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Old 23-11-2007, 10:17 AM
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DSLR v other

Hi
Wanting to more astrophotography, but am one of little patience. What is the easiest to use? I have a Toucam but not happy with the results, which is why it nearly landed over the neighbours fence. Do I always have to go stacking a multitude of pics for satisfactory result? I note that a lot of you have both DSLR and toucam and more (DMK.../GXstar etc). I think most DSLR only do about 30sec exp, and those other CCD do more. I am prob looking at more planetary stuff (and fading comets) , but 'EASY stick in scope and shoot stuff', is that possible??? Would a DSLR be the better option? Have backtracked over a few threads, but not found the answer. Many thanks.
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Old 23-11-2007, 10:37 AM
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Easy stick in scope and shoot costs money - ie dedicated Astro Imaging CCD cameras. Doing it on the 'cheap' has it's drawbacks.

Cheers
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Old 23-11-2007, 10:41 AM
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Kal (Andrew)
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In a simple answer - no. For planetary there is no comparison between a toucam and a DSLR, the toucam wins hands down.

With regards to planetary imaging, the only way you are going to get decent results comparable to what people are capturing nowdays is by stacking multiple images - if you used a DSLR for a single shot then you will only capture images slightly better than what astronomers were capuring 15 years ago - which is way below the standard that most people are getting nowdays.
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Old 23-11-2007, 11:52 AM
Dennis
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Hi Liz

It is almost impossible to “dabble” in astro photography without incurring cost and some frustration – welcome to the long suffering club!

Cameras such as the ToUcam and DMK excel at high resolution Lunar and Planetary imaging because they capture 10’s of frames per second. Software can then “grade” those frames and only stack the best, giving some quite extraordinary results for a relatively low cost start up.

However, when we move onto long exposure deep sky imaging (Deep Sky Objects or DSO’s) then costs, demands on equipment, set up complexity, time and operator patience begin to increase, sometimes exponentially!

If we mount a DSLR with a typical kit lens set to say 50mm focal length on a polar aligned telescope that has an RA motor for tracking, then you can take some nice wide field images but again, stacking these will make them look richer as it minimises the noise and strengthens the signal. You may spend as much time processing your image sets as you did in acquiring the data!

As soon as you fit a DSLR or dedicated astro CCD camera to the focuser a telescope (prime focus), then you place great demands on the entire imaging system. This includes but is not limited to items such as the quality of the ‘scope, collimation, accurate polar alignment, low periodic error in the mount, good tracking or better still, auto guiding, etc. This makes the game more expensive and also potentially more “frustrating” especially if you have a portable set up and need to assemble, align, focus, calibrate, test, etc. the set up each session, then tear it down before going to bed, or work!

However, if this is your chosen path, you will be well rewarded with some amazing results and there has never been a better time in terms of equipment availability, albeit at a price! You can sometimes “cut corners” or do things on the cheap, but this usually increases non-productive set up, fault finding, system tuning time versus quality imaging time.

Cheers

Dennis
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Old 23-11-2007, 12:49 PM
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Thanks guys, yes was afraid those would be some of the answers. Am prepared to pay few $$ tho, as dont have a DSLR yet. Would a 'dedicated Astro Imaging CCD Camera' still be complicated, causing much frustration
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Old 23-11-2007, 12:51 PM
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iceman (Mike)
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Yes! There really isn't one camera that will do both planetary and deep-space photography well.

They're different objects, requiring (usually) different telescopes and different cameras, and different (but similar) techniques.
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Old 23-11-2007, 01:11 PM
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ving (David)
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hiya liz,

I am afraid that when it comes to taking hires planetary shots as you want to do the toucam is probably the easiest way to do it as well as teh cheapest... a DSLR just wont do the job for you when it comes to planets at all. I havne used the astro specific cameras like the dmk but i am asuming they too are more complex than the humble toucam to use...

