350d astrophotography tips @ 30 sec. exposure for bext pix?

[Megan Milligan]

My sweet beloved S/O bought me an adapter for my birthday to hook my 350d up to his telescope to try to take astro pictures.

now my question is: this is my first foray into astrophotography. I know there is equipment I need to get to extend the shutter time beyond the standard 30 seconds in the 350d. But until I get that equipment what are some good tips for maximizing the maximum 30 sec exposure on my 350d to get the best astro pix I can? i've found a few good web resources, but i'd like your opinions

and would it help to use my 2x teleconverter for more close-up pix?

and as a side question, with $$$ being a factor, what are the most economical but best side equipments I can get (and where to get them) to extend the exposure time beyodn 30 seconds? Thanks!

 

[adamheffer]

now i don't have a DSLR yet, i'm still reading up about it before taking the plunge from my Canon Powershot A70...but this is what i've learnt after reading up about it today...

in order to have a long exposure time you need to get a device that holds the shutter open...this holds it open till you let go...this can be either a switch on the end of a wire or you can get an infrared one.

i think the longest the 350D will hold the shutter open for is 15 seconds which probably ain't enough to get movement....

i'm sure someone will come and correct me

 

[rjalex]

Longest built in shutter is 30 secs.
--
Bob
If two people agree on everything one of them is redundant.

 

[onlyonejc]

The longest the 350D will expose for is 30 seconds using the timed shutter speeds. Although:

I gather the telescope is set up using a tripod, right? So, why don't you set your shutter speed to 'bulb', and manually expose your pictures. This will give you an infinite amount of exposure time in order to achieve the correct exposure. It will take a little getting used to, but once you hit a sweet spot, you'll be all set.

onlyone-jc.

 

[Aerogel]

This depends on many factors:
Does the telecope track the sky?
Does it have a quality tracking system?
Are there problems with light pollution at your location?

The 350D can expose for many minutes using the bulb setting, but without a remote shutter release, you'll have to use a method such as covering the telecope aperture for a few seconds before and after you hit the shutter button so as not to expose the initial shake and probably a few seconds before you finish the exposure.

Most tracking telescopes are pretty poor at following their subject accurately enough for long exposures anyhow. A much better solution might be to use shorter exposures and then stack them in software such as RegisStax (registax.astronomy.net). Even on a static tripod with clear (non light-polluted skies), good results can be had with stacked images.

Instead of a teleconverter, try and use a barlow lens if he has one...

Ian

 

[Megan Milligan]

It's a manual telescope. the best way i can describe it is that it's shaped like an exclamation point as opposed to a "traditional" telescope. i've read about the "bulb" setting and will look at my camera more after I get home from work. thanks!

 

[Aerogel]

With a manually guided telecope, don't even think about exposures above 5 seconds - you'd have to factor in the time taken covering the aperture for the final exposure value (mind you don't touch the scope, just shut of the light with something - traditionally, a hat). Even with a remote shutter release, you might still need to cover the aperture for a few seconds after release to stop the shake induced by the shutter itself. I use a hacked 300D which allows mirror lock-up to achieve the same result.

You can still get good images of the moon, but even then, some sort of remote shutter release will be needed for good results unless you use a higher ISO setting and very short exposure time (500th+ if through the telescope and a light touch on the shutter).

Why not consider fixing your camera to a fixed tripod with a reasonably wide angle lens pointed at the Milky Way (or whatever). Then you can stack, say, ten images taken at 10-30 seconds exposure and see what comes out...

You're out there in Nevada, you've got to have better views than we do here with the orange skies of the UK...

Ian

 

[Megan Milligan]

You can still get good images of the moon, but even then, some sort
of remote shutter release will be needed for good results unless
you use a higher ISO setting and very short exposure time (500th+
if through the telescope and a light touch on the shutter).

Actually, I have taken fairly decent images of the moon at 100 ISO and 1/1000 shutter speed with my 70-300mm lens (not too close up), and I hope to try the same thing now that I have a 2x teleconverter to go with it (i can't afford a major telephoto lens that i'd adore at the moment).

Why not consider fixing your camera to a fixed tripod with a
reasonably wide angle lens pointed at the Milky Way (or whatever).
Then you can stack, say, ten images taken at 10-30 seconds exposure
and see what comes out...

