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Comment by dheera | Hacker News Reader

Many of these nebulae that people see a lot on the internet are actually HUGE in the night sky, contrary to popular misconception that you need a Hubble telescope to capture many of them. A lot are much larger than a full moon, but just too dim for the naked eye to see. I've been doing a project to capture them in context with landscapes around California.

You can get quite a lot of detail with standard camera lenses; you just need a dark sky and a star tracker that lets you expose for long enough, and a different IR filter that cuts off at ~700nm instead of 640nm, so you can get the Hydrogen alpha line to pass through (which is actually within the visible band, but consumer cameras attenuate it to almost zero).

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Backing this up / supporting this, the image of the California Nebula is 2.5° long. That's five moon diameters.

I've got a Nikon 200-500mm lens, which while on the long side of lenses most people have, isn't especially hard to get... and its easy to get a 500mm f/8 mirror lens (which has the same field of view, along with no issues with bokeh for astrophotography). With a full frame camera, its field of view is 5°00'. The California Nebula would take half the frame. With a DX lens, that would be 3°10'.

The bigger challenge is the tracking.

Btw, given:

> I've been doing a project to capture them in context with landscapes around California.

Have you headed out to the Alabama hills? Yea... its star trail photograph rather than specific nebula - http://www.panoscapes.com/showImage.php?partNo=P250H&catNo=7... (its shot a 6x17 film camera - each frame is 6cm x 17cm - that's one shot; if you look at the full size prints you can see airplanes and satellites)

> I've got a Nikon 200-500mm lens, which while on the long side of lenses most people have, isn't especially hard to get...

True. All you need to do is go online with a credit card. The thing is, that's a $1400 lens new that still sells for over $1000 used in decent condition. That's a pretty decent chunk of change. ;)

You don't need to spend that much.

Get a used Nikkor ED Ai-S 180/2.8 or a Nikkor ED Ai-S 300/4.5 if you want to do the California nebula. Either should cost you under $200 if you're patient and good at eBay.

The bigger issue for the California nebula (specifically) might be that most of its light is at a narrow band of 656 nm which gets blocked off by stock consumer cameras; you might need to mod your camera's IR filter.

If you want an entry-level target, get either of the above lenses and image M31 (Andromeda galaxy) instead, which is visually of similar size to the California nebula anyway. Andromeda can be imaged easily with an unmodified camera. I always recommend Andromeda as a good entry level target for people after they've gotten bored of the Milky Way.

The most important thing will be to get a tracker, good sturdy tripod, and get to a dark place like a national park or national forest.

Of course. There's no reason you need the latest & greatest autofocus glass just to shoot stationary-ish celestial objects, that's for sure. And, that is one good thing about lenses, too: old lenses can keep on chugging literally for decades with little more attention than proper storage and some basic cleaning every once in a while.

I don't do astro, but I do shoot macro shots of stationary objects every once in a while. My workhorse lens is an older 105mm Nikkor (https://www.kenrockwell.com/nikon/105mm-f28.htm) that you can get in excellent to mint condition for little enough money that if it breaks or you drop it or something, you can just buy a new one.

It's truly a nice piece of glass, even though it doesn't autofocus with my body or auto-meter. It's every bit as sharp as Nikon's newest version of the same lens (https://www.bhphotovideo.com/c/product/424744-USA/Nikon_2160...), at 1/3 the price (or less), and without features I don't particularly need shooting stationary objects. You can even shoot a decent portrait with it, if you're not bothered by the lack of autofocus. Turns out there are lots of opportunities to save a little money if you don't care about having a fast lens to autofocus on a moving subject. :-) I spent more on my copy stand and stabilization equipment than I did on glass, and that was 100% the right thing to do.

If I had to share some takeaways from my experiences buying and using my DSLR + other equipment, I would say to focus on what you actually need, don't worry about getting the latest and greatest, and definitely consider used equipment. Following those principles, I got myself a couple of nice macro lenses, a D3400 body, a Kaiser copy stand, a lighting setup, and the cables & software to drive all of that, for around or maybe a little more than $1000. And, it works great & serves my needs just fine. Had I gone with brand new and current model stuff, I'd probably be well over double that.

