Moon - 25th Feb 2008

In all her glory as she watches over us ... Taken at prime focus

1000mm FL @ F10. Your comments are always helpfull, thank you

Greetings Tony --

Really sharp photo. This evening in the photo critique forum there appeared someone's full moon over water photoshop effort here:

http://photo.net/photodb/photo?photo_id=7004157

...which ran sufficiently counter to my astronomical sensibilities that I had to respond, in order to motivate the photographer to pay more attention to the relative sun--moon locations in the sky, etc. In the context of that mini astronomy lesson, I found your image here, and took the liberty of "borrowing" it for cut+paste purposes to illustrate in the above thread an alternative (more astronomically realistic) moonrise over water scene.

I hope first of all that you don't mind, and secondly might even be amused to see your image warmed, shrunk, and pasted-in over the other photographer's photoshop-simulated ocean or lake reflections at moonrise. We're all here for fun and to learn from each other, yes ?

Again, excellent photo in terms of sharpness along the terminator. I'm curious how much more sharp/fine details are visible in the full-size Nikon D200 image (or a subset cropped from it at 100% scale factor), versus the reduced-size picture posted here?

Cheers,

--Jim

lol Jim, thank you :)

And No, I dont mind at all. As you say we are here to learn and share, if not then why bother?

THis image was taken when the moon was about 40 deg above moon rise, but the detail held out well. The following images are crops at 100%, 200% and 300% from the original.

And at 200%

And at 300%

No sharpening was applied to any of these, only a small amount of Levels. To be honest, even a very small amount of 'unsharp mask' made the images worse, as in grainy.

The 300% crop represents a printed image some 16 feet x 16 feet ... lol, not quite life size but pretty big!

For the record, the crator at the top centre of the 300% crop is 65 miles (88 km) across ... just so you have some scale :)

Spotting that same "the crator at the top centre" of the 300% crop in the full frame image, and taking 30-arcmin for moon's diameter, I estimate the crater at about 40-arcsec diameter ... which says your telescope -- and the atmosphere above your astrophotography/observing site -- is indeed delivering ~ arcsec resolution, not to mention resolution well-matched to your Nikon D-200's CCD pixel size. Again, most impressive!

Much less impressive is the 200% magnified crop attached below from an image of the crescent moon I snapped Monday night with my Nikon D200 and a Tokina RMC 500mm f/8 reflex mirror lens (going rate for these on eBay is about US$75.00, give or take). To my eye it looks noticeably softer than your 200% crop, and in arcsec units, my pixels are twice as large since my lens is 500mm compared to your 1000mm. (In my portfolio you can see how the Tokina 500mm telephoto performs when paired with a Nikon TC-200 2x teleconverter, giving 1000mm focal length -- but sad to say reduced image sharpness, viewed side-by-side with a 200% magnified crop of the Tokina 500mm telephoto used alone ...).

To do better than this, I guess I'll need to take out of the closet my 8-inch Celestron SCT, and see what that can deliver in front of the Nikon D-SLR. Stay tuned !