I've never tried HDR imaging before, but it occurred to me that the partial phase of the eclipse would be a great application for the technique. I'd taken exposures of 1/2 at ISO-1000, 1/8 at 400 and 1/60 at 400, to cover the range of illumination present; if repeating this, I'd use more images, with no more than 2 stops between them.
The software didn't seem to like being asked to combine these three quite different images, so after cropping all three to the same FOV, I added a thin rectangle towards the edge of the frame to give the software something consistent to hang on to, and this seemed to work. (It's also possible that I hadn't got exactly the same cropping in my first attempt, which is what fooled the software, but being unfamiliar with the finer points of HDR, I can't be sure.)
Images taken with a Canon 40D, through an ancient and none-too-flash 6-inch Newtonian, undriven.
This is well-executed despite the challenges! Definitely a more realistic image than my somewhat overcooked lunar eclipse HDR a few years back. Excellent work!
Thanks Jonathan. I had a look at your images, but don't know enough about HDR to know what produced that result. From what I've seen of the rash of HDR photos (normal, not astro) that appeared a few years ago, over-cooked meant too little contrast in the end result, and a completely unnatural result, but yours is quite different.
What software did you use for the HDR combo? I used my recently-upgraded PaintShop Pro X6 (I'm not a Photoshop man), but I don't know hoew that compares to other HDR packages.
Hi Duncan, I use Photomatix for combining the images. Most of the time via Exposure blending mode. I then move it to photoshop for final editing.
I think for that particular partial lunar eclipse, i used the Tone Mapping mode in Photomatix. I thought I may have overdone it because the right hand edges were overexposed unnaturally as an after effect of the blending of the images.
Since then, I've tried to go easy on the sliders and make sure that the final hdr image doesn't veer too far away from reality.
I think I downloaded a trial version of Photomatix a while back, but don't remember anything of using it. From my few tests with PSP, it seems to do an OK job. Tone mapping is something I have yet to look into; I'm always a few years behind the times!
In terms of image processing generally, there was a principle in colour printing that you knew when the colour correction was right, after you'd gone too far, and I find it useful to apply that principle to my digital manipulations. Mind you, sometimes 'going much too far' can produce a result that you wouldn't have intended or anticipated, but which can be interesting or useful.
