OK- this is simply phenomenal

Peeb · Feb 23, 2019

But I have no idea how he (Andrew McCarthy) did this.
https://petapixel.com/2019/02/19/this-guy-shot-50000-pics-to-make-an-81mp-photo-of-the-moon/

link:
Something about autostakkert (free) and lots and lots of shots- but why were 2 cameras necessary? Was it really necessary to take 50k shots?

Yes, the article tries to explain it, but seriously- how does this work?

Peeb · Feb 23, 2019

OK- it's become more clear now, the cheap cam that supplemented his Sony was used with a telescope. From the photographer on"Reddit":

My Equipment:

Sony a7ii (mirrorless camera)
ZWO ASI 224MC (CCD camera)
Orion XT10 (Dobsonian telescope)
Skywatcher EQ6-R Pro (tracking mount for telescope)

Link: I took nearly 50,000 images of the night sky to make an 81 Megapixel image of Tuesday's moon. Uncompressed image linked in the comments. [OC] : space

480sparky · Feb 23, 2019

Stacking multiple images for astrophotography is quite common. Remember, you're shooting through every mile of the earth's atmosphere. And through a telescope. That telescope not only magnifies the moon, but also the 'boiling' effect the air creates as it moves.

When viewed with the unaided eye, the moon looks perfectly tranquil. But even with a low-power 'scope (or decent binoculars), it appears more like you're looking at it through 20 feet of water in a pool filled with kids.

I've tried stacking 250 images of the moon, even when they're taken on a calm night. Can't say I was thrilled with the results.

Dikkie · Feb 24, 2019

50000 photos of the view we've all seen for years and still none from the back of the moon....

Designer · Feb 24, 2019

Peeb said:
But I have no idea how he (Andrew McCarthy) did this.
Something about autostakkert (free) and lots and lots of shots- but why were 2 cameras necessary? Was it really necessary to take 50k shots?

Yes, the article tries to explain it, but seriously- how does this work?

Given the fake-y "atmosphere" effect, and the re-oriented moon, I think a guy could do this shot in PS using only one photograph.

kalgra · Feb 24, 2019

A co-worker showed me this knowing photography was a hobby of mine. Sure its a nice image and I can appreciate it as such, but really 50,000 images, why?

I feel the same as @Designer, I could pull of a very similar image with no more than 2 or 3 images in PS. Perhaps this was intended for a very large extraordinarily detailed print in which case maybe it would be more impressive seeing such a print?

I barely read any of the article about this, did it take 50,000 images because he made this image with a late 90’s 1-2mp canon elf in the largest stiched pano ever???

kalgra · Feb 24, 2019

Ok I read the article, I found it very odd that no mention of the optics used was included, did I somehow miss it? Seems like an important detail. I still think 2000 images of each tile was overly excessive. The Sony A7II is not a shoty camera by any stretch of the imagination. I don’t see why the same effect couldnt have been produced with 50 or even 30 images per tile.

Edit- ok I’m a ding dong I see it all the other info now. :biggrin-new:

TCampbell · Feb 24, 2019

He was likely using the ASI224 as a guide camera.

In astrophotography, you tend to get a lot of noise build-up in images. You can reduce the noise by collecting more samples of data. The noise can be reduced based on the square root of the number of samples. e.g. with four shots of the same thing, you can cut the noise down to by a factor of 2 (or 1/2 of the noise). Take 16 shots and you can cut it down to 1/4. The problem with this is that you start to hit diminishing returns (hours and hours of more data starts to make only a very tiny improvement)

There's another issue ... which is that a lot of frames may need to be rejected due to vibrations, atmospheric distortions, etc. Stacking software such as AutoStakkert can help you analyze the frames and select say... the best 10% of them.

So basically you're collect a TON of data, knowing that most of it will be rejected ... and then of the data that isn't rejected you want enough of it so that the noise reduction.

The sunlit area of the moon is a fast exposure. So fast that you wont see any stars at all. Also the unlit area of the moon will be completely black. To get the stars to show up, you need a long exposure. To get the unlit side of the moon to show up (via "Eartshine") you need a longer exposure. But there are problems with tracking accuracy of the mount when doing this. SO... you use a 2nd camera as an "auto-guider".

When tracking a guide-star, the guide camera has a reference frame and then each successive frame is compared to that reference frame (it is typically taking an image every 2-5 seconds). If the guide-star moves by even a sub-pixel amount, the software will send a command to the mount to nudge it back on track.

The moon doesn't cross the sky at the same rate as the Stars since the Moon is in orbit around the Earth. But there is guide software that can guide on the moon.

adamhiram · Feb 24, 2019

I thought these results were pretty impressive, although 1000 stacked images per tile seems a bit much! I tried something similar last year, but with 50 stacked photos instead of 50k. Not quite the same results, but still a fun exercise.
The Moon - Superresolution

Braineack · Feb 24, 2019

kalgra said:
I barely read any of the article about this, did it take 50,000 images because he made this image with a late 90’s 1-2mp canon elf in the largest stiched pano ever???

he used high frame rate video -- his "images" are stills from video.

kalgra · Feb 24, 2019

Braineack said:
kalgra said:

I barely read any of the article about this, did it take 50,000 images because he made this image with a late 90’s 1-2mp canon elf in the largest stiched pano ever???

Click to expand...

he used high frame rate video -- his "images" are stills from video.

Ahh well I guess that is pretty cool. I would have never thought to do that.

Grandpa Ron · Feb 25, 2019

This is one of those photos where I ask why? The answer always comes back to Photo Art.

The objective in not a good photograph of the moon. The objective is to create a good picture of the moon. But, instead of brush, paints and canvas the artist uses a mouse, pixels and monitor.

Technology has opened up an entirely new field for artistic talent and folks are getting quite good at it.

So to address the OPs comment, yes it is a phenomenal picture of the moon, an excellent display technical expertise. However, as a photograph it is just another moon shot, though it does capture the earth shine rather well.

Braineack · Feb 25, 2019

the image viewed at 100% isn't even that great looking.

A specialized image stacking software is used. It first chooses best frames from the video to filter out those with possible camera shake or worst atmospheric distortions. Then the images are aligned to a sub-pixel level - much like the high resolution sensor shift modes work on Pentax and Sony, except the earth rotation is used instead of sensor shift. If you have enough frames to blend, you get higher resolution than the sensor and you get less noise because of averaging from multiple exposures.
In this particular case he used two cameras simultaneously for what is essentially HDR to control contrast between side of the moon lit by sun and the side that has earth's shadow over it.