Photographer Catches the ISS Crossing the Sun and Moon | Hacker News Reader

Photographer Catches the ISS Crossing the Sun and Moon

petapixel.com

115 pointsColinWright25 comments

I think it's excellent that this item does get some love from HN, clearly some people share my interest in the combination of amazing technology (the ISS), amazing technology (the photos), amazing craft (taking the photos), and the interest in orbital mechanics, etc.

I am saddened to see that the submission has been flagged, as evidenced by the sudden plummeting in the ranking:

https://www.solipsys.co.uk/images/25594171.png

Screenshot from here:

http://hnrankings.info/25594171/

I know people's interests vary, and that's partly what makes HN interesting to me, but flagging this item seems at odds with the HN ethos of appreciating excellent work and amazing technology.

But there we go. It hit first place for a bit, so that affirms my belief that I do share interest and taste with at least some of the HN crowd.

Meanwhile, here's wishing everyone a Happy Perihelion.

It's sad, because I was writing up a big thread on how to get your own pictures or at least see the ISS for yourself, but the submission got buried as I was posting it. I'll probably just repost it wholesale next time a submission like this comes up again, since nobody is going to see it here :(

But I get it, the linked content itself and much of the rest of the discussion here is on the level of "hey look at this cool thing" without much of technical interest.

I get that they were taken at the same time, but really when you're blending two pictures to get this one, what's the difference between that and just photoshopping a picture of the ISS where it was at the exact moment.

Because you’re not inventing or changing any information, it’s a much different situation. Do you have any complaints about how the image sensor grabs pixels? Is having a red pixel and a green pixel next to each other much different than having a sensor for one kind of light next to another sensor for a different kind?

Both images capturing different aspects. How much the artist does composing the images effects the realism, but what was done seems to be quite real.

I guess you could ask this of nearly any astrophotography. Are the images the Hubble takes not really "photographs" because they're composited together from several black and white photographs?

Another question, if this had been done on film, would you feel differently? The process is the same (Well, more or less) to a double exposure. Does that not count?

I can only speak for myself, so to me this technique is kind of like how they did colour photographs in the 20th century [1] - taking multiple photographs from the same perspective with different filters.

For that reason, I would argue that these are 'true' photographs. Sure, things have been differently exposed, maybe some ultraviolet light has been brought into the visual spectrum; but for all intents and purposes, the light from the subject(s) hit the lens(es) at the same time and the composition is true to what actually happened.

Now, with all that being said, there are many famous photos that are actually composites [2] and what makes 'a true photograph' is still hotly debated.

Digital processing is such an integral part of modern photography that trying to decide what makes a 'true photograph' is bound to get messy.

[1] https://petapixel.com/2014/03/10/incredible-color-photograph... [2] https://www.youtube.com/watch?v=2NeyTEO_JP0

Here's a great history of the autochrome, along with some gorgeous examples of it: https://blog.scienceandmediamuseum.org.uk/autochromes-the-da...

>what makes 'a true photograph' is still hotly debated

And it depends at least somewhat on the context. For photojournalism, compositing, highly misleading crops, removal/addition of objects, etc. is pretty much verboten. Whereas art/nature/etc. photography is much more flexible.

I knew someone who used to be really into photography contests at his camera club and he ended up getting discouraged and stopping doing it with the switch to scanning and then full digital because so many other people had "better" but highly manipulated photos.

I never thought about Sun to be so fluffy. Moon is cold and rigid, it is well known fact. But I never wanted to lick Sun before.

The Sun looks remarkably like a sponge rubber ball. I just want to squeeze it and bounce it off something.

http://www.spongerubberballs.com/sponge-rubber-rollers/spong...

The ISS is actually a TIE fighter?!

Yeah given our tack record we're certainly the empire (cue in the Darth Vader music).

Are you from China or Russia?

France but I was speaking about humanity as a whole.

I’m pretty sure we’re Krikkiters.

That's what the Galactic Republic said just before it became the Galactic Empire.

No idea what this means. Can you elaborate?

The mythology goes, a democratic government called Galactic Republic turned into an autocratic Galactic Empire overnight. The subtext is that you're saying that we're not evil, those other guys are evil. I'm saying, that's what the evil guys would say.

Really going all out with the practical effects for The Mandalorian

While not knocking the technical skills of the astrophotographer, is the framing of the ISS not just a little bit deceptive?

The image of the ISS in front of the sun makes it look as if it is orbiting the sun, not 93 million odd miles away. Both the ISS and the sun are in focus, rather than say the ISS is in focus and the sun isn't.

Also the relative sizes would make it appear that the ISS is several hundred miles in size!

It's so cool that we can send things into space like this, I loved the sense of wonder and excitement getting my rockets in KSP to launch into orbit, but thinking about real life space stuff is about a thousand thousand times cooler! Even taking a photo like this and seeing a huge building flying around us at thousands of knots is amazing to me.

Another astrophotographer, Thierry Legault, has done many spectacular shots, including the space shuttle docking with the Hubble telescope when it was being repaired.

http://www.astrophoto.fr

This ought to be up there with the Earth rise photo as just emblematic of humanity's space program - they are jaw dropping.

