Moon Slice

--Lannie

Hi Lannie,

I always enjoy a good lunar image. This is no exception.

Well done.

Question, since a 600mm focal length provides an  image size of less than 6mm, then did you crop and enlarge the image or did you use a teleconverter ?

Either way, the Canon 5D sensor is large enough to image the entire lunar disc onto its full frame sensor.

The full lunar disc shot that I sent to you at 2200mm fit nicely onto my Full frame DSLR (barley).

Best Regards,  Mike

Hi, Mile.  No teleconverter was used, but the image was not large in the frame, which was mostly empty sky.  I did crop it and resize it, although it might well be a 100% crop.  I did this several years ago and do not remember.  I know that I would not have resized it bigger than that.

This was shot in the afternoon when the moon was almost at its highest point for the day.  The sky was blue, and so the image was desaturated and contrast was added to darken the sky.  Very little sharpening was used--probably unsharp mask at 50%, since I am typically conservative about sharpening.

Since this was shot with the 12-megapixel 5D rather than the 21-megapixel 5D II, I am sure that I could have gotten better resolution at this size with my present 5D II.

--Lannie

Hi Lannie,

You did a very good job with the daytime moon.

Sometimes, I image most all the planets, moon, Sun, and some stars in the daytime using telescopes. The biggest issue is the atmospheric steadiness. It is often several times worse than at night because of the warmer air, ground radiation, etc. that effects the over all resolution.

The use of a 21 mega pixel camera would improve the final image, but it would be best realized by an early evening or night time session. Of coarse, not all nights are steady either.

The Nikkor 600mm F/4 is an excellent optic, and with a good 2X teleconverter can often keep up with telescopes for imaging the moon.

Best Regards,  Mike

Thanks, Mike.  I didn't really think too much about ground heating as a factor, but that makes sense during the afternoon.  I have certainly seen evidence of it  at night with higher telescope magnifications, especially of planetary objects--or splitting double stars.  "Good viewing" through a telescope is typically such an ephemeral thing, often changing within the space of a fraction of a second.  I do not typically think of it as being a problem with bright, close objects, such as the moon, but I guess that it could.

As for the 2x TC from Nikon, I have it but have not used it.  I wold probably have to tape over the contacts to get it to work with my Canons.

I am really impressed by the new posting you have put up.  This is awesome:

http://photo.net/photodb/photo?photo_id=13502792

I have wanted to do some closeups of the moon, as well as the planets, but I do not have the means to do it.  Right now the only scope I have is the Orion 80 ED, which I believe has an f/7 objective.  One thing that I have never gotten used to in astrophotography is that the magnification is a function of the objective lens, not its focal length divided by the focal length of the eye-piece, as in regular viewing.  I have never owned a large scope, nor even seen through one.

What I would really love to do is some work with nebulae, which I always considered beyond the reach of an 80mm refractor.  Howard Cox has done a pretty good job with the same small refractor that I have by stacking a series of shorter exposures.  Here is his take of M31 in Andromeda:

http://photo.net/photodb/photo.tcl?photo_id=5145424

He used the Losmandy G11 mount.  He has done some real deep space work as well--as if M31 were not far enough away.

Of course, one needs a good mount to get those results.  I don't have a good mount, and my old Celestron drive (bought second hand) vibrates too much to even bother to try.

--Lannie

Hi Lannie,

Interesting that you mention imaging deep space subjects like nebulae, star clusters and galaxies.

Your Nikkor 600mm F/4 used at F/4 is an outstanding lens for such work !

You will need a good equatorial tracking mount, but it does not have to be a large one since the Nikkor 600mm is relatively short .

With a Canon 5D or Canon 5D Mark II , set to ISO 800 or ISO1600, good results can be made in short exposures of less than 2 minutes. A darker sky location is best.

If you use a Canon teleconverter, then yes, tape will be required such that the Canon camera does not furnish an error warning. However, I often use my Canon teleconverters just slightly less then fully engaged and the error is avoided when I am using Nikkors or other lens with the converter. I do not do this for regularly , but I have not ever had the converter come off the Canon body.

Best Regards,  Mike

Mike, I can't afford a good mount right now, but, on the assumption that someday I might be able to, what would be a good mount for a small scope or a large telephone lens such as the Nikon 600 f/4?

--Lannie