carastro Posted September 13, 2013 Share Posted September 13, 2013 I have been using a DSLR for about 3 years and am not into the technical side of things, I just do what works.When I started I was advised to do 800iso and 5min subs and this has stood me well (except shorter subs for bright cores and combine). However I was plagued by noise and in my experience I didn't find taking darks made a lot of difference. I then read about some-one who lowered the iso but took longer subs.So tried imaging at 400iso and took 10 minute subs instead of 5mins and I have to say it made quite a difference to the noise.I only tried once imaging at 1600 iso and the noise was horrible in comparison to 800iso.I would suggest you try different iso and see what works.Carole Link to comment Share on other sites More sharing options...
Pete Presland Posted September 13, 2013 Share Posted September 13, 2013 Well, I tried imaging with my 450D at f/11.8 with ISO800 for 300s...Not an awful lot you can see on the pic... M31 nor M101.I shall try ISO1600 with 400 or 500s. I'm interested. Haven't gotten any startrails yet, since I'm guiding with PHP.I just need a better scope...i would expect at 300 secs on M31 to see quite a lot of detail at ISO800 Link to comment Share on other sites More sharing options...
Russe Posted September 13, 2013 Share Posted September 13, 2013 i would expect at 300 secs on M31 to see quite a lot of detail at ISO800At an FL of 1500mm??? Link to comment Share on other sites More sharing options...
Pete Presland Posted September 13, 2013 Share Posted September 13, 2013 At an FL of 1500mm???that does seem a bit long, the mak is not the best for DSO's (a bit slow) but you should still be getting something Link to comment Share on other sites More sharing options...
Russe Posted September 13, 2013 Share Posted September 13, 2013 that does seem a bit long, the mak is not the best for DSO's (a bit slow) but you should still be getting somethingYeah I'm getting smth, but not an awful lot. LP is pretty bad too.I'm gonna give it another go tomorrow night and see what a Mak needs to show DSO's.The camera is fine - with just a simple 50mm lens I'm getting results, but the Mak is so awfully slow... Didn't think it was gonna be THIS bad though... Link to comment Share on other sites More sharing options...
Russe Posted September 13, 2013 Share Posted September 13, 2013 Just testing the camera again just on a tripod with 800/1600 ISO at different exposures.Works.I'll try to find a jpg of a 300s exposure to show what I mean... Link to comment Share on other sites More sharing options...
Russe Posted September 13, 2013 Share Posted September 13, 2013 This shows a 300s exposure of M101, a 180s exposure of M31 and a 300s exposure of M31.All done with a 450D on a (I know...) 127 Mak. Link to comment Share on other sites More sharing options...
Russe Posted September 13, 2013 Share Posted September 13, 2013 All done at ISO800.Pretty bad LP with the wrong scope.Fairly good guiding though.Tomorrow I wanna try ISO1600 and then go for as long as I possibly can.Please don't be cloudy!!!! Link to comment Share on other sites More sharing options...
Pete Presland Posted September 14, 2013 Share Posted September 14, 2013 M101 is quite a large faint object with low surface brightness magnitude so not the easiest of targets. your last M31 has some decent detail, i think i can make out some of the dust lanes. imagine what 20 x 300 sec subs would like after stacking and processing, have you got a light pollution filter? Link to comment Share on other sites More sharing options...
lensman57 Posted September 14, 2013 Share Posted September 14, 2013 Is this right? Unity gain (i.e. where 1 photon gives 1 ADU) for the Canon 1000D is somewhere between ISO 800 and 1600.NigelMHi Nigel,I think for 1000d it is about ISO 1000.A.G Link to comment Share on other sites More sharing options...
Russe Posted September 15, 2013 Share Posted September 15, 2013 M101 is quite a large faint object with low surface brightness magnitude so not the easiest of targets. your last M31 has some decent detail, i think i can make out some of the dust lanes. imagine what 20 x 300 sec subs would like after stacking and processing, have you got a light pollution filter?Thanks for your kind words...Note to self - get a light pollution filter - any you could recommend?I'm just now getting 20x600s of M33 at 1600 ISO. Will post my result... Still not too great methinks, but the guiding seems good. Could go longer, but the LP is too bad.Overall, I'd hope with a 130pds I could enter a different territory in imaging terms. Link to comment Share on other sites More sharing options...
CC_Japan Posted September 15, 2013 Share Posted September 15, 2013 A newer full-frame camera like the A99, D600/800 or 5D Mark III should produce great results at ISO 1600 and may be even above. On my APSC-sized Sony A77 I find ISO 1600 already pretty bad, but then again Sony's 24MP APSC sensor is notorious for being comparatively noisy. Unfortunately, great ISO performance usually comes at the cost and weight of a full-frame camera. Link to comment Share on other sites More sharing options...
Pete Presland Posted September 15, 2013 Share Posted September 15, 2013 i use the canon eos clip light pollution filter http://www.rothervalleyoptics.co.uk/astronomik-cls-light-pollution-eos-clip-filter_d3555.html you will probably be able to pick one up 2nd hand, also you can not use them with your standard lens if it is one of the EF-S series.i would certainly be using the 130pds for DSO'S imaging ahead of the MAK127 Link to comment Share on other sites More sharing options...