I guess if you get a DSLR you could take long exposure shots of DSOs in the bulb setting that pretty much lets kyou open the shutter as long as you like, and you could use it for day to day picture taking too... but dont be fooled into thinking that DSO pics are easy to take either, trackig needs to be prefect, the exposure(s) not too long or short and multiple images of different exposure lengths need be stacked and then processed in picture editor... etc.

best of luck in whatever you come up with
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Old 23-11-2007, 02:30 PM
Dennis
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Hi Liz

It is wise to think long and hard about this decision!

A dedicated astro ccd camera is an excellent choice for long exposure auto guided astro photography of wide fields (short focal length), and close ups of galaxies (long focal lengths). The cameras and software were designed by astro photographers and so are really ideal for that purpose.

From a personal perspective, I was recently faced with a choice between upgrading to a largish specialised astro ccd camera (SBIG ST8, ST2000, ST4000) or a DSLR such as the Canon 40D.

After much deliberation, I decided that I would not be pursuing the masterful, exquisitely detailed, quality images that people such as Jase have been posting, AND I wanted a good DSLR for terrestrial use. So, we decided on the Canon 40D DSLR which I am hoping will be a happy medium that straddles both world’s to the degree that I am aiming for.

Cheers

Dennis
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Old 25-11-2007, 12:01 AM
Sharnbrook (Mike)
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I suppose all this can be summed up in the old adage:-

"You get out of it, what you put into it"

and to date, speaking personally, I have made very little effort in celestial photography, and so I have precious little to show for it.
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Old 25-11-2007, 11:21 AM
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I wonder if something like this might suit you:

http://www.myastroshop.com.au/guides/gstar/index.htm

You won't get the high megapixel images from it, but I wonder if it would be the ideal combination of ease of use and image quality for you?

I have not seen the GStarEX in person. I have seen the AstroVid Stellar Cam which I believe is very similar, and I was impressed how with it plugged in to a portable dvd player you could easily see nice images of globula clusters, planets, moon.

I think these camera's work by stacking frames internally, as specified by you through their menu system. You then end up with stacked images coming to the video screen.

As I say, I haven't used one, but do think it might be a good option for you.

Roger.
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Old 25-11-2007, 12:50 PM
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Thanks all for input, yes Roger, have had a look at that Gstar & looks good. Both have their pros and cons for DSLR and CCD cameras. Will keep looking at both and observing other threads. In the meantime I'II tackle the toucam again as seems to have great results, I have a 10" Dob and there seem to be a clash of personalties between them.
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Old 25-11-2007, 01:05 PM
Dennis
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Hi Liz

I have a great admiration for anyone who plugs a ToUcam into a dob – more so when it is manually "pushed to" than on a motorised base.

A few dob users here on IIS have produced some quite amazing Lunar and Planetary images with such a combo, before moving onto motorised platforms and later on, equatorial mounts.

Just keep shovelling bits off the pile of hard work and soon the pile will reduce in size and complexity, providing you with some surprisingly good results! I would probably start with the Moon at prime focus and just get the hang of focusing and manually tracking, possibly with the aid of an astronomical assistant in the family if one is keen and available!

Cheers

Dennis
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Old 25-11-2007, 02:02 PM
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Aaah, thank you Dennis, therein lies my problem - Toucam and Dob, yes, lots of trouble pushing it (also a sticky new mount, despite vaseline on the tape bits) and keeping subject on camera. Feel better now, as thought it was just me. Moon was the only thing that stayed in view.
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Old 01-12-2007, 03:00 AM
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I am new to this too, but not to digital photography. Someone a few posts back suggested that with a digital camera you could use "bulb" and take long exposures. You can't there is no such thing on a digital camera. 30 sec is the limit, not because of physical constraints (there are ways around that) but because of "amp noise" which in some cameras can get so bad as to make them unusable. CMOS cameras such as the Canon and very latest Nikon are better but you will still be stacking images and using dark frames etc to process a shot. Dedicated Astro cameras are cooled to make then quieter. DSLR are also physically large and this causes mounting problems as well. All very interesting if you want a challenging hobby but definitely not plug and play.

