Telescopes

Discussion in 'Digital Photography' started by amirsamy@gmail.com, Aug 3, 2007.

  1. Guest

    I bought a Nikon D80 and I want to take pictures of the moon, planets
    and stars. Does anyone have any idea how I can use a telescope to take
    such pics? What do I need to use a telescope instead of the lens (the
    mount...etc)?
     
    , Aug 3, 2007
    #1
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  2. daba6 Guest

    The most common (and simplest) way is to buy what's called a 'T-mount'
    adaptor or just T adaptor which you put on camera. Ensure you get one
    specifically for your Nikon because every different camera brand has a
    different mount.
    Unfortunately you won't be able to use the Auto / Program / priority-
    exposure modes or autofocus, so you will have to get used to working
    out the exposure in Manual mode, and focus with the telescope .
    Because T adaptors (or any that I've seen) don't have the little metal
    contacts which connects the lens to the electronic contacts inside the
    camera mount which makes the Auto functions work.

    Anyhow, once you've put the T adaptor on the camera you then insert
    the other end of the adaptor into the telescope focusing tube where
    the eyepiece normally goes. So the telescope basically becomes a very
    powerful camera lens.

    There are some types of T adaptor which allow you to shoot through the
    telescope eyepiece (depending on which model and size of eyepiece you
    have) which allows you to achieve much greater magnifications.

    Some common brands of T adaptor are Meade, Tasco (I think make one),
    possibly Celestron.


    On Aug 3, 6:36 pm, wrote:
    > I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?
     
    daba6, Aug 3, 2007
    #2
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  3. On Aug 3, 3:36 am, wrote:
    > I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?


    In addition to the T-Mount mentioned by someone else, there is
    "eyepiece projection." In this method the camera is held by a bracket
    so that it is exactly aligned to the center line of the telescope
    optics. There are a number of folks selling these systems, some ads
    in photo vendors catalogs, others in telescope catalogs.

    To use eyepiece projection use a low power eyepiece on the telescope.
    The higher the power of the eyepiece the smaller the diameter of the
    exit pupil (the cone of light leaving the eyepiece). It is VERY hard
    to align camera with a small exit pupil. You will get excessive
    vignetting if the alignment is not almost perfect.
     
    Don Stauffer in Minnesota, Aug 3, 2007
    #3
  4. Mark Sieving Guest

    On Aug 3, 3:36 am, wrote:
    > I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?


    Exposure times for the moon will be fairly short, but for planets and
    stars you'll need a telescope with an equatorial mount and motor drive
    to track the image. Exposures for deep space objects could be pretty
    long: several minutes or even hours for some things. With the D80,
    you're limited to 30 second exposures, I think, but you can take
    multiple images and combine them in post processing to get longer
    exposures.

    This website looks like it has all the information you'll ever need:
    http://www.astropix.com/

    (I'm not affiliated with the website in any way; I just did a Google
    search for "astrophotography" and this was the first thing that popped
    up. Still, it looks like a good place.)
     
    Mark Sieving, Aug 3, 2007
    #4
  5. Mark Sieving wrote:
    > Exposures for deep space objects could be pretty
    > long: several minutes or even hours for some things. With the D80,
    > you're limited to 30 second exposures, I think, but you can take
    > multiple images and combine them in post processing to get longer
    > exposures.


    Or you just use BULB and time the exposure with your wrist watch.

    Of course a remote control will help reduce camera movement.

    jue
     
    Jürgen Exner, Aug 3, 2007
    #5
  6. Jim Guest

    <> wrote in message
    news:...
    >I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?
    >

    You should find Michael Covington's book "Astrophotograpy for Amateurs". He
    describes 6 ways to get images from a telescope into a camera.

    The simplest way just uses the telescope as a very long focal length lens.
    For that, you need a tube and a T-mount. Both Celestron and Meade (just to
    name a few) sell such gear.

    I, however, use my 300mm f4 with a 2x converter to take shots of the moon.
    I have found that, with iso of 200, 1/60 second with the lens wide open is
    satisfactory. The resulting image is not quite big enough for my taste.

