Srbhai
member
Reged: 08/29/06
Posts: 96
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hey guys, i've been on the board for quite a while and have asked zillions of questions regarding scopes and binos and cameras..
finally i have bought a Rebel Xt with the 18-55mm lens... which is infact 28-80mm ...after 1.6x conversion. i put everything i had in this camera ... so im not left with any money to buy any fancy lenses or telescopes .. for now .. lol.
so my question is .. wut are the possibilities of this lens towards astrography ?
i dont expect it to dooo really well like the telescopes or fast fixed focal lenght lenses ... but just a rough idea of wut to expect.
I would like it if u guys told me some good targets and some basic settings that would be good for this kinda photography .. i have a alt/az tripod ... for the moon i tried 1/70 sec and 100iso .. but want more detail .. any suggestions?
i also want some settings for Dso like orion or andromeda .. or planets ..
wat exactly is this image stacking that everyone is talkin abt ? And what is the use of post processing >?
my questions are probably too basic .. but sorry cant help it.
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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NeoDinian
Experienced Postmaster
Reged: 10/05/05
Posts: 14043
Loc: Rockford Illinois
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Can't answer all, but I'll help with some basics. (I'm new to Imaging)
Stacking is taking multiple frames and "Averageing" them together. The benifit is being able to take shorter exposures so you don't bleed the image with skyglow and other problems. There are several software packages that do this for you.
Post processing is really the key to astro imaging. If you were to look at an un-processed image, there would be very little to see. You need to to the processing to bring out the faint parts of what you're imaging. The use of Darks, Flats, and Bias frames also help to filter out the unwanted data from the image..
Camera setting will differ from person to person, and the day it was taken because of your local sky conditions (Skyglow, temperature, humidity, ect...).
The stock lens for the XT is not the best, but you should still get some decient widefields with it. Someone else here can help with the How-To of it.
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Neo... (Jeff)
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10" LX200-GPS/SMT UHTC "Draco"
 Rockford, Il.
NeoDinian's Eye on the Sky!
Coming soon:
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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try experimenting w/ a wide field of the orion constellation experiment w/ the different ISO settings and exposure times its a good way to start. I would suggest 1500 as an ISO w/ at least a 30 sec exposure
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----Calvin Sereda
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Srbhai
member
Reged: 08/29/06
Posts: 96
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will i have any luck with planets? or galaxies .? i dont have a guided mount .. so is there a slightest possibility ?
any otther good targets? like ring or dumbell or any clusters?
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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there is the slightest chance fpr dso's if you were to use raw then convert it to a tif and enlarge it to see it but it would not be the best image in the world so you would probably need (for DSO's) at least an 80mm refractor on a goo-to az mount like the meade etx 80 or for more money and higher quality the orion sirius 80 mm apo combo
or there is the Meade LX90 GPS series
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----Calvin Sereda
Edited by CRSEREDA (10/08/06 03:25 PM)
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Srbhai
member
Reged: 08/29/06
Posts: 96
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wat abt planets ?
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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it should be able to do larger planets and the moon
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----Calvin Sereda
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Srbhai
member
Reged: 08/29/06
Posts: 96
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wat exactly do i need to do . to stack images? wat is the procedure for stacking images ? which software to use ? please provide a link if its free. which software for color adjustments? i have photoshop Cs
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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registax or registar for stacking images photoshop CS is fine for post procssing of your images or there is IRIS which is free but is very complicated to use
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----Calvin Sereda
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Srbhai
member
Reged: 08/29/06
Posts: 96
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could u suggest any particular settings like shutter speeds and iso and focal lenght for planets?
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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ccvle
sage
Reged: 08/10/05
Posts: 228
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You have to figure that yourself. There's no one magic setting that will work for all camera and scope.
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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the iso and focal lengths for planets will be different depending on the atmosphereic conditions
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----Calvin Sereda
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Andrew Welsh
Carpal Tunnel
Reged: 03/28/06
Posts: 2571
Loc: Rochester, NY
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Quote:
what abot planets ?
At the 55mm setting you might be able to resolve the moons of Jupiter. I did it with 70mm of focal length, and I suspect 55mm would too. But other than that and noting that saturn "isn't round" you won't get much by way of direct planetary imaging. you still can make nice composites of conjunctions or sunrise/sunset type photos.
Use ISO800 or 1600 to cut down on star trails (i.e. get the most light at the shortest shutter speed) and stop the lens down one or two stops (f/5.6 or 6.3) to make the stars rounder and sharper.
