Poor quality of lunar images with 20D/C90

Discussion in 'Digital Photography' started by jess, Sep 24, 2005.

  1. jess

    jess Guest

    I have a relatively new DSLR and an old (~ 1980, black tube) Celestron
    C90. The other light I tried taking a picture of the full moon with
    the camera at prime focus (tripod, ASA 1600, 1/800, remote release
    after ~10 sec of MLU), and the results were reasonably well-exposed
    but very fuzzy (and noisy: maybe ISO 200 or 400 would be better). I
    was using an Olympus Varimagni right angle finder attached to the
    camera. This gives a 2.5x magnification of the viewfinder, and I got
    the focus as sharp as I could. The view through the 20D viewfinder is
    horrible, though . . . I wish the screen had at least a small spot of
    fine-grained matte. There's a picture at:

    http://home.comcast.net/~jgates777/Moon.html

    I thought that perhaps the 'scope was damaged or had deteriorated in
    some way, but visual observations (30mm Kellner) look very sharp. So,
    I have a few questions:

    1. Is it normal for lunar astrophotographs to have much lower
    resolution than visual images?
    2. Since the 'scope focuses "beyond infinity", it is very
    difficult to focus on the screen in a Canon 20D. Do you have any tips
    for manual focusing with a DSLR, or is it largely trial and error
    ("Jeff R." at sci.astro.amateur recommended a Hoffman mask)?
    3. The tripod I was using was an old, cheap Velbon (~$25 new) I
    bought for a video project, and is none too stable. If you touch the
    'scope at all the image dances all over the place. After some
    research, I've ordered a Bogen / Manfrotto 3246 with 488RC2 Midi
    Ballhead that will be used primary for daylight photography, but it
    hasn't arrived yet. Would you folks with experience expect this to be
    any better?

    I understand that the 'scope is not the greatest, and this was my first
    try at lunar imaging, but my images look nowhere near as good as those
    I've seen from similar setups. I don't expect miracles, but these
    pictures are pretty sad. Any suggestions?
     
    jess, Sep 24, 2005
    #1
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  2. jess

    dylan Guest

    Whats the f number of the scope ?.
    You should be able to expose the moon at approx f8, 1/250th with ISO 100.
    You are right focussing can be difficult !
     
    dylan, Sep 24, 2005
    #2
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  3. jess

    Ray Fischer Guest

    jess <> wrote:
    >I have a relatively new DSLR and an old (~ 1980, black tube) Celestron
    >C90.


    1200mm f13, in camera lens terminology. 90mm aperture Maksutov design.

    > The other light I tried taking a picture of the full moon with
    >the camera at prime focus (tripod, ASA 1600, 1/800, remote release
    >after ~10 sec of MLU),


    Try ISO 100 or 200.

    > and the results were reasonably well-exposed
    >but very fuzzy (and noisy: maybe ISO 200 or 400 would be better). I
    >was using an Olympus Varimagni right angle finder attached to the
    >camera. This gives a 2.5x magnification of the viewfinder, and I got
    >the focus as sharp as I could. The view through the 20D viewfinder is
    >horrible, though . . . I wish the screen had at least a small spot of
    >fine-grained matte.


    As you have discovered, good dSLRs really suck at astrophotography
    because it is so hard to get a decent focus.

    > There's a picture at:
    >
    >http://home.comcast.net/~jgates777/Moon.html


    It's actually not bad. The C90 isn't a big scope and it simply isn't
    possible to get tons of fine detail. With telescopes, aperture matters
    a lot.

    >I thought that perhaps the 'scope was damaged or had deteriorated in
    >some way, but visual observations (30mm Kellner) look very sharp.


    Your eye can compensate some for focusing errors.

    > So,
    >I have a few questions:
    >
    > 1. Is it normal for lunar astrophotographs to have much lower
    >resolution than visual images?


    The eye does a wonderful job of integrating images over time and
    building up detail. The camera doesn't. One technique used is to
    combine dozens of images into a much better composite.

