Photographing the Moon--Help!
Paul Ciszek
somewhat detailed picture of the full moon with my new camera. I am a
total noob at this sort of thing, and looking for advice. Here are some
of the details:
The camera is a Lumix FZ-35 with a 1.7x teleconverter. In 35mm camera
terms, that is supposed to translate to an 826mm focal length at maximum
zoom. I figure the full moon will be about 800 pixels wide on my
sensor; you can check my math at the end of this post. I tested the
camera at maxium zoom with the teleconverter indoors (i.e., well lit but
not sunlit) and the pictures seem crisp enough when viewed 1:1 on a
computer monitor, so I am fairly confident that the optics live up to
the resolution of the sensor.
The maximum aperture at maximum zoom is, I think, f/4.4; I do not know
if the teleconverter limits this further. I do not have a tracking
mount, only a tripod. Again, by my amateur figuring, I think that means
I should limit the exposure time to a half-second, preferably less, if I
want to avoid blurring the image by more than a few pixels. The so-
called "film speed" is adjustable. I can set the parameters manually,
let the camera do it automatically, or ask the camera to prioritize a
parameter.
So, am I insane to even try this? What would be my best course of
action, short of getting a real telescope? I suspect that where I
am going to come up short is light-gathering ability; what film speed
would one need to get a decent exposure of the full moon in one half
second at f/4.4?
OK, the math I promised: According to the manufacturer, the focal
length of the zoom lens goes from 4.8 to 86.4mm; the teleconverter is
supposed to multiply that by a factor of 1.7 for an effective focal
length of 147mm at maximum zoom. At 29 arc-minutes, I think that makes
the image of the moon on the sensor 1.24mm in diameter; is that how it
works? The sensor is 6.13mm and 4000 pixels wide, so 1.24mm = about 800
pixels.
--
Please reply to: | "Any sufficiently advanced incompetence is
pciszek at panix dot com | indistinguishable from malice."
Autoreply is disabled |
Martin Brown
> In a couple of weeks when the moon is full, I want to see if I can get a
> somewhat detailed picture of the full moon with my new camera. I am a
Try it sooner - you get sharper detail when the terminator is in full
view. A full moon tends to look a bit disappointing and lacking in
contrast. Try that as well - but don't expect too much.
Ideally you want something like 2000mm effective focal length to get a
full frame moon image (thats a bit on the tight side with no margin for
error) and anything over 1000mm should give something plausible.
> total noob at this sort of thing, and looking for advice. Here are some
> of the details:
>
> The camera is a Lumix FZ-35 with a 1.7x teleconverter. In 35mm camera
> terms, that is supposed to translate to an 826mm focal length at maximum
> zoom. I figure the full moon will be about 800 pixels wide on my
> sensor; you can check my math at the end of this post. I tested the
> camera at maxium zoom with the teleconverter indoors (i.e., well lit but
> not sunlit) and the pictures seem crisp enough when viewed 1:1 on a
> computer monitor, so I am fairly confident that the optics live up to
> the resolution of the sensor.
>
> The maximum aperture at maximum zoom is, I think, f/4.4; I do not know
> if the teleconverter limits this further. I do not have a tracking
> mount, only a tripod. Again, by my amateur figuring, I think that means
> I should limit the exposure time to a half-second, preferably less, if I
> want to avoid blurring the image by more than a few pixels. The so-
> called "film speed" is adjustable. I can set the parameters manually,
> let the camera do it automatically, or ask the camera to prioritize a
> parameter.
No film is wasted in a digital camera. Bracket the exposures extensively
- when the moon is only covering a part of the frame autoexposure tends
to over expose. The exposure should be roughly what you would use for a
tarmac road on a bright sunny day (which is what it is on the moon).
>
> So, am I insane to even try this? What would be my best course of
> action, short of getting a real telescope? I suspect that where I
> am going to come up short is light-gathering ability; what film speed
> would one need to get a decent exposure of the full moon in one half
> second at f/4.4?
You would also be much better off photographing first quarter moon or
even the very pretty crescent moon. Last nights young crescent mooon was
exceptionally pretty hanging in the sky here.
>
> OK, the math I promised: According to the manufacturer, the focal
> length of the zoom lens goes from 4.8 to 86.4mm; the teleconverter is
> supposed to multiply that by a factor of 1.7 for an effective focal
> length of 147mm at maximum zoom. At 29 arc-minutes, I think that makes
> the image of the moon on the sensor 1.24mm in diameter; is that how it
> works? The sensor is 6.13mm and 4000 pixels wide, so 1.24mm = about 800
> pixels.
It will work best on a tripod with the timer used for shutter release to
avoid vibration from pressing the button. Otherwise your numbers look
ok. And you can preview afterwards to see what you have captured.
