Been some time, but here is the moon.

[Catanonia]

Decided to give the stars, nebula and galaxies a break and hit the moon with the SkyWatcher ED120 Pro and my new EOS 1000D

Took about 60 shots and stacked them with Registax to produce the following image.

[newf with a rebel]

Decided to give the stars, nebula and galaxies a break and hit the moon with the SkyWatcher ED120 Pro and my new EOS 1000D

Took about 60 shots and stacked them with Registax to produce the following image.
awesome shot . what type of lens were you using and the settings?

[Balliolman]

Sure is the Moon and a good shot of it too! :)

[Catanonia]

Lense is a telescope.

See here http://www.firstlightoptics.com/proddetail.php?prod=pro120ed2ota

[Fast Guy]

Can I ask why you needed to stack 60pictures to get that shot? I've seen similar (to my untrained eye) taken with one shot at 1/1000th.

(I'm not trying to knock you, I'm just curious)

[Catanonia]

Can I ask why you needed to stack 60pictures to get that shot? I've seen similar (to my untrained eye) taken with one shot at 1/1000th.

(I'm not trying to knock you, I'm just curious)

Not a silly question at all, quite a good one.


Bring out more of the fainter detail that a longer exposure would burn out the rest of the moon.

[Bernoulli]

Can I ask why you needed to stack 60pictures to get that shot? I've seen similar (to my untrained eye) taken with one shot at 1/1000th.


I want to weigh in on this, since I've done a lot of stacking Moon shots over the years. There are two reasons to stack: decrease noise and/or increase dynamic range (HDR). "Noise" comes in two varieties, sensor noise and distortion due to atmospheric tubrulent. Stacking decreases both of these.

For Moon shots taken at focal lengths under about 1000 mm, at low ISO, and fairly high in the sky, there is little to be gained by stacking to decrease noise. But, on the other hand, it's easy and doesn't take very long. When I shoot at over a couple of thousand mm, stacking starts to work wonders. I use CS4 and stack like this:

File -> Scripts -> Statistics
Then stack using "Mean".

At low magnifications, < 1000 mm, atmospheric turbulence is very small against the scale of the image and it rarely shows up in the picture. Luminance and chromatic noise from the sensor also isn't much of a problem because you're averaging a large number of pixels together to get a full disk image. So when I'm shooting at 900 mm (on my 100 mm f/9 apocrhomactic refractor) I no longer even bother to stack. But when I'm at 3000 mm I'll shoot at least a dozen identical exposure and stack them. The improvement is very noticeable.

I've experimented with stacking for HDR but never got results that I liked, but there's plenty there I haven't tried yet.

So that's my experience with stacking Moon shots.

[Catanonia]

mmmm interesting Rick. Might look at the stack and an original picture if I get time and see if any difference to be seen.

Plan tonight is to add a 3x barlow to the 900mm, so stacking will be done on them and goes with your experience too.

Do you find that adding stacks, actually brings out the fainter details of the moon without over exposing other areas ?

[Bernoulli]

Catanonia - I was just thinking about that question. I think the answer is no and let me see if this makes sense.

When you shoot deep sky, as you well know, you're trying to pull faint objects out of noise. The noise is random but the object is not, so stacking dampens out the noise and reinforces the object you want to see. But, on the moon, where there is sunlight there is a strong signal to begin with. That is, there is little dynamic range over the moon while, for deep sky, you're pulling hard to detect a very weak signal.

I've tried some HDR stacking to bring out the dark side of the Moon simultaneously with the illuminated side, but I haven't been happy with the results. But, research is continuing!

But at high focal length there is no doubt it helps. Increases contrast, decreases noise and just brings out detail. And, like I said, it doesn't hurt at lower mags.

[Catanonia]

Catanonia - I was just thinking about that question. I think the answer is no and let me see if this makes sense.

When you shoot deep sky, as you well know, you're trying to pull faint objects out of noise. The noise is random but the object is not, so stacking dampens out the noise and reinforces the object you want to see. But, on the moon, where there is sunlight there is a strong signal to begin with. That is, there is little dynamic range over the moon while, for deep sky, you're pulling hard to detect a very weak signal.

I've tried some HDR stacking to bring out the dark side of the Moon simultaneously with the illuminated side, but I haven't been happy with the results. But, research is continuing!