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LX200 8" classic, f/10, Meade eq. wedge, .63x FF/FR
Canon 40D (LifePixel clear glass mod) and 5DMkII, unmodified
Canon EF 200/2L IS, 400/5.6L, 100/2.8 Macro, 50/1.4, 85/1.8, 35L, 24L, 17-40L and Peleng 8mm fisheye
Orion Apex 102mm (4") Mak-Cass
Pimped out with accessories and bling
My DSLR Astrophotography Webpage and photo bucket with full equipment list
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Srbhai
member
Reged: 08/29/06
Posts: 96
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thanks guys .. but i still dont understand the meaning of image stacking? could u explain it in plain english please.
can the Xt be controlled via a computer? i mean can the shutter be kept open with having to press down the shutter release button all the time?
Is it possible to make some kinda release cable or somethin ?
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Equipment:-
10-30X25 Crown ruby Binos.
Canon Rebel Xt/350d
18-55mm Canon lens
Eyes with natural FMC and Transmission coatings
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CRSEREDA
sage
Reged: 01/07/06
Posts: 386
Loc: Davie Florida USA
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Image stacking is the process of combinging and taking the average of the composite of images to get a hihger quality image, and you can add or subtract certain types of the image to take different things out like noise.
The Canon D. Reb. XT can be controlled via computer by using the program DSLR FOCUS its an easy to use and easy to explain program
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----Calvin Sereda
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JackProton
sage
Reged: 03/01/06
Posts: 314
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If you're good with a saw and hammer, look up instructions on how to build a "barndoor tracker". Basically, its two pieces of wood, a hinge, a camera ballhead and a tube for sighting Polaris. Its a cheap and easy to build, human powered tracker that'll let you do 5 minute (give or take) widefield exposures with your camera.
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Aquarianperry
sage
Reged: 02/01/04
Posts: 330
Loc: Durham, NC, USA
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I'm in the same boat as you, I picked up a good deal on a DR XT this past weekend, I had done a lot of research on it earlier on so I prepared by purchasing these items as well:
Remote Control RC-1
Opteka Battery Grip (Holds 2 Rechargable battery kits
Orion T-ring Adaptor
Tamron Dii 70-300mm Lens and Tamron 28-105 Lens (For Daytime Play and Constellation shots)
This should hold me off for a while for daytime tinkering and nighttime work (once the clouds clear up, cloudy night syndrome applies to DSLR purchases too  ). I'll keep track of this post to see how you do.
Canon 50mm 1.8 Lens (For detailed portrait work)
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Orion SVP8 "Brute"
Hardin 80/6 "Stella"
Orion Starmax 90 "Magnet"
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Bryan_KC
member
Reged: 09/08/06
Posts: 45
Loc: Olathe, KS
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Quote:
can the Xt be controlled via a computer? i mean can the shutter be kept open with having to press down the shutter release button all the time?
Is it possible to make some kinda release cable or somethin ?
Get the Canon RC-1 remote. It runs about $25 from B&H, Adorama, etc. Do not get the RC-5, it can't control bulb shutter setting so you're limited to a fixed shutter speed.
Let me know if you can't find it and I'll post links.
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Bryan in KC
Where'd all these clouds come from???
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Celestron FirstScope 114 EQ Shorty
Meade ETX-90 EC
Oberwerk 8x56
Canon Digital Rebel
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gavinm
Pooh-Bah
Reged: 08/26/05
Posts: 1449
Loc: Auckland New Zealand
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A shutter release cable can be made for about a dollar - it's just basically connecting two ends of a 2.5mm stereo plug (but I rarely use mine - 30 sec isusually good enough)
If you are unguided, i would recommend 30s at 800ISO (assuming you are piggybacking). If unguided means "on a tripod" then 15 seconds is about the maximum exposure (to remove star trails) and even then, it depends where you point it. You can get some great, wide field images at 18mm using the basic EF-S Canon lens (chromatic abb is ok, spherical abb is more of a problem around the edges, but still a good lens for free)
practise processing images to bring out the details using photoshop to start with, and then move to stacking multiple images (again on photoshop - a bit rough but pretty easy)
Canons take great photos 
good luck, enjoy and keep asking questions
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Gavin
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gavinm
Pooh-Bah
Reged: 08/26/05
Posts: 1449
Loc: Auckland New Zealand
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2 x examples using a 300D, ISO 400, 30s f 2.8 (too large really to be honest) using a Sigma 70-200 2.8 EX APO lens at 200mm
Both are piggybacked but unguided (and slightly out of focus.. sorry.. I was rushing)
The first is Jupiter.. cant see much but a disc and some lovely diffraction spikes.. so planets are OK, but disappointing
The second shows a cluster (can't remember which one - probably Omega Centauri - coz i live in the south pacific).. so DSO's are OK too
Neither photo is processed (I think.. my memory has gone since I got married)
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Gavin
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