I'll give that a go & see what I get. I have buy a decent tripod though now that I lost the camera mount for the one I have at home.

Another tip I read about was using time delay to minimize camera shake when pressing the shutter button.

You're out there in Nevada, you've got to have better views than we
do here with the orange skies of the UK...

Definitely here. One of my favorite places to shoot & stargaze is a place called red rock canyon, but i'm also (if the sky is clear because it's been rainy the last few days) going to talk my S/O into driving to Valley of Fire at night for some nightime stargazing & nightpix. We saw the most magnificient shooting stars last november when I was the principle photog for my friends' Star Trek Klingon wedding at the VoF. Luckily there are plenty of places to go in order to get away from light polution which Vegas, as much as I love it, has in spades.

 

[Aerogel]

Actually, I have taken fairly decent images of the moon at 100 ISO
and 1/1000 shutter speed with my 70-300mm lens (not too close up),
and I hope to try the same thing now that I have a 2x teleconverter
to go with it (i can't afford a major telephoto lens that i'd adore
at the moment).

I'm with you here, but through a telescope, it may be like using a 1000mm+ lens...

Another tip I read about was using time delay to minimize camera
shake when pressing the shutter button.

Yes absolutely, but when the shutter fires (whether by delay or remote release), it still imparts a small vibration which can be significant when using a telescope.

Definitely here. One of my favorite places to shoot & stargaze is
a place called red rock canyon, but i'm also (if the sky is clear
because it's been rainy the last few days) going to talk my S/O
into driving to Valley of Fire at night for some nightime
stargazing & nightpix. We saw the most magnificient shooting stars
last november when I was the principle photog for my friends' Star
Trek Klingon wedding at the VoF. Luckily there are plenty of
places to go in order to get away from light polution which Vegas,
as much as I love it, has in spades.

Now your just rubbing salt into the wounds ;-) I remember the night skies when I was out in the Mojave and Arizona, years back... Stopped in at Vegas, but as you say, didn't see much sky.

I have also done some wedding photography for friends, but they usually got their photos just as they were getting divorced...

Ian

 

[marom]

the following websites:

http://www.bahneman.com/liem/photos/tricks/article.php?story=20051007132635145

http://web.canon.jp/Imaging/astro/index-e.html

Haven't tried it myself, because I don't have a telescope, first saving for a nice telelens for my camera.

Good Luck

 

[strikeback03]

a Klingon wedding? that had to be interesting. was there any gagh or blood wine involved?
--
http://www.linelight.org/

 

[ScottyNV]

as others have pointed out, a remote shutter release is mandantory for 'scope work.. also, the 350/XT has mirror lock up with shutter firing 2sec later.. so no worries on the vibration question..

yes, you can use your TC to magnify the image, however you start to get a very small slice of the sky, and guiding the 'scope becomes a problem..

in Bulb mode, you can hold the shutter open for many many seconds.. but the battery will not last for many shots, so best to use the BG-E3 vertical grip and two fully charged batteries to start with.. and have a third handy to swap in when the first two die..

what kind of mount is your telescope? some are easier to adapt to motor drive (a necessity for tracking and long exposures) you can get by with 'stacking' a series of shorter images, but your framing needs to be very good in order to do this effectively.. also, what are the details of your 'scope? focal length? aperture?

the Canon astrophotography guide (http: web.canon.jp/imaging/astro/index-e.html) is a good place to start researching..

note that there is unlikely to be electrical contact between camera and telescope, so you are in Manual mode for your exposure.. AWB should be fine..

Enjoy!
Cheers,
Scotty
--

• How deep does the Rabbit Hole go? *

Free the Images
My XT IS Full Frame -- APS-C/FF of course!

 

[rjalex]

Megan,
from what you describe your telescope sounds like a "Dobsonian" mount.

http://en.wikipedia.org/wiki/Dobsonian

This type of telescopes are not suitable for astrophotography since they do not have an equatorial mount.

Marvelous to do visual astronomy though !!

Take care
--
Bob
If two people agree on everything one of them is redundant.

