Assignment #41: Half-Moon
Nikolai
Registered Users Posts: 19,035 Major grins
Given my history with the Earth biggest satellite, I'm sure you all knew this one was coming.:wink Time is about right, weather is nice (at least here in SoCal:-), so why don't we all take a shot or two at our celestial neighbour?
This week's target is moon, more specifically half-moon (in case you're catching up - try to select a time of month when the moon is close to it's half, no matter which: growing or dying).
Some hints...
Many novice moonshooters bend over backwards trying to get a decent moon shot and wonder why it is not happening. Others memorize some magic numbers and try to convince themselves and the others that this is some arcane lore which should be followed verbatim.
The things are simple. Remember "Sunny 16"? Having an ISO100 film and a sunny day, set your aperture to f/16, your shutter speed to 1/100s - and you get a perfect exposure. For those who lack clear blue sky most time of the year, there is "Cloudy 8" - same thing, just open your aperture.
No the moon is a bright sunlit object. Of course, its albedo (~reflection coefficient, but don't quote me on this in your optics class) is only 12%, but it has some other quirks to it, so pretty much "Cloudy 8" works wonders. Or you can step it up a bit and operate with f/10 or f/11.
Now that we have figured out the exposure, how about the other tricks? Forums are full with the advices on MLU, tripods, etc. Well, let's get to it.
First of all, at these shutter speeds there is absolutely no need for MLU. Moreover, you can definitely open your aperture up a bit (say to f/8 or even f/5.6, depending on your lens) and use even faster shutter speeds.
Tripod.. well, it depends. If you have an IS lens - you don't really need it. If you don't - you probably do. Decent size moon shots (those you can print at least 4x6) start at 400mm (yes, you do need a long lens!), and holding it up requires the hand of steel - or, better, a trio of aluminum or CF legs:-)
So, do you think you can take something like this?
One image per entry please. Add some description (how you did it, etc.), and some basic exif info (aperture, iso, shutter speed).
As usual, fresh pictures only (meaning: taken AFTER you have become aware pf this assignment), moderate post-processing.
For the rest of the basic rules and index please check out this sticky.
Let's get some half-moon!
This week's target is moon, more specifically half-moon (in case you're catching up - try to select a time of month when the moon is close to it's half, no matter which: growing or dying).
Some hints...
Many novice moonshooters bend over backwards trying to get a decent moon shot and wonder why it is not happening. Others memorize some magic numbers and try to convince themselves and the others that this is some arcane lore which should be followed verbatim.
The things are simple. Remember "Sunny 16"? Having an ISO100 film and a sunny day, set your aperture to f/16, your shutter speed to 1/100s - and you get a perfect exposure. For those who lack clear blue sky most time of the year, there is "Cloudy 8" - same thing, just open your aperture.
No the moon is a bright sunlit object. Of course, its albedo (~reflection coefficient, but don't quote me on this in your optics class) is only 12%, but it has some other quirks to it, so pretty much "Cloudy 8" works wonders. Or you can step it up a bit and operate with f/10 or f/11.
Now that we have figured out the exposure, how about the other tricks? Forums are full with the advices on MLU, tripods, etc. Well, let's get to it.
First of all, at these shutter speeds there is absolutely no need for MLU. Moreover, you can definitely open your aperture up a bit (say to f/8 or even f/5.6, depending on your lens) and use even faster shutter speeds.
Tripod.. well, it depends. If you have an IS lens - you don't really need it. If you don't - you probably do. Decent size moon shots (those you can print at least 4x6) start at 400mm (yes, you do need a long lens!), and holding it up requires the hand of steel - or, better, a trio of aluminum or CF legs:-)
So, do you think you can take something like this?
One image per entry please. Add some description (how you did it, etc.), and some basic exif info (aperture, iso, shutter speed).
As usual, fresh pictures only (meaning: taken AFTER you have become aware pf this assignment), moderate post-processing.
For the rest of the basic rules and index please check out this sticky.
Let's get some half-moon!
"May the f/stop be with you!"
0
Comments
Canon 300D 1/250s f/5.6 ISO 100 300mm
Thank you, nice entry!
Moon over SoCal, Fri June 22 2007:
Canon 30D + ED 100-400L @ 400mm + TCx1.4 (pins taped)
handheld, full manual (including manual focus), ISO 100, f/8.0, 1/100s, IS on
Maybe someday I'll buy something longer again
This one handheld with 100-300/5.6L on 10D
XTi, G9, 16-35/2.8L, 100-300USM, 70-200/4L, 19-35, 580EX II, CP-E3, 500/8 ...
DSC-R1, HFL-F32X ... ; AG-DVX100B and stuff ... (I like this 10 years old signature :^)
Uhm, how about the "freshness" rule?
