James, Take a look at Backyard EOS software. This connects to your camera and can use the Liveview feed of the 600D to record .avi movies..... I hope! (Going to try it at Kelling Heath and/or EMS start parties when I will be set up for a period with mains power so time to play around). Cheers Steve Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 From my very first attempt at taking astronomical photos with my telescope. Canon 600D plugged into Skywatcher 127; 1/20th second, ISO 1600. Lots of lessons been learnt already. Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 (edited) Things I've learnt tonight: It's a pain in the bum having to go somewhere and set everything up, and then take it all down at the end of the session. Roll on lottery win so I can buy somewhere remote and have a fixed observatory! Aligning the finder scope is a pain. Is there a way to limit how badly it gets misaligned between set ups? I think I need to take a plastic tray next time and just put things in that, rather than on the floor, as I was hunting for bits continually; I think I need one of those awful bum bags too as I just didn't have enough pockets! I also think I need a head lamp with a red filter on, as holding the torch in my mouth is a pain, as I need my mouth to hold other things! I am going to get a fold up chair tomorrow for sure. Does powering the telescope with a 12v battery rather than AA batteries mean the motor moves quicker? I sometimes wish I could override the motor and make adjustments by hand. And knowing if something is really in focus is dead difficult in the field. Is there a reliable way to check? Just some of my learning points / issues. James Edited September 9, 2012 by dawson Link to comment Share on other sites More sharing options...
andyboy1970 Posted September 9, 2012 Share Posted September 9, 2012 Nice first James. For the Moon put the ISO setting down to 100 and try shutter speeds from 1/160 and increase up to 1/500 sec and you'll find a nice one in there. You have nailed the most important thing which is the focus. Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 I have to confess that the camera settings weren't necessarily by design. I took loads at different settings (most of which were out of focus) but this one semi-worked. I'll have a go at your settings. Thanks. James Link to comment Share on other sites More sharing options...
Guest Fluke Posted September 9, 2012 Share Posted September 9, 2012 Great first effort James. Im a complete beginner on photography front so cant help you there, but with power I noticed a large speed improvement when I hooked my goto 127 mak up to a 12v 7ah Skywatcher power tank for the first time. Its seems faster still now that I use a 12v 38ah 'Baz' battery. Don't go buying a 12v battery of any sort until you've had a word with Martyn (Baz Senior) as he has been able to sort batteries out for many of us on here free of charge Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 Thanks Dan. What else do I need apart from one of these batteries? How does the battery connect to the motor as I've only got the lead whioch is connected to the AA battery pack. James Link to comment Share on other sites More sharing options...
Guest Fluke Posted September 9, 2012 Share Posted September 9, 2012 Im just off out until early evening but I'll post some photos of my setup to show you what you need tonight. Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 Dan, thanks. Baz has been in touch, and I've remembered that I've got one of these for blowing up my bike tyres and for keeping in the car in case of power emergencies: />http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_180794_langId_-1_categoryId_255206#tab1 I think I just need something to communicate from that to the motor of the telescope now. Baz has pointed me in the direction of Maplin's. James Link to comment Share on other sites More sharing options...
Teslar Posted September 9, 2012 Share Posted September 9, 2012 If its got a 12v accessory socket on it you can use it ok. You then need a 12v lead like this />https://www.altairastro.com/product.php?printable=Y&productid=16265 Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 Ok, thank you. What mount is my Skwatcher 127 on? Would this fit? It's got 5m cable which is a bonus too (maybe). />http://www.ebay.co.uk/itm/Skywatcher-5m-power-supply-cable-12V-/280709302783?pt=UK_Photography_Telescopes&hash=item415b9409ff James Link to comment Share on other sites More sharing options...
Teslar Posted September 9, 2012 Share Posted September 9, 2012 Yep all skywatcher mounts use the same power connector 2.1mm centre positive Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 That's great, thank you. Now I'm just bot sure how long to get the lead. I guess at least with 5m I could use the car as the power source in an emergency. James Link to comment Share on other sites More sharing options...
dawson Posted September 9, 2012 Author Share Posted September 9, 2012 I've got various cables with a cigerette lighter type fitting, and I've got a connection which fits the mount (from another universal kit (which only supplies 15V+)), could I cut the socket off the end of an old cable and solder the one which fits on? How important is polarity? James Link to comment Share on other sites More sharing options...
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