Imaging crisis.

[simon84]

I've recently started imaging with my newly aquired EOS 1000D, but I dont think I'm happy with it.

I bought it for a couple of reasons, one was price, the other was the dual use of it as I am a mad keen photographer anyway.

What I didnt really take into account was the overly large fov that a dslr will produce. I knew it was big but now I've been out there with it I'm just not happy.

I want to spend my time imaging DSO's and getting some nice full frame views of them with plenty of detail. Obviously I'm not going to get this with the 1000D as M51 looks like just two larger stars amongst a larger field of stars, an exageration I know but I would rather have a frame which is taken up with all the detail that M51 has to offer.

Whats the next move? I've been reading some first light reviews of cameras like the 314L, which at £1000 new is not impossible to save up for and going by CCDCalc will give me a much tighter fov and hopefully what I'm looking for.

What other cameras out there are going to give me that sort of image?

I'm at the moment leaning toward OSC as actual scope time isnt at a premium due to young children and a non permanent setup. I would love to go mono with narrowband but that will come later down the line.

I think most of my problems come from me personally never being happy with what I've got, I think I have most of the setup in place with the NEQ6 Pro, Equinox 120 and guiding in the form of a QHY5 finder/guider. I just need to find the right camera.

Sorry for the rant but I know you guys will understand.....well I hope you will.....lol

[Beyond_Vision]

Unfortunately you have come across the age old problem of one scope and camera combination doesnt cover all targets. Just like normal daytime photography a range of focal length scopes and or CCD chip sizes is required. The DSLR is fine for objects like large nebulae such as the NAN, Rosette, Horsehead and Flame, M42, M45, Elephants Trunk etc. There are a large number of objects like these and you can also frame several objects in the field of view. The worst time of year for this sort of set up is in the spring as galactic plain is not well placed and hence it is called the Galaxy season.

Regards

Kevin

[FraserClarke]

Wow! It's not often you get people complaining that they've got too MANY pixels!!

If the DSLR gives you too much field of view -- why not just crop the image down in photoshop afterwards??

Remember that the telescope delivers a fixed size image to the camera. How many pixels the camera has only determines how much of that image is captured. Changing to a camera with a smaller number of pixels is not going to make any difference to the resolution you can achieve with that telescope. All you get it a smaller image out of the camera.

Canon 1000d has 5.7 micron pixels. Your scope has a focal length of 900mm. So, your camera plate is 1.3"/pixel -- a pretty damned good match for UK conditions to be honest.

Atik314L has 6.4 micron pixels, so the plate scale would be 1.45"/pixel; only 10% larger than with the Canon.

The only difference between the two cameras is that the Atik has 8x fewer pixels! If you crop out the middle 1300x1000 pixels of your Canon images, you'll get exactly the same result.

If you want better *resolution* on the target, you need to look at increasing the focal length of the telescope. To be honest however, in the UK you'll struggle to get <2" resolution for long exposures, so there is not much point in having a pixel scale less than 1"/pixel. You're pretty close to an ideal set-up in terms pixel scale/field of view already I'd suggest. Maybe just need to do a bit more post-processing to focus on the pixels you're interested in?

(Of course, there maybe be differences in sensitivity between the cameras, etc -- but it doesn't sound like that's what you're worried about?)

[Deneb]

Are we really fed up or was it just a bad night ? I know mine was last night & it was really clear ! Where things went wrong - they did. I think your going to break my record on changing gear...

Personally you should hang in there for a little while longer, before making any hasty moves/changes.. Just some thoughts...

Nadeem.

[tooth_dr]

Just search on here to find all the fantastic images taken with DSLRs. Don't expect perfection in a short space of time if you've only got the camera. Take your time and you'll soon love it. Cropping helps you remove distortions etc at the edge of the FOV too

[glennbech]

Hi,

I think Tea Dwarf makes a good point here. The Canon 1000D has more pixels than the Atik, it is just a matter of cropping.

The only real advantage the cooled CCDs have over the DSLrs is the sensitivity and reduced noise that comes from cooling, and

the design of the sensors. You get around that by taking more light frames and heaps and heaps of calibration frames like darks and flats.