XTi, G9, 16-35/2.8L, 100-300USM, 70-200/4L, 19-35, 580EX II, CP-E3, 500/8 ...
DSC-R1, HFL-F32X ... ; AG-DVX100B and stuff ... (I like this 10 years old signature :^)
Here are two versions of the harf moon, the way it is seen in Portugal.
The first picture was shot this afternoon at the beach when I was shooting kite-board. Later, you will be able to see some of these photos.
The shot at night is only half an hour old ...:D
How about this ?
Handheld Canon 300D 1/320s f/8 ISO 100 300mm
Original
Cropped
Nikon D2x - 70-200 F/2.8 w/TC20EII (600mm equiv) ISO 100 F/11 1/60s (using tripod)
Thank you, nice entries (I laughed a lot on 1st one:-)
Even with 135mm, you don't need to have all that negative space around. Besides, cropping it to 100% would make your final immage bigger:-)
Another thing - wait until dark. Moon is a shy person, she only likes to be photographed in her own light:-)
Not bad at all. I'd wait a bit more for darkness and played with sharpening (Hiraloam in PS or sharpening in ACR4.0)
Nice shooting!
I personally think the 100% crop is the way to go, nobody needs that much of a black void anyway.
BTW, I kinda disagree with you on your focal length math. 200mm and TC2 cal only bring you up to 400mm. Crop factor, while making a subject realtively larger in the frame, does not in fact, change the optical path. Once you crop it to 100%, you'd get the same size image from FF and APC sensors (provided their resolution is the same in terms of sensels per square inch).
hi all I lurk mostly these days, but I thought I'd share some "math" on shooting the Moon. Some years ago now (using a film SLR) I did astrophotography and taught a lab on it for undergrads in the astronomy department. I get most of my info from a book called Astrophotography for the Amateur by Michael Covington. I believe the latest edition has info on digital SLRs...everything I quote below is for film. So...some minor tweaking.
1 - when you use a telephoto to photograph the Moon, know that the more you zoom, the more the "air turbulence" (think heat rising off a highway in waves), light pollution, environmental pollution, and 'position of the moon' affect the end result. Air turbulence gives a 'wavy' effect, mostly seen in small telescopes...it'll blur your image. The less atmosphere you look through the better...so get the Moon when it is almost overhead. Shooting the Moon close to the horizon you are looking through more "crap" that gets in the way and makes any colors off, gives haze, or makes a blurry image.
2 - cable release and tripod of course Though I know some of you are hand holding, that's fine when backed off, but for uber-zoom images you really get a better result with a tripod and cable release (or timer). If you can lock your mirror up, all the better. A little shake goes a long way.
3 - the "math" --- how long of an exposure can you take without the brighter/whiter areas blowing out?
The formula:
t (in seconds) = f^2/SB
t = exposure time
f = f-ratio
S = film speed in ISO
B = brightness of object being photographed (7 for thin crescent, 16 for wider crescent, 32 for half moon, 70 for gibbous moon, 180 for full moon)
The book I have recommends a telephoto lens set to f/5.6 or f/8 for "sharpness"
There's another formuls too: Longest practical exposure (as to not get motion of the Earth's spin or Moon orbit)
longest exposure (in s) = 250/F
F = focal length in mm
The more zoomed in you are, the faster the Moon will blur as you are zoomed into more 'motion'. The Moon moves quite fast...it's near the celestial equator, far away from the slower spinning sky near the North Star Polaris (north pole projected out into space)
4 - Bracket! Do it in various ways to find that 'perfect shot'. Use the above formula and find out what the best exposure is for 100, 400, 800 speed ISO settings. Keep the f-ratio the same. Then, for each ISO, go about 10 paces to underexposed and 10 paces to overexposed. For each setting (say f/8, ISO 400, 1/250s) do 3-5 shots. Yup, that's a lot of images! But...taking a few shots of the same settings can help with atmospheric effects. There's always that 'split second of clarity', maybe you can hit it. You don't process ALL of those b/c you'll easily be able to see straight off the images that were way underexposed and the ones that were blown out.
5 - Before EXIF I had to journal all this info with each photo. What you can do after you process everything in Photoshop is to make a visual record/collage of the settings for each photo and how it turned out. Then next time you go out ,you'll have your notes and know a good place to start. This actually was one of the lab assignments I'd do with students...some 100 images they had to pour through with different settings through all the phases of the Moon we could capture on film...though we didn't change the f-ratio (our telescopes were f/10) and we didn't change the film speed (ISO 400).