Roger
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Old 01-12-2007, 06:53 AM
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Hi Liz, you have been given some good advice from fellow IIS members! In my humble opinion a DSLR would be a great companion for the Toucam. You will be able to get nice whole moon shots and up closer shots with the right barlow or teleconverter and solar shots (with the appropriate filter) Do beautiful wideangle shots on a fixed tripod etc.. and if you enjoy this then you can try your hand at some piggyback wideangle shots with standard lenses (when you upgrade to a EQ mount or a suitable base) and short prime focus shots. Also you will have much fun taking everyday pics with your new toy. DSLR`s ,well everyone I have seen up close has a "Bulb" setting and you can take a image for as long as the battery lets you! I have seen over 2 hour star trail shots by a local! very noisey but you can do it! the Canon cameras have fairly low noise for a uncooled sensor thats why there are so many of us using them...then you can get them modded, but won`t go into that..
Dedicated Astro cameras are the ultimate for deepsky work but so is the learning curve as well as the complexity of setting up and processing, I wouldn`t recommend someone starting out jumping in the deep end!
With a EQ mount as well you should pull some nice planetary images as well! I can understand your frustration with a sticky push it Dob!
Get a nice DSLR and a mount that tracks and have heaps of fun...
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Old 01-12-2007, 07:13 AM
Dennis
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Quote:
Originally Posted by rogerco View Post
I am new to this too, but not to digital photography. Someone a few posts back suggested that with a digital camera you could use "bulb" and take long exposures. You can't there is no such thing on a digital camera. 30 sec is the limit, not because of physical constraints (there are ways around that) but because of "amp noise" which in some cameras can get so bad as to make them unusable. CMOS cameras such as the Canon and very latest Nikon are better but you will still be stacking images and using dark frames etc to process a shot. Dedicated Astro cameras are cooled to make then quieter. DSLR are also physically large and this causes mounting problems as well. All very interesting if you want a challenging hobby but definitely not plug and play.

Roger
Hi Roger

Both my Pentax *ist DS and Canon 40D have a “Bulb” setting. When I set the Mode Switch to M for Manual, turning the shutter speed control dial past the “30 sec” setting then activates the “Bulb” setting where I can hold down the shutter release for either 60 secs, 2 mins, 5 mins or whatever. I can also do the same using the remote software on a Notebook computer, so the user doesn’t have to sit there pressing the remote release.

You are right about noise though, but both my Pentax and Canon can automatically take a same length exposure Dark Frame in-camera and subtract it (the noise) from the light exposure, giving quite a reasonable result for a non-cooled camera. Stacking several of these exposures would then be required to improve the signal to noise ratio.

There is a post by Dave & Barb (Tamtarn) showing a superb single 300 sec exposure of the Tarantula here.

I’ve only dabbled at 2 or 3 mins so far, and I have not seen any evidence of amp glow yet? You are correct – it is a challenging task though, regardless of camera/sensor used; polar alignment, auto guiding, image calibration and processing, etc.

Cheers

Dennis

Last edited by Dennis; 01-12-2007 at 07:25 AM.
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Old 09-12-2007, 06:15 PM
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Yep, sorry for being so sure of myself. unfortunately I am a Nikon user. Canon is definitely the way to go. Read some recent review on the Canon 40d that look very good. Mirror lock up with live focus control to either large rear screen or computre screen. Nikon does have cable (electronic) release but this cannot be actuated through the USB port you need a modified calble release cable (expensive). Nikon have just brought out a new cmos series of cameras but I haven't seen details yet.

Roger
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Old 09-12-2007, 08:24 PM
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Quote:
Originally Posted by rogerco View Post
Yep, sorry for being so sure of myself. unfortunately I am a Nikon user. Canon is definitely the way to go. Read some recent review on the Canon 40d that look very good. Mirror lock up with live focus control to either large rear screen or computre screen. Nikon does have cable (electronic) release but this cannot be actuated through the USB port you need a modified calble release cable (expensive). Nikon have just brought out a new cmos series of cameras but I haven't seen details yet.

Roger
400D's are OK as well. I have taken 10 minute exposures with no in camera noise reduction and while there are hot pixels there is no detectable amp glow. The hot pixels can be removed with a dark frame.

I did notice amp glow on the 300d after about 5 minutes, but that was a two year old camera and is older technology.

Paul
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