 

[Megan Milligan]

I dont' think its a dobsonian mount based on the information that you gave me (& looking up other types of telescopes).

it sounds more like a Newtonian Reflector, which from the picture I saw, is closer to the "exclamation point (round bottom) telescope my boyfriend has.

 

[Megan Milligan]

It looks similar to this telescope:

 

[rjalex]

Megan,
I am sorry but your STILL looks like a beautifully small dobsonian.

The Dobsonian is characterized by a so called Alt/Az mount which means that you can move it in the vertical axis (altitude) and the horizontal axis (Azimuth). The newtonian is the optical setup built with two mirrors and a side ocular as in yours and has nothing to do with the mount.

In order to be able to track the celestial bodies, your telescope, be it newtownian or refrative, need something called a POLAR MOUNT (as opposed to your Alt/Az) along with a tracking motor.

The latter is quite imperfect in most low end telescopes and will not track accurately for long times.

I hope this clears up some of my explanations (which I am painstakingly crafting in your beautiful but alien to me ,language)

Cheers. PS What is a S/O ???
--
Bob
If two people agree on everything one of them is redundant.

 

[rjalex]

Megan,

I can confirm that the pic you show is a Celestron 21320 which is an altaz AKA dobsonian mount. Not good for astrophoto maybe except for the moon which you can manage with very short exposures.

Bob
--
Bob
If two people agree on everything one of them is redundant.

 

[Megan Milligan]

Megan,
I am sorry but your STILL looks like a beautifully small dobsonian.

The Dobsonian is characterized by a so called Alt/Az mount which
means that you can move it in the vertical axis (altitude) and the
horizontal axis (Azimuth). The newtonian is the optical setup built
with two mirrors and a side ocular as in yours and has nothing to
do with the mount.

Thanks for the info. Like I said, I'm still new to all this astrophotography stuff.

In order to be able to track the celestial bodies, your telescope,
be it newtownian or refrative, need something called a POLAR MOUNT
(as opposed to your Alt/Az) along with a tracking motor.

The latter is quite imperfect in most low end telescopes and will
not track accurately for long times.

Well, if anything else, maybe i can get some nice abstract photography or backgrounds for some future digital art pieces I'd like to do. My boyfriend says he's now interested in astronomy again, and would like to get a good-quality tracking telescope when he can afford it. I think that has something to do with the enthusiasm I oozed when he got me the adapter for my camera to fit his current telescope. I already made note to try to get the polar mount sometime in the future when he gets a good telescope.

I hope this clears up some of my explanations (which I am
painstakingly crafting in your beautiful but alien to me ,language)

how is my language alien? Then again, I'm also a poet so that might have something to do with it. heh

Cheers. PS What is a S/O ???

S/O = Significant Other

 

[Megan Milligan]

Megan,
I can confirm that the pic you show is a Celestron 21320 which is
an altaz AKA dobsonian mount. Not good for astrophoto maybe except
for the moon which you can manage with very short exposures.

Thanks! The moon is getting a nice rounded gibous look to it, and me & my S/O were thinking of going to Valley of Fire tomorrow night to stargaze and see what pictures we can take with my camera & the mount for his telescope, however primitive it might be. At least we'll be away from all the noise pollution from Vegas.

Bob
--
Bob
If two people agree on everything one of them is redundant.

 

[DNAmaster]

To get serious, to get pictures sort of like what you see in books, you need a big scope.

Then you need a serious mount with correction for errors in the gear train. All gears have errors.
The mount has to be connected to a serious base ( a tripod or pier).
Then you need to align the base to true north - or use a field rotator.
You will need a guiding scope.
The whole setup weights 250 pounds and more.
At least with film, the exposure can last 30 minutes or more.
You will need a dew shield or heater to prevent the scope from fogging up.

The list goes on and on. If you were to get everything above, the cost of the camera is really a small fraction of the total cost. So you might as well get a dedicated astro-camera.

After this, you can get a fuzzy picture of a galaxy which is maybe 300 pixels across. Just go to some web site and look for amateur astrophotos. Some are very good but I would not buy all the equipment just to take them.

In the end, you would never get a photo as good as some of the free stuff you can download off the web - from the Hubble telescope page for example. These pictures are public domain too - since the public financed the scope.

So you have to ask if it is all worth it.

So I gave up on this. I agree that it can be a lot of fun.