My guess is you will tend to overexpose at first and that will burn out
the highlights and lose detail.
Regards,
Martin Brown
David Staup
"Paul Ciszek" <nos...@nospam.com> wrote in message
news:hj3enf$me2$1...@reader1.panix.com...
you're looking at very short exposures ....1/250 or less depending on the
sensitivity you select....the tripod is all you need ...use the delay timer
as suggested to avoid vibrations.... bracket exposure until you get it right
(the right exposure will be darker than you want for your final image) then
take multiple exposures and use Registax (freeware) to "stack" the group
and process to obtain a final image with a better signal/noise ratio
checkout the yahoo group "digital astro" for more help as you move up from
total nube...
David Staup
one more thing... short of getting a scope you are better off buying a used
canon DSLR (300 or 350D's) are a good - relatively inexpensive way to start
and used lenses are also available check out ASTROMART and ebay. that way
when you do get a telescope (and decent mount) you can move up to prime
focus (using the telescope as the only lens(es) ) with the right adapter....
Chris L Peterson
Ciszek) wrote:
> I suspect that where I
>am going to come up short is light-gathering ability; what film speed
>would one need to get a decent exposure of the full moon in one half
>second at f/4.4?
Aim for a low ISO setting- 100 or 200 ought to do well with the Moon. As
you go to higher sensitivities, the noise increases. You probably won't
be light limited, even with the relatively fast exposures required to
prevent motion blur (certainly much faster than tenths of seconds).
One thing not mentioned by others: your camera has a RAW image mode. Use
it. I don't know what the actual dynamic range of the camera is, but it
is probably more than the 8-bits you get from JPEG, and the RAW mode
should make that extra depth available. It will also avoid JPEG
artifacts, and give images more suitable for later stacking.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
canopus56
> In a couple of weeks when the moon is full, I want to see if I can get a
The Moon is about 1/2 deg in diameter - the same as the Sun. Hold
your arm straight out and raise an index finger. With your arm
extended, your fingertip covers about 1 deg. After sunset, locate a
street lamp or other lit terresterial object that is about the same
size. That will give you something to practice focusing and scale
on. As others have noted, expect exposure times on the order of
1/250th of a second _or less_. The following exposure calculator may
be of help making an initial guess:
http://www.rphotoz.com/astrophoto/expcalcs.html
For fixed-tripod mounted photography, you are limited to very short
exposures (~ 0.1 secs or less) or expect to start seeing star and
lunar feature drift in your images.
Clear Skies - canopus56
canopus56
month near 1-29 1-30, the Moon will be near perigee and will be one of
the apparent largest full Moon's of the year. If you have one for
your camera, consider adding any kind of neutral density filter, e.g.
- one used on particularly bright sunny days to reduce glare. Clear
Skies - canopus56 .
Chris L Peterson
How does a ND filter reduce glare? It seems like a poor choice for an
unguided lunar image, where you are likely to want as fast an exposure
as possible to reduce motion blur and shutter vibration. Adding a ND
filter just provides another surface to produce some internal
reflections, and requires a longer exposure time.
canopus56
> On Tue, 19 Jan 2010 16:23:14 -0800 (PST), canopus56
>
The full Moon is so bright, it can be beyond the ability of some DSLR
camera's to conveniently cope with in terms of f/ stop and shutter
speed. Any kind of filter that reduces the amount of light entering
the camera can get the exposure and f/stop values into a better
workable range. Although the original poster is not working with a
traditional telescopic setup, that is in part why most of the best
telescopic imagers use I and R filters - there is too much light that
the shutter speed of an astronomy camera is overexposed below even
1/2500 sec. Clear Skies - canopus56
Anthony Ayiomamitis
Paul,
Here is a sample result taken with a focal length of 1200mm using ISO
100 and 1/125 sec for an exposure: http://www.perseus.gr/Astro-Lunar-Scenes-Perigee-2008.htm
... similar to your situation, this was also relatively large perigee
moon.
Anthony.
Chris L Peterson
<cano...@yahoo.com> wrote:
>The full Moon is so bright, it can be beyond the ability of some DSLR
>camera's to conveniently cope with in terms of f/ stop and shutter
>speed.
It's about the same brightness as freshly laid black asphalt. I hope not
many cameras are unable to deal with that!
William Hamblen
The full Moon is only a sunlit landscape. If a consumer digital
camera (which is what this thread started with) can take daylight
pictures it can take a picture of the Moon. The Moon has a
reflectivity like an asphalt road. Assuming ISO 100, f/16 at 1/125
would work, or f/5.6 at 1/1000, etc. Bracket widely.
Bud