Recently Browsing 0 members
No registered users viewing this page.
I currently am on holiday in my father's hometown, a small island near rhodes called symi.Symj, is a pretty small town,with only about 2000 residents.That means that the light pollution levels must be low. Acknowledging that, i called my friends, grabbed my 10x50 bins(that i got for 20€ from Turkey),and went on my way to find a dark site.About after 20 mins of walking (from the city),i stumbled upon a beach, it was dark, so i went in.There i decided to lay on a sunbed that was there.After looking up(not being dark adapted, my friends just kept turning their flashlights on for some reason), i saw the haze of the milky way stretching from Cassiopeia to cygnus and beyond!I was amazed as i ve never seen the milky way before and smudged it off as clouds until i confirmed it was the milky way from an app! The weird part was that at just straight overhead, was the port ,which had many lights, and as a result the sky appeared half bright and half dark. I turned over at Sagittarius and headed over the lagoon nebula. Brilliant! 3-4 stars in a line surrounded by bright nebulosity.(while still being in the haze!) Afterwards i headed to cygnus,it was a real light show! I saw the milky way layering on top of Cygnus while catching a glimpse of m23 and yet again, failing to see NGC7000 . Then, with the corner of my eye, i detected something moving, then turned over to Cassiopeia to see a shooting stsr!(it was my first time seeing one!!!) Was very brief, yet enjoyable. Right afterwards i turned over at the Perseus double cluster.Magnificent! Appeared as 2 small balls of light , almost connected yo eachother. Finally, i realised that finally, the target i was seeking to observe all year long, M31 was into the area with the light pollution! What a shame! While also being low on the Horizon, I couldnt see it with the naked eye. I observed it with ny binoculars for 10 minutes or so . The core was resolved nicely with some hints of outer nebulosity. Overall a great night and now, i wished i had my 8" dob with me....
(Sorry for any granmar mistakes, im currently typing this at 2 am xD)
I have just joined and have been looking around, and putting in various searches to find the answer to my question(s).
I have already found some valuable information, but i can't find a specific answer to a question i have relating to exposure times.
I have shot the milky way several times before, from a tripod and a wide angle lens. I am aware of and understand the "500 rule" and that worked fine for me at first when i was shooting with my Canon 6D Mark II. When i moved over to the Sony A7III i noticed significant trailing using the same rule and that led me to the NPF rule (Via the photopills app incase people dot know).
I am heading back to Tenerife once again in about 6 weeks time and want to buy a star tracker so i can get some really detailed images.
I have done a fair bit of research and in principle, the whole thing doesn't seem to be too daunting or difficult.
I have purchased the Polar Scope Align Pro app so i can align Polaris as accurately as possible, i will practise putting the unit together and familiarising myself with the different parts etc, but it is the exposure times that i do not understand.
My best glass is the Carl Ziess 50mm F/1.4 Planar, the 18mm F/2.8 Batis, the Sigma 35mm F/1.4 Art & the IRIX 15mm F/2.4 Blackstone.
I currently do not own, nor have i ever used a tracker, and I cannot find any information relating to which aperture, ISO and Shutter length any of these focal lengths should or could be shot at.
Is there anything similar to the 500 rule or NPF rule that relates to using a tracker with varied focal lengths? or is it just a case of stepping the lens down for sharpness and then trial and error?
Thanks in advance,
Second attempt at astrophotography with my canon 1300D untracked (first was orion ). Shot under dark skies of himachal pradesh (India).
Stacking done in DSS and processing in Gimp.
Any suggestions would be appreciated. especially regarding the trees at the bottom.
Total exposure time - 20*20 seconds
Shot with - Canon EOS 1300D (untracked) (unmodded)
Flats and Biased frames included
We had a few hours of clear skies here on Saturday night, so I set about getting some O-III for the Western Veil, after I had collected the Ha last month. Thankfully, the moon wasn't around, so even though I didn't get that many subs (only 10) at least they were of good quality.
I actually fell asleep during the capture, and woke up to a 'Sequence Aborted' message in SGP and the sight of PHD2 going mad due to thick clouds. Quickly ran outside and thankfully there was no rain about (phew!). I got 11 subs in total, but the last one was totally unusable due to the clouds. The 10th one was affected too, but still looked useable to me, given that I know from experience that APP's 'Quality' stacking mode would know to give it less of a weighting, so I kept it.
So this is 15 * 1200s of Ha and 10 * 1200s of OIII (8 Hrs 20 mins in total).
Taken with the usual gear: Nikon D5300 (modded); HEQ5-Pro and a SW 80ED.
Calibrated with Flats, Bias, and a Bad Pixel Map. APP used for stacking and gradient reduction. Everything else done in PS (including running Carboni's 'Synthesize Green Channel' action).
After now having processed both the Eastern & Western Veils, I have to say I have found them to be among the hardest targets to process that I've done so far (although it's still early days for me yet, think I'm still under 15 DSO's and counting). I'm not sure if it's down to the sheer number of stars, or the very faint nebulosity that seems to be everywhere, but I've found the background to be especially difficult on these ones. Getting the Ha and OIII nicely balanced before combining probably has something to do with it. I also tend to do gradient reduction (which seems to affect the OIII a lot more than Ha) on the individual stacks before I combine them, so I wonder if I'd be better just leaving it to later in the process? (which I had to do again anyway, as there was still a noticeable red gradient visible later in the workflow).
Something to note, I did go quite heavy on the star reduction. More so than I normally would. I found it wasn't until I upped it significantly, that the nebulosity really started to take centre stage. I like the impact it has made to the image overall, but it made me feel a little dirty at the same time, lol (if that makes any sense).
Also, this isn't actually the finished version just yet. I have a bit more work to do on the background and stars (which need their colour toned down in places - probably shouldn't have ran Carboni's 'Increase Star Colour', in hindsight I don't think it needed it). I was literally falling asleep at the monitor last night while attempting to finish it off, and in the end had to admit defeat. So hopefully I can get around to it later tonight.
Then the next thing will be the big mosaic of both Eastern & Western Veils. I'm both looking forward to, and dreading it, in equal measures ?
As always C&C warmly welcomed!