For me THAT is the biggest hurdle of DSLR imaging (That makes me saving up for a water cooled CCD)

What you should do, if you're not there already, is to be very very very carefull about focus. If your focus is right and seeing fair, your can

use most of the available pixels in your resulting image. I have more than once been sloppy about focus and just reduced the image size from a DSLR scale

to a typical CCD scale to get sharper stars. That is just lazy.

M51A&B is about 320" x 258". This translates to 464 x 361 pixels. If you crop out an area of 1200x800 from your stacked image, you end up with

a galaxy pair that fills about 1/3 of the frame. Not BAD! :-) The DSLR has another advantage as well, the possibility of real wide field imaging.

I took this image of M33 with my Megrez 90 and canon 10D last year. It is a good example of cropping (and not resizing).

I have now imporved my focus even more with the Bahatinov analyzer software :-)

Keep it up!

[glennbech]

Oh... And you NEQ6 can carry an 8" reflector as well. They're cheaper that the more expsensive CCDs and a good addition to your setup for visual use as well.

I modified my 8" Newt with a moonlite focuser and invested in a coma corrector for photography... My problem is that I can't get it to guide well on my overloaded HEQ5 Pro...

[Ben Ritchie]

Agree with the comments here, imaging is a succession of lows where nothing works properly and then suddenly it comes together and you get a result that makes it all worthwhile. Been there, done that, got the T-shirt.

It's very easy to try and throw money at the problems (been there, done that too) but it's really worth trying to pick targets that suit your setup and work through things step by step, you'll get there. If you try and rejig your setup after every frustrating night then it'll get expensive very quickly.

[MarkF]

Keep in there Si, I just sent you a rather long email about my initial trial and tribulations, hopefully that will motivate you, stick with the DSLR for the time being.

Its only been three weeks since I started this lark but I think I have made most of the mistakes now new one last night was forgot to plug in the ST4 cable to the mount, took five calibration attempts before I worked that one out

Then of course cloud had rolled in and everything had dewed up.

[johnrt]

Agreed - stick with it.

The two biggest and easiest leaps forward you can make are modding the camera and getting the guiding down for some 5-10 minute length subs. You will see a world of difference once you have both of those in place.

You can crop the centre of your image and upscale it if needed in photoshop, pi etc etc.

[Sparrow]

Don't be disheartened. I've been using the 1000D (unmodded) now for a year and the results are getting better. The comments about the right target are spot on. There is no one set up that will do everything. Ultimately I'd love a dedicated CCD camera but cost is prohibitive at the moment. There are plenty of targets that your set up should be suited to. I'd suggest you download and install CCDcalc - a fantastic program that I often use - you can see in advance what sort of image scale you will get with a given scope and camera. (CCDcalc doesn't list the 1000D but it does list the Canon 400D which I find a close enough match.

As for M51 - I've attached one of my early images from last year - taken with the 1000D through my 8" newt. Now I've got guiding sorted I'm hoping to increase magnification on this target next time.

[simon84]

Thanks guys, going through some personal problems at the same time hasnt helped at all but reading your messages has given me some encouragement.

I'm not going to mod the camera, its still got a years warranty on it so there really is no point wasting that.

I really want close up images, your image of M51 sparrow is awesome, I really like the detail, but honestly if I get an image like that and then crop it to the same size fov as a 314L am I really going to be looking at a better image than what the 314L would give me.

Guiding is going well and I can get really decent polar alignment and I am now making plans at keeping the mount head outside setup on the pier permanantley, that was one of my biggest bug bears having to tear it all down every night.

The other is never being able to get out there imaging, I hate the weather this country throws at us and I am starting to believe that the chances of a clear night at new moon are ni on impossible.

I will stick at it with an unmodded camera. I know what I want and widefield images with a small DSO in the middle of it isnt it. I will try cropping the image but I'm worried that I will lose too much detail, but its got to be worth a go.

I cant see that a 1000D is better than a 314L at all as that is probably one of Atiks best selling cameras at just over a £1000 and if that was the case I'm sure everyone would be spending £700 less for a 1000D.

I guess for now I keep plugging away and keep saving up for that QSI 583WSG.......thanks again though for all the words of encouragment, I really do appreciate it.

[Ben Ritchie]

I really want close up images ... I know what I want and widefield images with a small DSO in the middle of it isnt it.