    > 2. Since the 'scope focuses "beyond infinity", it is very
    >difficult to focus on the screen in a Canon 20D. Do you have any tips
    >for manual focusing with a DSLR, or is it largely trial and error
    >("Jeff R." at sci.astro.amateur recommended a Hoffman mask)?


    Unless you can replace the focusing screen, or use an electric focuser
    on the scope, what have is what you have.

    > 3. The tripod I was using was an old, cheap Velbon (~$25 new) I
    >bought for a video project, and is none too stable. If you touch the
    >'scope at all the image dances all over the place.


    Making it really hard to focus. (hint, hint)

    > After some
    >research, I've ordered a Bogen / Manfrotto 3246 with 488RC2 Midi
    >Ballhead that will be used primary for daylight photography, but it
    >hasn't arrived yet. Would you folks with experience expect this to be
    >any better?


    Don't know that tripod. The tripod I use on mine scope is pretty
    solid.

    >I understand that the 'scope is not the greatest,


    Don't knock it. It's a fine scope.

    > and this was my first
    >try at lunar imaging, but my images look nowhere near as good as those
    >I've seen from similar setups. I don't expect miracles, but these
    >pictures are pretty sad. Any suggestions?


    Don't take pictures of a full moon. It's boring. All the detail
    washes out. Try the crescent moon.

    --
    Ray Fischer
     
    Ray Fischer, Sep 24, 2005
    #3
  4. jess

    Jim Guest

    "jess" <> wrote in message
    news:...
    > 3. The tripod I was using was an old, cheap Velbon (~$25 new) I
    > bought for a video project, and is none too stable. If you touch the
    > 'scope at all the image dances all over the place.

    Why not get the tripod that Celestron sells for such a scope? It seems to
    me that you are trying to get good photographs with equipment that is
    totally inadequate (except for the scope that is).
    Jim
     
    Jim, Sep 24, 2005
    #4
  5. jess

    dylan Guest

    Do you use mirror lock to stop vibrations ?
     
    dylan, Sep 24, 2005
    #5
  6. jess

    Basiltoo Guest

    "jess" <> wrote in news:1127585123.145180.137920
    @o13g2000cwo.googlegroups.com:

    > I have a relatively new DSLR and an old (~ 1980, black tube) Celestron
    > C90. The other light I tried taking a picture of the full moon with
    > the camera at prime focus (tripod, ASA 1600, 1/800, remote release
    > after ~10 sec of MLU), and the results were reasonably well-exposed
    > but very fuzzy


    You might find this thread interesting:
    http://forums.dpreview.com/forums/read.asp?forum=1010&message=14611149

    --
    Regards,
    Baz
     
    Basiltoo, Sep 24, 2005
    #6
  7. In article <>,
    "jess" <> wrote:

    > I have a relatively new DSLR and an old (~ 1980, black tube) Celestron
    > C90. The other light I tried taking a picture of the full moon with
    > the camera at prime focus (tripod, ASA 1600, 1/800, remote release
    > after ~10 sec of MLU), and the results were reasonably well-exposed
    > but very fuzzy (and noisy: maybe ISO 200 or 400 would be better).


    Hey! I used to have a C80 when I was a kid! Tied it to a Pentax.

    There is no need for that fast of ASA. I used to shoot 200 ASA and as
    slow as 1/125 and get sharply exposed moon shots. That ASA speed is
    probably where most of the fuzziness is coming from. Yeah, no need to
    shoot at 1/800.

    Also, the exposure for a mostly full moon like that is the same for a
    sunny day (sunny/16).

