[abruzzi]

How do you frame your image at night?

I ask becuase I've never done astro before, and as I was on a road trip last week to some beautiful country, I figured I'd give it a try. I setup at dusk and waited an hour or so for the light to die down, and tried a bunch of photos with my preframed shot. But I noticed that (I didn't realize) the direction I was shooting was also the diretion of the nearby town, so there was a lot more visible stars in any other direction. When I tried a different direction, it was impossible to get a good idea of the framing optically, I tried live mode, but it didn't seem to work much better. Are there any tricks to this, or is it one shot per night, that you frame up before the light goes?

[Mooncatt]

This is something that requires a fair bit of pre-planning if you are wanting something specific, like a constellation or the Milkyway core. There are charts online like https://www.lightpollutionmap.info that can let you know where the best low light locations are and also an idea of what directions to look to avoid "light domes" from cities.

Photo Pills is a good phone app to check things like moon phases and Milkyway core locations, including an AR mode to give you an idea of what to expect and where to set up. Want to capture the moon through a natural rock arch formation? Photo Pills can help you determine the precise location to set up, the date of whatever moon phase you want, and the time it'll be visible through the arch.

And then, of course, your subject matter. If you wanted a specific object in your shot, with a sky object in the background, but you had a light dome interfering, then you would use the above tips to plan again, but shooting from a different position so you can avoid the dome.

If that isn't a possibility, and you just really have to get a shot from a specific angle, then you'll need to do some extra work to prevent the light dome from interfering. That could include special filters, extra shots that you stack, shooting at a different time, or even shoot the sky separately and make a composite of it with the foreground.

[abruzzi]

yeah, I'm familiar with the software and the issues of city light, but my specific question is how to frame in darkness, can it be done, or does the viewfinder work for everyone else and my eyes are just bad? I tried jacking the ISO in live mode to a crazy number just in order to frame the shot, but it didn't do anything usable (not that I'd take the photo at 800000 ISO)

[Bob 256]

As Mooncatt described, it takes some planning. Based on lens focal length and center point, you should be able to locate some brighter star in the center of the field which you can use as a guide (that bright star will show up either in the VF or in Liveview on magnification). The planning involves picking the right focal length of a lens to include that portion of the sky you want to capture and you can approximate that using a star chart, knowing the field angle of the lens.

As you become more experienced (if you stay with astro-photography) is to use a guided mount with a "go-to" system. Once calibrated, a go-to mount will home in on a given object if you input positioning information for that object. This is especially valuable with narrow field objects because some of those will certainly be invisible to your eye and through a camera VF or with Liveview, and it will be the only way to point your lens at them (unless you use an auxiliary guide scope).

So to answer your question, yes the VF works for some objects that are bright enough (and you may need a fast lens to see these) but many stars just won't show brightly enough to allow framing, and never expect to see the stars looking through a camera as you do with your eyes.

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Last edited by Bob 256; 05-29-2022 at 11:43 AM.

[abruzzi]

yeah, at least with my initial tests, I couldn't see any stars clear enough to frame, but there weren't any particularly bright stars in that direction (southwest was my approximate heading.) My lens in the test was a Pentax-A 28mm ƒ2.8, so moderate, but not crazy fast. Moonrise was not for another 8 hours so I couldn't use moon light to help see terrestrial objects. I was wondering is a large, bright LED worklight could be used to usefully illuminate things on the ground while framing the shot. Here is one that came out ok (some star trails since I didn't use astrotracer). Thats the light of Moab in the distance. The illumination of the arches was from somone playing in the arch with a headlamp, which fortunately lit up the arch nicely:





(the camera was set to 800iso, ƒ8, and used B mode (configured in the setting to function like T mode) for about 130 seconds.)

[AstroDave]

I tried jacking the ISO in live mode to a crazy number just in order to frame the shot, but it didn't do anything usable (not that I'd take the photo at 800000 ISO)

Don't bother with live view - just shoot a frame or two at high enough ISO (1600-3200-6400) and long enough (probably 5-20 seconds will work) with your lens wide open (and zoomed if appropriate to what you want) to reach the sky limit. You don't really care if it is a "keeper" -- all you want to do is just look at it to see if it includes what you want, and is aimed where you want. That will also bring up whatever sky light pollution there is from light sources down near the horizon (cities or whatever). Re-aim and try this again until you are aimed where you want, with the framing you want.

