# Explain CanonT1i brand new picture taker



## chiefdeck (Oct 12, 2011)

I have a Canon T1i with an EF18-55mm lens that came with it.How do I set exposure time for 20 or 30 seconds.Ihave it mounted on top of my telescope and I am trying to take pictures of moon and planets.Can somebody please explain what f/stop, iso is. For instance I have camera on now on M with top line of screen showing 1/20  F5.6 iso200 what does all this mean between my telescope forum and intruction book that came with camera I am now totally confused.


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## Big Mike (Oct 12, 2011)

Welcome to the forum.

First thing to do is RTFM.


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## JS_280 (Oct 12, 2011)

Big Mike said:


> First thing to do is RTFM.  ;-)



Really?  :no smile:

chiefdeck...since  you're new and possibly haven't yet learned all the smug, inside joke  acronymns...not to mention you said you already read the manual...

The settings you see are your shutter speed (1/20), your aperture (F5.6) and your ISO (200).

F-stop is a numerical representation of the size of the lens aperture which will control the amount of light that hits the sensor as well as your depth of field, which is how much distance is in focus simultaneously.

ISO is simply how sensitive your camera's sensor is to light.  The higher the number, the more sensitive it is...as well as the more noise (graininess) you will add to the image.

To change your shutter speed:

While  holding the camera, roll the small wheel behind the shutter button.   You should see the number go from fractions of a second up to 1" (1  second) and then up to 30" (30 seconds) and then "Bulb" (shutter stays open as long as you have the shutter button depressed).

To change your aperture:

Roll the small wheel behind the shutter button while depressing the "Av +/-" button at the top right of the LCD display.


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## chiefdeck (Oct 12, 2011)

Thanks JS_280 for the response it helped me along.As far as Big Mike I am amazed that you are the site moderator,what an off the wall response.If you read my post you would have seen that I had read the manual and was looking for help and clarification something sadly missing in your comment.Are you not  suppose to read the post's to be able to moderate them,apparently you do not.


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## Big Mike (Oct 13, 2011)

The questions you asked, are answered in the manual.  Perhaps it would be to your benefit to read it again.  Don't just skim through it and then ask people for help, telling them that you read it already.  
I'd also suggest reading up on the basics of exposure.  Namely, shutter speed, ISO and aperture.  Having done that, you should be able to ask more knowledgable questions and properly understand the answers you might get.

I apologize for being snide.


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## ScubaDude (Oct 15, 2011)

With the kit lens, the moon is going to be very small and planets are out of the question (Jupiter is pretty bright right now, but will just look like another star). What make/model telescope do you have? Does it have motorized tracking? Your best bet would be to get an adapter that would allow you to mount the camera, with the lens removed, to the focuser of the telescope. The telescope then becomes the lens.


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