    The image size of the moon is f/110. Hence, I only get a moon which is
    about 6mm diameter. It needs to be bigger, but getting it bigger would
    require spending money.

    I mount the camera and lens on a Bogen 3021 tripod (not quite solid enough)
    with a Bogen 3029 head. I use the self timer to eliminate as many
    vibrations as possible.

    Jim
     
    Jim, Aug 3, 2007
    #6
  7. Rich Guest

    On Aug 3, 4:36 am, wrote:
    > I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?


    I would strongly suggest picking up a good book on astrophotography,
    otherwise you will end up with
    mediocre results.
     
    Rich, Aug 3, 2007
    #7
  8. Craig Guest

    As others have said, there are various ways of doing this a T-adapter,
    eyepiece projection, Telephoto lens.

    If you use a telescope, you will need a good solid mount that tracks.

    You should be able to shoot the moon with a telephoto lens and tripod.
    Most shots will be in 1/60 - 1/125 range depending on the moon's phase.

    I wopuld suggest picking up the following books. they will help you
    understand all that is involved with the hobby.

    Digital SLR Astrophotography: by Michael A. Covington.

    "Introduction to Digital Astrophotography: Imaging the Universe with a
    Digital Camera" by Robert Reeves. He covers a ton of info from choosing
    equipment to image processing.
    http://www.optcorp.com/product.aspx?pid=105-258-259-261-7018


    http://www.optcorp.com/product.aspx?pid=105-258-259-261-9231
    How to Photograph the Moon and Planets with Your Digital Camera by Tony
    Buick - OPT Telescopes

    http://www.astropix.com/GADC/INTRO.HTM
    A Guide to Astrophotography with Digital SLR Cameras


    Then there is the post processing area which is a whole 'nother topic.

    --
    Remove My_Skin to E-mail me.


    wrote:

    > I bought a Nikon D80 and I want to take pictures of the moon, planets
    > and stars. Does anyone have any idea how I can use a telescope to take
    > such pics? What do I need to use a telescope instead of the lens (the
    > mount...etc)?
     
    Craig, Aug 3, 2007
    #8
  9. Guest

    thanks to all. I really appreciate your help. I have the Nikon
    18-200mm VR and i used it to take pictures of the moon in different
    phases and the results were actually pretty good.. not great but good
    enough.. and handheld believe it or not.. the VR helped for sure.. I
    am sure if i use a tripod i would get way better results as i would be
    able to lower the ISO and use a lower shutter speed. which would get
    more details and lower noise.

    >From what I've read I'm guessing the T mount would be the simplest,

    easiest and most efficient solution. I looked up T mount for Nikon on
    adorama and I found 2 of them. But now my question is would the T
    mount that I buy work with any telescope? Or do I also have to match
    the size of the eyepiece...etc. (I'm sorry I don't know much about
    telescopes) .. also what do u mean by "a telescope with an equatorial
    mount and motor drive".. links to actual products on adorama would me
    help a lot to understand the difference :) thanks.
     
    , Aug 4, 2007
    #9
  10. daba6 Guest

    On Aug 4, 10:06 am, wrote:
    > thanks to all. I really appreciate your help. I have the Nikon 18-200mm VR and i used it to take pictures of the moon in different
    > phases and the results were actually pretty good.. not great but good enough.. and handheld believe it or not.. the VR helped for sure.. I
    > am sure if i use a tripod i would get way better results as i would be able to lower the ISO and use a lower shutter speed. which would get
    > more details and lower noise.
    > From what I've read I'm guessing the T mount would be the simplest, easiest and most efficient solution. I looked up T mount for Nikon on
    > adorama and I found 2 of them. But now my question is would the T mount that I buy work with any telescope? Or do I also have to match
    > the size of the eyepiece...etc. (I'm sorry I don't know much about telescopes) ..
    > also what do u mean by "a telescope with an equatorial mount and motor drive".. links to actual products on adorama would me
    > help a lot to understand the difference :) thanks.


    Telescopes commonly have one of two differrent tube sizes for fitting
    eyepieces and accessories : 1.25 inch and 2 inch diameter. Depending
    on which your chosen telescope has will determine which version of T-
    mount to buy for best fit, although I'm sure you can actually get
    adaptors for fitting 1.25 " accessories into the 2" tube.

