I have only just started down the path of imaging the night skies, and finally had an opportunity to try it out last Saturday night.
My skills are obviously very limited, and having just picked up my new Heq5 pro last week, and my ED80 a few weeks before that, my exposures are limited to ~10sec before stars start to lose their shape (my polar alignment skills suck frankly).
Anyway, my question is regarding whether the below image I took is about right for the equipment/exposure etc or below/above what you would expect @ 10 seconds. I was hoping for a little more personally, and their are heaps of issues with the pic i know.
its not bad you know kosh, may be a little out of focus too but i suspect you are on your way
really need to get better alignement obviously......... does your mount have a polar axis correction built int it?
pat
Yes, that's not bad at all for the given exposures. First thing to sort out will be autoguiding then it'll all fall in place from there on. But that would be the main thing to start with: longer exposures and attention to focus.
Good first try. Definitely out of focus, which is the first thing you need to learn how to perfect. There are several ways of doing that, depending
upon what kind of camera you are using. I noticed that there is no sign of green in your image, which an unmodified DSLR normally shows with
M42 in short exposures. What ISO did you use? So, in short, are you using aDSLR? does it have Live View? A bit more information, and I'm
sure there will be plenty of advice on this forum. The main thing that
I would stress is that astroimaging has a steep learning curve, so just
take your time, and your images will get better and better.
raymo
Not a bad start at all. Focus is the first thing, as others have said. But get hold of a freeware application called "Deep sky Stacker"- not hard to use - and stack 10 or 20 of these 10 second images. You will be amazed at the result.
Not a bad start at all. Focus is the first thing, as others have said. But get hold of a freeware application called "Deep sky Stacker"- not hard to use - and stack 10 or 20 of these 10 second images. You will be amazed at the result.
Thanks jon,
Actually thus image came out of DSS. Maybe my settings need looking
At?
Thanks everyone for your feedback,
The images are taken on a canon 450D @ 1600 ISO .
20 x light, 11 dark and bias. Ed80 on a Heq5 pro mount.
I used live view for focusing at 5x then at 10x and looked good at the time, wonder what happened.
All advice appreciated
Kosh...you really need to connect the camera to a laptop and use a program like APT or BYEOS (site is down atm) to control the camera and obtain fine focus. Fine focus using the rear LCD on the camera is well...not the best, 3rd rate at best! Not knocking what you have achieved in fact you have done well, but focusing on a laptop...lets say x 768 screen with Full Well half measure (FWHM) is a whole quantum better than using the rear LCD screen. I went thru trailing video screens (of various resolution) and such like but found at minimum a 1366 x 768 screen a whole lot better!
These astro camera control programs are a hoot! They make life so much easier that is not funny! In fact i wonder how I did it many many years back...I've forgotten, thankfully!
Practice your polar alignments or indeed for astrophotography try to learn drift alignment. There are a whole bunch of youtube videos out there and webs sites to learn this (see Drift Method Polar Alignment.pdf).
It just takes practice, once learned, you'll be an old hack in no time! Your mount and camera are top notch it's as said...a learning curve that cannot be done in 1 week...or even a year!
If all else in drift align fails...ask...plenty of users nearby to help!
Brendan
Edit:
forgot to say...I tried stretching you image in PS but had real trouble as the data was way down the left side of the histogram...meaning the image was way too short. As a rule of thumb, aim to image the histogram peaks to around 1/3 away from far left side of the histogram log. The far left is the darks, the far right is the lights! In otherwords not too dark (as these are) but not too much light as well! This is why we stack images instead of overexposing them. The light (image noise and light pollution) will wash out the image.
As the others have already pointed out, getting your polar alignment right is the first step, use an autoguider and make sure your focus is right and you could reasonably expect a single frame not much different to the one I took at Astrofest http://www.iceinspace.com.au/forum/s...&highlight=M42 that image is a single frame, Iso 800 5 minute exposure on an umodded Canon.
While that image is by no means decent, it's a good starting point, lesser exposure will bring out the blown highlights in the core, so a mix of exposures is the way to go.