HAVE FUN I tried to get some moon shots last night after a star party and it didn't go so well. The air turbulence was really bad. I'll process and post though in a few days
Adrienne
Thank you a lot for your sharing, much appreciated!
I only based 600mm on the 200mm, 2x teleconverter and the 1.5x factor for the D2x sensor. The exif data also refers to it as 600mm.
hi all
Here's my try from last night with my Rebel XT hooked up to the telescope via T-Adapter. No eyepieces, no lenses, just the 8" mirror on the telescope. It works out to be f/10. This was on the 400 ISO setting and the best shot came out at 1/250s. I did a variety of focusing just in case my eyes were lying to me I still got some blur, but Photoshop fixed it up nice w/o over-doing it (fine line...). The air turbulence was super bad last night (you can see the image shimmer when looking through an eyepiece) so considering this is a good catch.
2 versions: Version A is just regular contrast, curves, sharpening. Nothing major. Version B used the Image > Adjustments > Shadow Highlight (PS CS2). I played for an hour with all the sliders!
What I like better about Version B is that there is more detail along the terminator and slightly past it. This matches more to 'what the eye sees' when looking through the telescope w/ a 40mm eyepiece. There were some fabulous features past the terminator, but it's hard to catch them without blowing out the brighter 'right side' of the Moon. The shadow highlight is a good little tool for the Moon shots, brings out some of the craters...
I'm torn as to which one I like more - slight differences only. It's hard to get the detail along the terminator you want, whilst not blowing out Stavinus (lower right white highland/crater area).
Labeled Moon map:
http://membres.lycos.fr/astrolimagne/dossier2.html
I actually like a full Moon or 3rd quarter better as to get Tycho, Kepler and Copernicus craters. If you capture it right you can get the whole ejecta blanket lines of Tycho going all the way up/across the face of the Moon
Version A:
Version B with Shadow/Higlight tool:
Cheers!
Adrienne
thank you for your entry!
Is it 100% crop? If it is, I'm purely amazed how war "conventional" optics (the one I use) stepped ahead of what's supposed to be the dedicated "astronomical" devices...
Thank you!
1) too much negative space. We're shooting moon, not the skies
2) 100% crop usually looks best
3) why shoot at dusk when you have the whole night?
right-o --- no crop at all
That's what an 8" Schmidt-Cassegrain telescope will getcha, with no eyepieces I had to finagle the camera around to get it all in. So -- I wouldn't even be able to get a full moon via telescope into my camera without eyepieces in the T-Adapter.
With a 40mm eyepiece inside the T-Adapter one can get the whole moon. I've photographed using a 15mm eyepiece and you get nice and up close with some of the lunar features. Then you've really got to experiment with the camera settings and possibly polarizing filters on the open end of the telescope (but those are DARN expensive!)
I prefer to actually crop Moon images like the whole Moon is there...so no tight cropping on the unlit side.
If you had good enough sky, you can get Earthshine on the unlit portion, seeing the whole Moon. That's from sunlight reflecting off the Earth's oceans back out into space where the Moon catches it and reflects it back to Earth.
Glad to finally delurk,
Adrienne
P.S. I just realized I broke the 1 image per entry rule Whoopsie! I do still want to leave it though to show the subtle difference in the Shadow/Highlight tool since (to me) it made a significant difference and closer to "what the eye sees" along that terminator line. Is ok?
I did finally figure out that matrix metering was not my friend. It kept blowing out the moon in an attempt to add shadow detail to everything else. Or something. Turned it to spot metering and things got a lot better.
Also, you apparently can't autofocus on the moon. It's too far away. Had to set 'er to manual focus.
1/200 second, F/8.0, ISO 200, 200mm (300mm equivelant), Pentax k100d.
While I agree that focusing on the moon is no easy business, apparently it depends on the camera. I use AF constantly on my Canon 30D, if not directly for focusing then at least for focus confirmation. Yes, spot metering helps alot.
Your image seems rather soft indeed :-( :cry I remember I had similar problem with smaller cameras/lenses though, so it may be your gear fault, not your own...
I might try again tonight with a tad faster shutter speed. Of course, my wife came out last night hopping mad --she thought I was trying to peep on the neighbors -- why else have a telephoto zoom out that late at night?
As to the autofocus -- it seemed to work ok in the front yard, but not in the back. I'm guessing there wasn't enough light and/or other visible objects around for the AF to work properly. No big deal, as the distance from me to the moon is a known quantity to manually focus on.
6-22-07
ISO 400
1/640
f5.6
Auto WB
70-200mm
6-22-7
ISO 400
1/250
f6.3
Flash WB
70-200
one day I'll be able to afford a real telescopic lens for this...
wish I had my 100-400 still.
dak.smugmug.com
Thank you!
But here it is...