But at high focal length there is no doubt it helps. Increases contrast, decreases noise and just brings out detail. And, like I said, it doesn't hurt at lower mags.


Nice, thanks for the insight, there is me bringing my DSO experience (well 5 months worth) to lunar hoping it would work :)

Going to be at 3x Barlows tonight, 2700mm so will stack then and see what I get.

[Adrena1in]

Going to be at 3x Barlows tonight, 2700mm so will stack then and see what I get.

Be interesting to see that...I might have to get my 2800mm scope out tonight if it stays clear and see how the images compare. (Can't wait to get good conditions and chuck my 4x Barlow in to get some shots at 11,200mm!! Will definitely be using the webcam and Registax then! :D )

[jstep7262]

Looks absolutely amazing! Great job!

[Bernoulli]

I did a little test last night since we had such a big full moon almost at zenith. I took seven exposures (100 mm f/9 refractor, Barlowed to 2240 mm, into a 50D, ISO 100, 1/40 sec). They all got identical levels adjustments in Aperture and were exported to Photoshop. I stacked them with the "mean" mode, which averages the pixel values much as RegiStax does. No other adjustments

These are 500 x 500 crops at 100% of the Reiner Gamma region. On the left we have the stacked version and, on the right, one of the images that were stacked.

The stacked images had lower noise, but not better resolution. At this magnification, the images are about 0.78 km/pixel or about 0.4 arc seconds per pixel so I'm well oversampling my resolution (insufficient sampling is not the limiting factor in resolution).

Anyway, the stacked version is noticeably less noisy. I selected a small area of each in the upper right an boosted the contrast and brightness identically to bring out the noise, and you can tell there is much less in the stacked images.

Because of this, I've been stacking routinely for a while. At lower magnifications, it might not be doing much good (I'll check some prime focus shots at 900 mm later tonight). Stacking really doesn't take very long and seems to do nothing but good.

So I'm a confirmed stacker and I'd appreciate any comments or suggestions the group has.

[Catanonia]

Will be interested in the same test at prime 900mm mate.

[Adrena1in]

See, to my untrained eye, the stacked image simply looks like a softened version of the single image. (Though actually, looking again, about half way up, on the left, where those lighter bits are, you can clearly see there's a bit more detail, rather than just a softening of it.)

Note to self: Get webcam re-installed on PC and go for it the next time there's a good moon. I did have everything set up last night, did a bit of collimation, went indoors to watch James May then Around the World, then went outside again and saw it was cloudy and everything had been rained on!! Bu99er!!)

[Bernoulli]

I did a stack with the 900 mm prime focus shots and I could barely see any difference. Much less than the example above, which was at 2240 mm.

And, if I look at the full disk of the example shots on the screen, I can't see any difference at all. The disk in the example is 4450 pixels across, and the crops above are only 500 each. By the time you shrink the image by a factor of nine, the differences seem to dissappear.

So I stack just because it's easy. The real benefit comes if I use a 100% crop of the high FL images to show a specific feature but, even then, a photographer might notice the difference but not many folks from the viewing public will. But I notice so I do it!

This reminds me of the boxed set of remastered Beatle CD's I just bought (I'm a big fan). When I got home with them, I immediately put on Abbey Road and sat back in the easy chair to bask in what I expected to be improved sound. But it didn't sound much better at all to me and I was initially dissapointed that I might have spent $200 for nothing. But when I A/B'ed them (switched back and forth between the new and old tracks) the difference was huge! So I think it goes a bit to psychology, if you have the two to compare you can see the difference but, looking (or listening) to one or the other alone, you can't tell so much.

Well, I'm probably typing too much. I'd love to see results from other moon stackers.

[SteveInNZ]

See, to my untrained eye, the stacked image simply looks like a softened version of the single image. (Though actually, looking again, about half way up, on the left, where those lighter bits are, you can clearly see there's a bit more detail, rather than just a softening of it.)

That's interesting. The first thing that I notice is the noise reduction and to me, that on its' own makes it more pleasant to view. Where I think the stacking would make more difference is if you wanted to sharpen or increase contrast. The stacked image could be enhanced while the single image would only bring out the noise.

Steve.