    What kind of DSLR and what mode are you in? JPEG or RAW?

    look!
    http://www.weasner.com/etx/guests/guests_moon.html

    > I
    > was using an Olympus Varimagni right angle finder attached to the
    > camera. This gives a 2.5x magnification of the viewfinder, and I got
    > the focus as sharp as I could. The view through the 20D viewfinder is
    > horrible, though . . . I wish the screen had at least a small spot of
    > fine-grained matte. There's a picture at:
    >
    > http://home.comcast.net/~jgates777/Moon.html
    >
    > I thought that perhaps the 'scope was damaged or had deteriorated in
    > some way, but visual observations (30mm Kellner) look very sharp. So,
    > I have a few questions:
    >
    > 1. Is it normal for lunar astrophotographs to have much lower
    > resolution than visual images?
    > 2. Since the 'scope focuses "beyond infinity", it is very
    > difficult to focus on the screen in a Canon 20D. Do you have any tips
    > for manual focusing with a DSLR, or is it largely trial and error
    > ("Jeff R." at sci.astro.amateur recommended a Hoffman mask)?
    > 3. The tripod I was using was an old, cheap Velbon (~$25 new) I
    > bought for a video project, and is none too stable. If you touch the
    > 'scope at all the image dances all over the place. After some
    > research, I've ordered a Bogen / Manfrotto 3246 with 488RC2 Midi
    > Ballhead that will be used primary for daylight photography, but it
    > hasn't arrived yet. Would you folks with experience expect this to be
    > any better?
    >
    > I understand that the 'scope is not the greatest, and this was my first
    > try at lunar imaging, but my images look nowhere near as good as those
    > I've seen from similar setups. I don't expect miracles, but these
    > pictures are pretty sad. Any suggestions?





    --

    Photographs by Christian Bonanno
    http://christianbonanno.com/
     
    Christian Bonanno, Sep 24, 2005
    #7
  8. jess

    jess Guest

    Nominally it's about 1000mm f11, but I have read that the effective
    aperture is more like f12.5 (as Ray Fisher suggests below). I'd
    believe you about the exposure, but I read ISO 1600, 1/1800 from the
    EXIF data and if anything the image looks underexposed.
     
    jess, Sep 24, 2005
    #8
  9. jess

    jess Guest

    I understand that there is not a lot of aperture with the C90, but
    I've seen other C90 shots via afocal methods that are far better.
    The link that Basiltoo posted below, for example
    http://forums.dpreview.com/forums/read.asp?forum=1010&message=14611149
    shows what I would call very fine detail from such a small scope.
    Admittedly, it's not a full moon, and the shodw adds quite a bit of
    perceived detail. I'll try a less than full moon next time and play
    around with the ISO/exposure tradeoff. Perhaps the new tripod will
    help. Thanks for the comments and suggestions.
     
    jess, Sep 24, 2005
    #9
  10. jess

    jess Guest

    Well, I'm not really attempting to get into astrophotography with
    this sort of telescope. I just thought a moon shot would be
    interesting. Getting an astronomical tripod seems a bit of overkill
    unless I'm attempting guided exposures of planets and deep space
    objects. If I were going to do that, I'd probably figure out a way
    to spring for a telescope with at least 8" of aperture. But, as I
    said, I did spring for a substantially better tripod for terrestrial
    work, and hopefully that will help a bit.
     
    jess, Sep 24, 2005
    #10
  11. jess

    jess Guest

    Yes, I used MLU and a cable release. I waited for approximately 10
    seconds after MLU before tripping the shutter.
     
    jess, Sep 24, 2005
    #11
  12. jess

    jess Guest

    Yes, saw that the other night. In fact, that image is was prompted me
    to try a moon shot --- I wanted to see how well my (much older, well
    traveled) C90 could do. Not very well, it seems.
     
    jess, Sep 24, 2005
    #12
  13. jess

    Bob Guest

    On 24 Sep 2005 11:05:23 -0700, "jess" <> wrote:

    >I have a relatively new DSLR and an old (~ 1980, black tube) Celestron
    >C90. The other light I tried taking a picture of the full moon with
    >the camera at prime focus (tripod, ASA 1600, 1/800, remote release
    >after ~10 sec of MLU), and the results were reasonably well-exposed
    >but very fuzzy (and noisy: maybe ISO 200 or 400 would be better). I
    >was using an Olympus Varimagni right angle finder attached to the
    >camera. This gives a 2.5x magnification of the viewfinder, and I got
    >the focus as sharp as I could. The view through the 20D viewfinder is
    >horrible, though . . . I wish the screen had at least a small spot of
    >fine-grained matte. There's a picture at:
    >
    >http://home.comcast.net/~jgates777/Moon.html
    >
    >I thought that perhaps the 'scope was damaged or had deteriorated in
    >some way, but visual observations (30mm Kellner) look very sharp. So,
    >I have a few questions:
    >
    > 1. Is it normal for lunar astrophotographs to have much lower
    >resolution than visual images?
    > 2. Since the 'scope focuses "beyond infinity", it is very
    >difficult to focus on the screen in a Canon 20D. Do you have any tips
    >for manual focusing with a DSLR, or is it largely trial and error
    >("Jeff R." at sci.astro.amateur recommended a Hoffman mask)?
    > 3. The tripod I was using was an old, cheap Velbon (~$25 new) I
    >bought for a video project, and is none too stable. If you touch the
    >'scope at all the image dances all over the place. After some
    >research, I've ordered a Bogen / Manfrotto 3246 with 488RC2 Midi
    >Ballhead that will be used primary for daylight photography, but it
    >hasn't arrived yet. Would you folks with experience expect this to be
    >any better?
    >
    >I understand that the 'scope is not the greatest, and this was my first
    >try at lunar imaging, but my images look nowhere near as good as those
    >I've seen from similar setups. I don't expect miracles, but these
    >pictures are pretty sad. Any suggestions?


    Your picture is fuzzy, alright! Mine are a little bit better, but not by a
    lot... I just got a scope to use with my D70.... and yes its dam hard to focus!

    I was shooting at 1/250 sec, ISO 800. The scope is a 4" MAK-CAS 1300mm f/13.

    I was told that I would be better off with a scope with f/6 or so... maybe next
    year!

    Tripod is a Slik very heavy model (cost as much as the scope!) good for normal
    photography, but it too shakes the moon if you touch it! I use the IR remote.

    I'm going to try damping out vibration with an old coat or something and see if
    that helps.

    I will post a moon pic on alt.binaries.photos.original for you to see.
     
    Bob, Sep 24, 2005
    #13
  14. Was you tripod sitting on a deck or on solid ground? A deck may be
    suject to vibrations, although your shutter speed was quite high.

    I have a C90 (older, orange) that I have been waiting to use with my
    D70 to get some moon pictures. I say waiting because I have a
    restricted view from my house due to hills and trees and the moon
    hasn't been in position yet. Also coincidentally, I have been putting
    up with a shakey Veblon for years and just recently bought a Manfretto
    tripod. So far I have just tried to shoot some star trails with the
    camera and a lens, but had trouble at first until I moved the tripod
    off of the deck.
     
    john_doe_ph_d, Sep 25, 2005
    #14
  15. jess

    jess Guest

    No, I can't use a shaky foundation as an excuse: the tripod was
    sitting with legs and centerpost fully collapsed on a concrete
    driveway. I was, however, shooting over the top of my house because,
    like you, I am surrounded by obstructions (mostly 60' oak trees).
    There was not a substantial temperature differential between indoor and
    outdoor temperature at the time, although there was quite a bit of sun
    load on the attic during the day and there might have been some
    convection currents and turbulence above the roof.

    In reality, however, I think the main problem was focus. I've not
    used a D70, though I have a number of friends who own and absolutely
    love them. I hope for your sake that the Nikon has a better screen
    than the 20D. As I indicated above, I'll try focusing on a single
    star before trying the moon the next time. I'll also try to let the
    moon get higher in the sky (assuming the clouds ever break up).

