I had some fun with the 2004 Lunar Eclipse ... so weather permitting, I might have to drag the Big Green Guy out and see if he wants to take a bit outa the moon again! .. ;-)
cad3 wrote:
Hrm... I wonder which would be better?
The 40D w/ 200 x1.4 x1.4?
Or the 5D w/ 200 x2 x1.4?
Anyone have any thoughts?
Well they will have almost the same number of pixels on the moon since the 40D has 2x the pixel density of the 5D and acts like a 1.4x TC itself then. The 40D should look a bit better IMO, due to only using 2 1.4x TC's and avoiding a 2x TC. I don't think there'll be a lot in it, but I would be curious to see 100% crops.
sirimiri wrote:
Might I ask (someone will surely know)
What are the choppy edges along the edge of the moon? Is it a lens issue? Thanks....
That's aberration caused by turbulence in the earth's atmosphere. It's why they build optical telescopes at the top of high mountains where the air's thinner.
For anyone planning to shoot the lunar eclipse next week, remember that the moon will go from very bright to very dim and back over the course of the event. The exposures get long, and they test your technique and tripod for a long lens. You may end up in the 1/4 or 1/2 second area. Remote release, mirror lock up, and the most rigid tripod setup you can find are all key to good images when the moon is in total eclipse with a beautiful deep red glow.
On most lenses that have a tripod foot for mounting, the least rigid part of a setup can be how rigid the lens is held by the tripod foot. Be sure to tighten your clamping knob well to help with that problem. The mentioning of using a sandbag on the lens hood may be to help with that issue, because is will "bind up" the lens in the tripod foot ring even better.
Also, depending on focal length and exposure time, you get to the point where the moons movement due to earth rotation is enough to cause the image to loose sharpness, unless you are using an equatorial tracking mount. Using a rigid tripod mount, you will actually be able to see the direction of movement in the image with the longer exposures by noting which sides of the moon have more blur. As the moon darkens to require the longer exposures, your best images may come from setting your ISO much higher that you normally would for a normal moon shot. You will be trading off image sharpness with sensor noise, and may need some post processing to improve the noise.
Getting the right exposure can be tricky also. Depending on how much of your image is filled with the moon, you may have a hard time "seeing" the moon on your histogram. Expect it to be a small bump on the right, and if you are over exposing it may be off scale to the right. Be sure to have your mode set to show over exposed parts of the image as flashing on your review sceen, because that is a much easier way to judge if any part of the moon is over exposed. Bracket lots of exposures to get a better selection to choose from. If you are trying to combine other objects in the image with the moon, bracketing is even more important, and you may find that doing a post process combine of the moon at one exposure and the rest of the picture at another exposure is much more pleasing. Also, the atmospheric disturbances that show up vary some with time, so if you take more shots, you may find some much sharper than others.