Yes definitely. I own only manual focus lenses, and most are used old lenses and of terrific optical quality. I hate autofocus. I understand its use for wildlife, sports, and war zone journalism, but that's not what I do.

I shoot a lot of astro, landscapes, and some portraits, and I have time to compose and shoot for all of these, and I don't want some gadgetry between my hand and the glass doing its own thing.

There is good modern glass available, but it's not the stuff sold to consumers at consumer prices. In the consumer price range I've consistently seen better glass in used old lenses from the 70s to 90s. Before that it starts to fall off rapidly due to lack of anti-dispersive elements and good coatings, but there are still a few odd gems here and there from even before then.

Oh and as a bonus, with manual glass I'm not tied into one ecosystem. I own about 5 or 6 brands of lenses; I can freely change my camera body brand and just buy some new adapters.

The glass in my car is worth more than my car.

However, a 500mm f/8 mirror lens ($100) will do the job for astrophotography... and probably better for some aspects of it.

I'd also like to note that a lot of people spend more on the body of their camera than the glass (and accept using a 28-200 kit lens and complain image quality). It really should be the other way around - good glass is (nearly) forever. I got my 200-500 in 2015... and it was to double up / replace an 80-400 that I got in... 2013? Overall, my average spend of photography equipment is under $1000/year and that's an acceptable spot for a serious hobby.

I personally prefer long glass and have a particular style of photography I do with it (tightly cropped waterfalls are my favorite) and so I gravitate to the more expensive long lenses with a limited zoom range or prime lenses. ... but that's me.

> I'd also like to note that a lot of people spend more on the body of their camera than the glass (and accept using a 28-200 kit lens and complain image quality). It really should be the other way around - good glass is (nearly) forever.

I agree. I see people doing that and I just can't help wonder what they're thinking. A lot of people will get a bigger increase in image quality by using a $50 tripod instead of shooting freehand, rather than by buying the latest and greatest body.

... I've got 3 tripods.

They're even older than a good chunk of my glass. A pair of Manfrotto legs. One with a 3047 head, one with... I'd have to look it up, its another pan tilt head. Then there's also a carbon fiber with a rather light ball head (that's the one I take when I have to walk a distance). Everything is hex plate. I'd consider the arca-swiss heads, but when I was getting a good tripod I couldn't find a pan tilt head that I liked that was reasonable in the set of heads. The Arca-Swiss C1 didn't come out until later... and... well... yea.

While the $50 tripod is ok... the tripod often has issues like its only waist height without extending the (cracked) center column which increases its instability. They often don't have good QR systems and that leads to people not using it.

A reasonable tripod head is about $150. An acceptable aluminum tripod can be found for another $100... and those are worlds better than the $50 tripod. It wasn't something I learned until I broke my 3rd plastic tripod (or couldn't find more QR plates) in two years. I still have the 3001 & 3047 tripod that I got after that in... '00? or '01?

Again, this is a "invest in something good and it will last a lifetime" rather than "get the cheap equipment that will fail in a year or you will become dissatisfied with."

For small telescopes, you can spend more on the mount than on the glass when starting out. A good mount really pays off for long exposures!

> Have you headed out to the Alabama hills?

Yes! I have a couple of images coming, one of the Pacman nebula and one of the emissive regions of Cygnus, over the Alabama Hills. Stay tuned!

Is…that what the night sky would look like If we didn’t have so many electric lights???

Sort of, you can see the Milky Way easily if you just go to a rural area, and you'll see that even if there is no light pollution it's much dimmer to the eye than you see in photos.

Most of the other nebulae you can't really see at all with your naked eye no matter how dark it is, human eyes just aren't that sensitive. The Orion nebula is one exception, as it's extremely bright for nebula standards, you can see the core part of that nebula with your eye easily.

These photos are more like what the night sky would look like if it was dark AND our eyes were much more sensitive. Maybe some animals actually see it that way, I don't know too much about biology.

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