    It's ironic in a way, but I used to shoot my Olympus OM-1 and OM-2
    cameras, and though the 20D would be a step up in quality and
    flexibility. In many ways it is, but I sure do miss that bright
    viewfinder and fine matte screen (when I needed it). Anyway, good luck
    with your moon shots. If mine ever get better I'll repost here and
    tell y'all how I did it. If they don't . . . well, there's always
    macro work and the grandkids!
     
    jess, Sep 25, 2005
    #15
  16. jess

    Charles Guest

    On 24 Sep 2005 21:13:46 -0700, "jess" <> wrote:

    >No, I can't use a shaky foundation as an excuse: the tripod was
    >sitting with legs and centerpost fully collapsed on a concrete
    >driveway. I was, however, shooting over the top of my house because,
    >like you, I am surrounded by obstructions (mostly 60' oak trees).
    >There was not a substantial temperature differential between indoor and
    >outdoor temperature at the time, although there was quite a bit of sun
    >load on the attic during the day and there might have been some
    >convection currents and turbulence above the roof.
    >
    >In reality, however, I think the main problem was focus. I've not
    >used a D70, though I have a number of friends who own and absolutely
    >love them. I hope for your sake that the Nikon has a better screen
    >than the 20D. As I indicated above, I'll try focusing on a single
    >star before trying the moon the next time. I'll also try to let the
    >moon get higher in the sky (assuming the clouds ever break up).
    >
    >It's ironic in a way, but I used to shoot my Olympus OM-1 and OM-2
    >cameras, and though the 20D would be a step up in quality and
    >flexibility. In many ways it is, but I sure do miss that bright
    >viewfinder and fine matte screen (when I needed it). Anyway, good luck
    >with your moon shots. If mine ever get better I'll repost here and
    >tell y'all how I did it. If they don't . . . well, there's always
    >macro work and the grandkids!



    why not post your message in alt.binaries.pictures.astro.

    There's some clever people there.
     
    Charles, Sep 25, 2005
    #16
  17. jess

    Rich Guest

    On 24 Sep 2005 15:01:18 -0700, "jess" <> wrote:

    >Well, I'm not really attempting to get into astrophotography with
    >this sort of telescope. I just thought a moon shot would be
    >interesting. Getting an astronomical tripod seems a bit of overkill
    >unless I'm attempting guided exposures of planets and deep space
    >objects. If I were going to do that, I'd probably figure out a way
    >to spring for a telescope with at least 8" of aperture. But, as I
    >said, I did spring for a substantially better tripod for terrestrial
    >work, and hopefully that will help a bit.


    You'll get 100x better shots by simply buying a Philips Tuocam Pro
    webcam, stacking about 200-800 video images (30 per second)
    with software like Registax and letting it process the image for
    you. DSLRs are NOT a good solution for lunar or planetary
    photography.
    -Rich
     
    Rich, Sep 25, 2005
    #17
  18. jess

    dylan Guest

    "jess" <> wrote in message
    news:...
    > Nominally it's about 1000mm f11, but I have read that the effective
    > aperture is more like f12.5 (as Ray Fisher suggests below). I'd
    > believe you about the exposure, but I read ISO 1600, 1/1800 from the
    > EXIF data and if anything the image looks underexposed.
    >


    1/1800 @ 1600 ISO
    = 1/900 @ 800 ISO
    =1/450 @ 400 ISO
    =1/225 @ 200 ISO
    =1/112 @ 100 ISO

    from my figures of 1/250 @ f8 using 100 ISO
    your f number = approx f 16, so 12.5 sounds about right.

    try setting 100 or 200 ISO for better quality.

    and use the mirror lock facility in the camera.

    Cheers
     
    dylan, Sep 25, 2005
    #18
  19. jess wrote:

    > As I indicated above, I'll try focusing on a single
    > star before trying the moon the next time. I'll also try to let the
    > moon get higher in the sky (assuming the clouds ever break up).
    >

    If you think focusing on the moon is hard, wait until you try to focus
    on a tiny star. I was thinking of doing the opposite: waiting until the
    moon was in view so I could focus at it and then move over to also do
    some star trails.
     
    john_doe_ph_d, Sep 25, 2005
    #19
  20. jess

    dylan Guest


    > from my figures of 1/250 @ f8 using 100 ISO
    > your f number = approx f 16


    D'oh ! try f11, makes your f12.5 nearer.
     
    dylan, Sep 25, 2005
    #20
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