Thanks Brendan,
I have heard of APT, Might give it a go. Regarding the histogram, I actually removed most of the darks to the left already as the sky was very bright on Sat night, maybe that's why it's over too much.
I know it's a long journey,I kind of hope it is actually. Just wanted feedback so I know whether I was on the right track. Definately will practise my polar alignment though, very hard with dim stars through the polar finder.
Phil I'd love an auto guider, plan to get one eventually, my wife will simply do away with me in my sleep if I spend any more on this at the moment !
The image you posted is still pretty nice.
Maybe someone has some "cost effective" suggestions for a guider that works?
Hi Kosh, mate what you have captured is about right for am unmodded camera. I took some images of M42 a couple of weeks ago. Generally with M42 you take atleast two sets of exposures, one set much shorter than the other so you can combine the two and have the detail in the nebula of the longer exposure and the detail of the core from the short exposure. Anyway the point to telling you all that was my short exposure was made up of 10x60sec and I didn't get much more than what you have shown.
Nice first image by the way. The learning curve is steep but a lot of fun and we are all here to help where we can. Keep them coming.
Kevin is spot on. So many newbies plunge into the deep end before
they can swim. IMHO Live View works well if used correctly. Find a bright star as near to your evening's target as possible, magnify it 10x , manually focus the star until it is as small as the one in the box at lower right of the screen. Then swing to your target, taking care to not disturb
the focus setting. Take a short exposure of your target and check the focus on the LCD screen. Check the focus is spot on by magnifying the
image on the LCD. I frequently use Live View with no problems.
Regarding your focus problem; Most lenses are so easy to turn when
in the manual setting that maybe the focus shifted during your
session.
Another cheap way to get good focus is a Bahtinov mask which I
use when imaging through my scope.
I suggest that you start modestly; get to know your gear well, so
everything is familiar in the dark. Start with single exposures around
10secs. Play with ISO settings. Don't bother with lights and biases.
Enable High ISO noise reduction. This will automatically take a
dark exposure after your exposure is completed. The camera also
does some bias work at the same time. As you can see from Acropolite's
image, you can get great images with single exposures. When you are happy with your results move on to manual guiding, multiple exposures,
darks, biases etc: whilst learning these skills practice polar aligning and
bone up on the stacking and processing software you will need.
hope this helped
raymo
Live on the edge.... She doesn't have to know.!!!!!
Starshoot autoguider and mini guidescope package is affordable.
Actually she is pretty good about it all, but looking at it, things like auto guiders aren't too expensive on their own, it's just I spend 2 grand in the last month on astro-photography equipment. Lucky I already had the camera. Besides, it will be good to get some old-school skills behind me before I go further.
Quote:
Originally Posted by cometcatcher
Your eye? Get a small guide scope + illuminated reticle eyepiece and guide manually. Saves mucking about with computers but hurts the neck.
Kevin, what is this "manually" of which you speak? This concept is unfamiliar to me
I think I will get the illuminated reticle eyepiece though . I need it for drift aligning right?
Quote:
Originally Posted by Rex
Hi Kosh, mate what you have captured is about right for am unmodded camera. I took some images of M42 a couple of weeks ago. Generally with M42 you take atleast two sets of exposures, one set much shorter than the other so you can combine the two and have the detail in the nebula of the longer exposure and the detail of the core from the short exposure. Anyway the point to telling you all that was my short exposure was made up of 10x60sec and I didn't get much more than what you have shown.
Nice first image by the way. The learning curve is steep but a lot of fun and we are all here to help where we can. Keep them coming.
Thanks for the encouragement Rex, I will post some more once the weather clears. It's almost like we moved Melbourne to the U.k. The last couple of months with all this cloud and rain...
I have the ISO noise reduction turned off. I might just have to turn it back on. Thanks.
You are right, I still have to familiarise myself with my equipment, no fun fumbling around in the dark. Sure the neighbours don't appreciate the colourful commentary I give under my breath either.