Reminds me of the game Outer Wilds a lot. Super cool.

Great pictures, but even better editing! I've taken photos of both kinds of transit with pretty decent results, but I have no patience for editing - McCarthy's shots really pop in a way I don't know how to do.

It's actually not too hard to see the ISS or find a transit occurring in your area, there are great tools online to assist you.

https://spotthestation.nasa.gov/sightings lets you select your location and gives you sighting possibilities that can be up to a couple minutes long with the naked eye. These are fairly common and seem to occur in batches as the orbit of the ISS subtly changes day by day. The ISS orbital period is around 93 minutes, so sometimes you can catch multiple passes in a night - the issue is much more one of the evening being dark enough while the ISS is still receiving its own light from the sun.

To assist orientation I use the iOS app SkyView Lite, where you can search for the ISS and see its projected orbital path. The app was also useful for viewing the recent Saturn/Jupiter conjunction. I find with both spotthestation and SkyView, I have to look further above the horizon than either makes me expect.

https://transit-finder.com/ lets you find transits and near-transits in your area up to 30 days into the future. I've found their projections to be reliable and made about 10 attempts. After you calculate, you can click into "Show on Map" and then click the map to change your location to somewhere within the path, and you can choose exactly the chord that your transit will take. Andrew's "hours" searching for a perfect location is more likely just clicking around till you find a quiet street maybe on a hill - that's what I do. Clouds and fog day-of are a big factor in location selection, but actually knowing viable locations and being in the right ballpark is very easy.

As for equipment, I'm hauling around an expensive setup, but significantly cheaper options are doable and honestly should produce nearly as good of results. I use a Canon 5D III or 6D II - the important thing to note is these are full-frame cameras, so in "close-up" astrophotography they're a good bit worse than crop-factor cameras like the much cheaper APS-C 1.6x crop Canon Rebel series. https://www.dpreview.com/forums/thread/4154657 has a lot more discussion of pixel density/relative magnification/crop factors but what matters for you is honestly just having the most megapixels. For a lens I use the Canon 100-400mm IS with a 1.4x extender, giving me an effective 560mm zoom. For the cheap setup you could use a 70-300mm lens and save 90%+ on glass. A recent Rebel+70-300 lens kit can be found in the $400-500 range and would give you an effective 480mm zoom. I use a tripod and a wired trigger (such as, but not specifically this: https://shop.usa.canon.com/shop/en/catalog/remote-switch-rs-... ). This allows me to shoot without touching the camera, which will be extra important with a non-image stabilized lens.

The key is that a transit is a sub-second length event, and if you select one from transit-finder where the ISS in darkness is crossing a lit moon, you cannot see it coming. Most (or all, lmk if you know otherwise) automated trigger devices (hardware or software via apps) can't do sub-second intervals and the camera drive modes either are semi-automatic or shoot-until-full-buffer. Unless you can time your burst to the transit moment (which perhaps you can in a lit-ISS over non-full-Moon situation) you want to sustain your captures-per-second at a rate shorter than the transit duration (to guarantee you'll have at least one hit) and cover a much longer window than the event itself. Usually I will start shooting 60 seconds before the expected moment and overshoot by a minute or two, aiming for just over two shots per second. Test what your camera and memory card can actually sustain (card write speed can be a bottleneck here more than camera fps or buffer size) and use a card that has space for 500+ photos. Once you figure out your photo settings, you'll want to shoot at least one shot with the lens cap on so that later you may compare shots of the night sky with the sensor noise captured in the capped shot that might otherwise look like a false star or random blue pixel. Selecting the right camera settings is an art and a much longer discussion, but for now you just need to use Manual mode, manual focus (modern DSLR live view screen+magnified look is a godsend), aperture somewhere in f/8-16, and a shutter speed faster than 1/300.

This is a composite shot of the ISS passing the moon in March 2018 from lower right to upper left. I aligned several photos in photoshop by overlaying their moon positions, then made 10 vertical slices and selected the sharpest moon from the sequence and merged it all. There's very minor color saturation work (to separate the blue and orange a bit) and probably a minor sharpness tweak. EXIF data is included on this one if you want to compare settings. https://www.flickr.com/photos/ohwaitnvm/40282783635

This is my first hit ever, during the blood moon of January 2018. The EXIF is missing from the upload but the settings were ƒ/10 1/2000 400ISO. https://www.flickr.com/photos/ohwaitnvm/39289900094/in/album... The moon itself is about 850 pixels wide in the original image and the ISS is about 27 pixels, from which you can see a surprising amount of detail, though not quite as nice as the submission's pro work.

I have much less experience with solar transits (I've shot two, but editing is boooring and I haven't put them anywhere) but pointing your camera at the sun is not wise unless you have a solar filter such as https://www.bhphotovideo.com/c/product/1299066-REG/marumi_am... or I suppose the hydrogen-alpha solar telescope mentioned in the submission.

My takeaway is that maybe I need to pick up a 1.6x crop camera on the cheap soon.... And look into telescopes.

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