The downside to glorious close-ups is that it introduces yet more sources of frustration - seeing and very accurate guiding. Because those image scales show up every flaw in your setup (under/over-agressive guiding, flexure, backlash, etc., etc.) and you may have a beautiful clear night but Pickering 3 seeing where everything's a blob, especially in the blue channel.

The solution ... pick large DSOs in the first place. You'll never run out with the limitations of our weather. Fill the FOV, and life's much easier when you're working (implicitly or explicitly) at 2.5"/pixel.

[johnrt]

I really want close up images, your image of M51 sparrow is awesome, I really like the detail, but honestly if I get an image like that and then crop it to the same size fov as a 314L am I really going to be looking at a better image than what the 314L would give me.

Maybe not "as good" but certainly better than I think you're expecting. I'm not saying my image is outstanding by any means, you'll find MUCH better than this, but it's a decent example. 2 hours, 5 min exposures, unmodded 1000d focal length 750mm, cropped and rescaled in pixinsight.

[themos]

I will try cropping the image but I'm worried that I will lose too much detail

You will lose a lot of the surrounding star field, but why would you lose detail in the DSO? You are keeping all the pixels from THAT.

[simon84]

I think I will just spend the next year imaging whatever I can, I have fairly limited skies for my spot in the garden, so its not like I have alot to choose from. There really is no point taking this setup out into the field when I'm struggling with it at home.

[dph1nm]

I will try cropping the image but I'm worried that I will lose too much detail, but its got to be worth a go.

There seems to be some misunderstanding in this thread somewhere. Cropping won't lose detail on the DSO, and as others have set you will end up with an image of roughly the same size and resolution (i.e. the same amount of detail) as the Atik. The Atik is more sensitive, so will get you there in a shorter exposure, but why do you think it would give a more detailed image?

NigelM

[simon84]

Its much better than I expected. I guess the bottom line is to just get out there and take some images with the darn thing and try it out

I'm about to go and set it all up now and start making sure its all working ok.

The guiding isnt an issue really with the QHY5 finder/guider, it seems really reliable, I still have a lot to learn with regards to things like over agressive guiding and all things like that.

I forget that even though I've been into astrononmy for just over a year now, my actual scope time must only be something like a couple of days total, which isnt alot at all.

I'm sure it will all come with time but for now I'm trying to keep things simple with the NEQ6 run with EQMOD and Carte du Ciel, camera controlled by a timer remote, as much as I like APT I dont like running everything from the laptop. I'm almost tempted to drop EQMOD and go back to the handset but if I ever go permanent it needs to be setup so that I can operate it remotely, and guiding with PHD.

[simon84]

Sorry I'm getting cropping and re-sizing mixed up.

[tooth_dr]

Here is my M51 with a modded 300d, and SW 250px fl=1200mm. The 1000d is MUCH BETTER!!

[Beyond_Vision]

I think you are missing the point by getting fixated on a target like M51. You need to pick targets that fit the FOV of your system. There are plenty of targets to go for especially this time of year. When you get more experience under your belt you can then go for longer focal length galaxy imaging.

Regards

Kevin

[LukeSkywatcher]

Sly............you say M51 just looks like 2 stars amongst other stars.

Sorry to state the obvious but have you tried taking multiple images and then stacking them?...using DSS.

If so....then ignore this comment.

[milan]

SlySi84, Im following behind you so am relying on your for guidance (take my QHY5 woes for instance) I got a Megrez 90 last year and expected to hook my Canon 5D up and get instant results on my first target (M31).

Unsuprisingly i didnt and i got really disheartened, a few personal things then got in the way and ive hardly touched the scope for a year. Ive now got some more free time and also the QHY5, which im hoping will help a lot but i know there is still a long way to go. I really struggled with the processing last time and i think it was that element which brought on my disappointment.

Anyway, after looking at some of the gorgeous shots achieved on here with DSLR's the other month it reignited my desire to get some DSO' so im back here trying again. I still need to work out some good targets to start off and i completely get you want the DSO to fill the image and not be a dot in the corner, im with you.

i would love a nice CCD but im going to stick with the stuff i have now (apart from the dew heaters im yet to buy and will no doubt need) and learn the art. No doubt i will be cropping a few images along the way and asking for plenty of advice!

Got any tips?!

[simon84]

Thanks for all the kind words guys, I know what the problem with the system is, its me. I'll get there, just need to slow down.