    Although one of the books mentioned in others' posts would go a long
    way to illustrating in better detail, an equatorial mount is one of
    the more common ways the telescope tube mounts onto the tripod /
    support. Its main benefit is that you can track and follow the
    movement of objects in the sky as the earth rotates more effectively.
    >From the side view you have a cradle holding the actual telescope ;

    the cradle is at the top of almost 'vertical' shaft which in turn is
    fitted at right-angle onto a more 'horizontal' shaft, which rises from
    the base part of the mount on the tripod. Actually, the vertical and
    horizontal shafts are at a bit of angle from true upright and level.
    Properly set up, they should relate to the latitude (degrees north /
    south) of your viewing location .
    Anyhow, the 'horizontal' shaft rotates about an axis called 'right
    ascension' which is a bit like the longitude (east / west) of space
    and the cradle on top of the 'vertical' shaft rotates about another
    axis called 'declination' which is sort of like the latitude of
    space
    There are other variants of the equatorial such as the 'fork'
    equatorial which are becoming more numerous and are generally used
    with larger size telescopes, paricularly those in major astronomical
    observatories .
    Usually, a good equatorial mount will have measuring ('setting')
    circles on each axis for you to accurately measure the exact right
    ascension and declination positions of the star objects you're looking
    at.

    The motor drive is often a recommended option for the sake of
    automatically driving the rotation of the equatorial mount to follow
    the stars - as opposed to you having to stand there and manually move
    the scope yourself ,which could be tiresome and inconsistent. Some of
    the better telescopes such as Meade and Celestron are supplied with a
    drive as part of the bundle.

    Sugeest you look for a specialised telescope and astronomical
    equipment supplier in addition to Adorama to view some examples of
    scopes and equatorial mounts to get a better idea of what they're
    like.
     
    daba6, Aug 4, 2007
    #10
  11. Ray Fischer Guest

    <> wrote:
    >I bought a Nikon D80 and I want to take pictures of the moon, planets
    >and stars. Does anyone have any idea how I can use a telescope to take
    >such pics? What do I need to use a telescope instead of the lens (the
    >mount...etc)?


    Most people's advice has not been very good. Here's my version.

    1) Yes you need a T-mount. They're cheap ($30) and you buy it for the
    camera, not the telescope, since once you get one it'll work with most
    decent telescopes. It basically just attaches a 1 1/4" tube to your
    camera and most telescopes have either a 1 1/4" or 2" hole in which to
    insert the tube. Fancier versions of this tube allow you to put an
    eyepiece inside for higher magnification. They're only a little more
    expensive.

    2) The weight of the camera will be an issue with a small scope. Make
    sure that any telescope you get has amount capable of supporting the
    weight or that the scope can take counterweights.

    3) Planets and the moon are fairly easy. You won't get anything like
    what you've seen in magazines, but you'll be able to get decent photos
    of Saturn's rings and Jupiters bands, and the like.

    4) The hardest (imo) job of astrophotography is focus. Few SLR
    focusing screens can handle really dim objects like stars and nebulae
    and trying to see if a dim star is in focus is next to impossible.
    There are gadgets avaible which make accurate focusing possible but
    they're not cheap ($200+).

    5) No, you don't _need_ an equatorial mount. Certainly not to start
    and maybe not ever. For exposures up to 2-3 minutes a common
    alt-azimuth mount will suffice, assuming that it's computer controlled
    and can track. You can stack images for fainter objects.

    6) Serious guys not only use a good equatorial mount, they also spend
    money on autoguiders which do the job of keeping the scope pointed at
    a star. No mount, no matter how good, will keep the scope pointed
    at a sky object for a half hour or more needed for really dim objects.
    But a good equatorial mount and a basic autoguider is a $1000
    investment.

    7) If you live in the city you will have to limit you photographs to
    brighter objects. For some nebulae you can get a filter which blocks
    most light except for the emissions of glowing nebulae.

    This is a hobby which can produce great images, but it's pretty hard
    and pretty expensive to do really well.

    --
    Ray Fischer
     
    Ray Fischer, Aug 6, 2007
    #11
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