[UncleVanya]

Liveview iso 25600 (or whatever your camera allows), frame, set iso back to your planned exposure etc.

[MaineNative]

I use the Samyang 14/2.8, so I use some street lights to determine the correct focus ring setting ahead of time. I always use manual focus for astro photography.

In the field, I check the focus and framing using test shots. I can’t really see much through the viewfinder, but I can see the test images. You can crank up the ISO to 6400 or higher for the test shots since these aren’t photos you intend to keep. Sometimes you can’t see the stars easy on the back camera preview, but as you adjust the focus, the diameter of the stars will get bigger or smaller. When the diameter is at its smallest, the stars are in focus. If the stars are too faint, you can place a night flashlight several hundred feet away and use the above method to determine focus. The test shots will also show the framing of your foreground objects.

I haven’t figured out a good way to use the newer quick-shift lenses that don’t have a distance scale.

[pixelsaurus]

I use one of these. It is a wireframe viewfinder off a Linhof camera. It fits the hot shoe on my K-70.

[interested_observer]

Here is an entire web article on the topic -https://www.lonelyspeck.com/how-to-find-the-milky-way/

Personally, I cheat! Download the photopills app on your smartphone for $10 and you are set. It's pretty easy to use. This way whenever you arrive at a location, afternoon, evening, or midnight - you can just hold up the smartphone to the sky and it will show you what is in that section of the sky in real-time. It has a planning mode where you can either give it the location or use your current location and it will tell you where and when the milky way will rise, its direction, and how it's going to move during the night.

What I did prior to getting photopills, is to use stellarium on my PC (free download). Using stellarium I would jot down on a sheet of paper the time that it rises above the horizon and the direction (bearing). Then with a compass when on-site - or better yet, using my K1, I would just rotate the camera to point in the direction, and would be all set up.

The best settings I have found using astrotracer is shooting wide open, ISO 800 @ 70 seconds (either crop or full-frame). Any longer than 70 seconds you start to get star trailing in the corners from distortion via the wide-angle lens. You can also shoot at up to about 40-second exposures with astrotracer enabled and get very little foreground smearing.

___________________________

Framing in the dark - setup your equipment, level everything out (for a milky way landscape), and then crank up the ISO to 51,200 and shoot 1 to 2 second frames. Take a look at what you have captured in terms of the landscape composition and make what ever adjustments you want, wash, rinse and repeat till you're satisfied. Focus on the stars, and you are good to go. Remember to turn down the ISO and to calibrate astrotracing.

[abruzzi]

I use one of these. It is a wireframe viewfinder off a Linhof camera. It fits the hot shoe on my K-70.

I like that idea. I have a Linhof rangefinder, but not the wireframe version. (I have a bunch of Linhof cameras) I also like the idea of test shots at high ISO until I like the framing.

As for focus, at the moment, I'm using old manual focus lenses where the focus ring stops at infinity, and so far, they have been spot on and its nice to just turn the focus ring until it stops.

[MossyRocks]

I usually scout out a location before hand either by going there during the day or by getting there well before dusk. Knowing where things are in the sky at different points of the night and year is something one develops with experience. One of the most useful things I use is the Stellarium phone app as it shows what the sky will look like at a given time and makes use of the compass feature so you can know where things will be when facing a direction. This is fairly common with the various planetarium apps but Stellarium has lots of things on the free side and a pretty complete deep space object catalogue with common and scientific names. The really nice feature is the grid it can overlay the sky with where the horizon is at 0 degrees and the zenith is 90. This allows you to have an idea of the framing if you know the framing of your lenses.

[Postumus]

Trial and error. I take images with assorted focal lengths to see what works best.
Then I turn the ISO to 10K and take a short 5-10 second image. Check, adjust and re-image.
Check and adjust until you get what you want. Then drop ISO, increase exposure and go for as many light frames
as conditions or your patience allows. Process, analyse and do it again...again....etc.
Some people get paralysed by too much thinking and too little dancing