RikM Posted September 15, 2013 Share Posted September 15, 2013 I would love to see some images from a 130PDS. I reckon it should be cracking scope for deep-sky-on-a-budget AP with a DSLR. If it had been on the market when I bought my 150P, I would have had the 130 PDS instead.I use a SkyWatcher LPR filter on the end of my coma corrector and it works for me, but the EOS clip-in filter would be more useful, as would also allow for widefield stuff with lenses. Link to comment Share on other sites More sharing options...
Daniel-K Posted September 15, 2013 Share Posted September 15, 2013 i constantly image on iso800 i like to keep that sensor cool to stop the noise. i have a bit of a OCD Link to comment Share on other sites More sharing options...
Daniel-K Posted September 15, 2013 Share Posted September 15, 2013 I would love to see some images from a 130PDS. I reckon it should be cracking scope for deep-sky-on-a-budget AP with a DSLR. If it had been on the market when I bought my 150P, I would have had the 130 PDS instead.I use a SkyWatcher LPR filter on the end of my coma corrector and it works for me, but the EOS clip-in filter would be more useful, as would also allow for widefield stuff with lenses.STARFOX is using a 130pds or AP he reckons its ace Link to comment Share on other sites More sharing options...
Russe Posted October 2, 2013 Share Posted October 2, 2013 To get the discussion back on track - I've read Craig Stark's paper on DSLR LX capabilities.He would definitely say, NOT to image at ISO 1600. 400 seemed to be ideal. Have a look: http://www.stark-labs.com/craig/resources/Articles-&-Reviews/CanonLinearity.pdf Link to comment Share on other sites More sharing options...
dph1nm Posted October 2, 2013 Share Posted October 2, 2013 He would definitely say, NOT to image at ISO 1600.If you follow the Cloudy Nights discussion of this article you will find that he somewhat retracts this and concedes that ISO1600 should be better at low light levels (i.e. when you are read noise limited).NigelM Link to comment Share on other sites More sharing options...
Russe Posted October 2, 2013 Share Posted October 2, 2013 If you follow the Cloudy Nights discussion of this article you will find that he somewhat retracts this and concedes that ISO1600 should be better at low light levels (i.e. when you are read noise limited).NigelMInteresting! Would you happen to have a link for that? Link to comment Share on other sites More sharing options...
Russe Posted October 2, 2013 Share Posted October 2, 2013 http://www.cloudynights.com/ubbthreads/showflat.php/Number/5299843This is 2012 and he seems to favour 800. Link to comment Share on other sites More sharing options...
Russe Posted October 3, 2013 Share Posted October 3, 2013 Here's another discussion on that matter:http://www.cloudynights.com/ubbthreads/showflat.php/Number/5623767 Link to comment Share on other sites More sharing options...
Pete Presland Posted October 4, 2013 Share Posted October 4, 2013 i think 800 ticks most of the boxes, the rest is down to experimenting with whatever works in any given conditions. Link to comment Share on other sites More sharing options...
alan potts Posted October 4, 2013 Share Posted October 4, 2013 Well I have just read through this thread and even though I have a modded Canon 40D and a Mummut OSC and I have not used them. Stupid, maybe. I am half decent with a camera and have won a good few things down thw years, I know what I am doing with any camera and a Mountain scene or whatever. Astro photography seems like a black art with dark forces at play, with advice on ISO from 400-3200, that 3 full stops difference, I would have thought that all but the very best DSLR's would be very noisy at 3200, or don't that matter a well?Alan Link to comment Share on other sites More sharing options...
RikM Posted October 4, 2013 Share Posted October 4, 2013 You are not wrong Alan, AP really is the dark side It is quite a difficult concept to grasp, that you don't need to use a very high ISO. With basic daytime photography, typically you increase the ISO setting to get a brighter image, but it simply doesn't need to be that way for AP because of the way you process the images. Even with daylight photography, good photographers would generally prefer to use a sturdy tripod and increase the exposure time rather than up the ISO. Link to comment Share on other sites More sharing options...
alan potts Posted October 5, 2013 Share Posted October 5, 2013 Rik,Spot on, most of my real work was done with positive film where even plus .3 -.5 of a stop was a big step, I always used a tripod and I guess all AP photographer do the same. Though with some of the lenses these days it is difficult to mess up, at a price of course.I must get out and try my kit some time, I bought it intending to have a go and it's just sitting in thier boxes doing nothing. The Mummut OSC was a waste of money as far as I can see, well for me at least, I thought it was more video than a camera. I was pleased with what it took in 10-20 seconds though when I did try it the one time, but the whole experience didn't tick the right boxes for me, prefer the eyepieces. I will tell you the other thing that puts me off the amount of air traffic of all kinds that goes through the FOV, of the larger kind, last week week three aircraft, all while looking at the same object on different nights.Alan. Link to comment Share on other sites More sharing options...
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