[digitaldaydreams]

I'm new to astrophotography and need some help with creating a procedure list. Here's what I got so far.

K3II Astro Photography Setup Cheat Sheet.

Type of Astrophoto is:

A night Sky Photograph of Milky Way with some foreground features such Rocky crags.

No trails just static image with lots of crisp stars and galactic arm structure showing.

I want as little noise as is reasonably possible.

Assumes 14mm Rokiton/Samyang 2.8 lens (Aperture Ring must be set to A or it throws an error.)

1: Turn on Camera. (Since no astrophoto settings can be saved) All settings and calibration and lens focal length input, must be repeated every time the Camera powers up.

2: On Camera prompt to enter Focal Length. (The proper focal lenth of 14MM is not an available menu choice, so choose 15MM)

3: Hit Gps button and wait for satalite to have green bars.

4: Turn on Astro tracer found in Menu 2 via GPS

5: Do a precise calibration

6: Mount Camera to tripod.

5: Set ISO to around 1600

6: Make sure long exposure noise reduction is on.

7: Set file format to raw

8: Manual focus setting is grayed out in the menu so must be selected by physical camera lever.

9: Make sure long exposure noise reduction is on.

10: Twist lens focus ring as far as it will go towards infinity symbol.

11: Set exposure auto timer to 20 seconds.

12: Set self timer to 12 sec to avoid camera shake by shutter button depresion (I don't have a remote).

From what I've read it seems like this list must be close to a usable procedure.

Am I wrong about inability to save settings relevent to this type of astrophotography. ?

Did I leave out something?

Anybody care to help make this list better?

Thanks
For any help.
Frank

[photoptimist]

This is a very good start!

One issue is with setting the focus -- the extreme infinity end of the focus ring is often NOT in focus at infinity on some lenses. The best method is to use live view and check/refine the focus setting on a bright star or extremely distant point of light. If that's impossible, the second best solution is to focus the lens during the day on a very distant landscape object and carefully note or mark the exact rotation or tape-down the focus ring so it can't move.

[alpheios]

With the 14mm on your K3II you don't need to use Astrotracer when using a 20 second exposure. Stars won't blur due to movement with this combination of lens, camera and exposure time. Astrotracer enables you to expose much longer (up to several minutes) before the stars become trails. But since the sensor moves, everything in the foreground will blur.

If you really want to get most out of your pictures you have to do two exposures and blend them together in post. One with the aperture wide open using Astrotracer for the sky and one with the aperture stopped down for the foreground. This way you will get everything in the foreground nice and sharp and capture as much starlight as possible.

Also you should be using the 2s timer instead of the 12s timer. In 2s mode the camera locks up the mirror with the start of the timer whereas in 12s mode it lifts the mirror when it exposes at the end of the timer making it actually useless for your purpose.

[digitaldaydreams]

This is a very good start!

One issue is with setting the focus -- the extreme infinity end of the focus ring is often NOT in focus at infinity on some lenses. The best method is to use live view and check/refine the focus setting on a bright star or extremely distant point of light. If that's impossible, the second best solution is to focus the lens during the day on a very distant landscape object and carefully note or mark the exact rotation or tape-down the focus ring so it can't move.

Thanks, I'll need to discover exactly where this lens focuses at infinity and mark the lens body with a tiny white paint dot if needed.

---------- Post added 06-22-17 at 02:00 PM ----------

With the 14mm on your K3II you don't need to use Astrotracer when using a 20 second exposure. Stars won't blur due to movement with this combination of lens, camera and exposure time. Astrotracer enables you to expose much longer (up to several minutes) before the stars become trails. But since the sensor moves, everything in the foreground will blur.

Sounds like I'll only need the Astrotracer for lesser ISOs and Longer FL lenses.

If you really want to get most out of your pictures you have to do two exposures and blend them together in post. One with the aperture wide open using Astrotracer for the sky and one with the aperture stopped down for the foreground. This way you will get everything in the foreground nice and sharp and capture as much starlight as possible.

makes sense An F5.6 to F8 non tracked foreground shot perhaps.

Also you should be using the 2s timer instead of the 12s timer. As far as I know in 2s mode the camera locks up the mirror with the start of the timer whereas in 12s mode it lifts the mirror when it exposes at the end of the timer making it actually useless for your purpose.

Thanks I had no clue.

[jatrax]

Good start, thanks for working this up. Might end up as a good resource if folks keep adding tips.

---------- Post added 06-22-17 at 05:44 PM ----------

#10 twisting the focus ring all the way to infinity may not always be correct. Some lenses will go past infinity and even those that supposedly stop there might need adjustment.

[AstroDave]

#10 twisting the focus ring all the way to infinity may not always be correct. Some lenses will go past infinity and even those that supposedly stop there might need adjustment.

In my experience - hardly ever correct!! Of some 20 mostly Pentax and a few Canons, the only ones that even come close to focusing at infinity when turned all the way are some old M and A primes (28, 50, 135mm).

[mikeSF]

Good list, but I agree, definitely do not focus that way. Finding a distant street light or other pinpoint light on the horizon is a good way for starters.

[digitaldaydreams]

Regarding Focus. I went for the pre focus on a cloud during daylight route, noting the position.
Also even though it's manual focus lens the camera does beep when the focus is locked in.
I don't know if the focus can lock in ans beep on a star or planet at night yet. I'l try tonight

[jumbleview]

Did you turn off shake reduction?

[digitaldaydreams]

Did you turn off shake reduction?

Hi
I'm under the impression that when you use self timer that the camera assumes that it's on a tripod and shuts off shake reduction.
Therefore I did not include mentioning turning off SR.

[jatrax]

I'm under the impression that when you use self timer that the camera assumes that it's on a tripod and shuts off shake reduction. Therefore I did not include mentioning turning off SR.

You are correct about the timer turning of SR. But for completion it might be worth mentioning anyway.

[jumbleview]

Hi
I'm under the impression that when you use self timer that the camera assumes that it's on a tripod and shuts off shake reduction.
Therefore I did not include mentioning turning off SR.

In that case in item (2) it does not matter which focus distance to select, I think.

[abruzzi]

you don't mention what aperture you're using, I assume 2.8?

[scorman1]

Just got my astrotracer module for a K-5 ( posted my own thread recently), but have been doing unguided experimental astro shots for over a year.
BTW, the astro forum on DPReview is a great source for advise from some very serious photographers who are willing to share.
I take issue with a few of your settings/points of view:

A night Sky Photograph of Milky Way with some foreground features such Rocky crags.

No trails just static image with lots of crisp stars and galactic arm structure showing.

I want as little noise as is reasonably possible.

foreground features pose the problem of the astrotracer moving the sensor, so static items in foreground get blurred
with a WA lens you can get away with about 30 sec before the foreground appears blurred, otherwise take advise of previous poster
who explained taking one shots w/o tracer of sharp foreground

crisp stars immediately requires stopping down the lens, especially since WA lens designs are prone to distortions like coma (batwings), chromatic (color fringes) and astigmastism (diagonal lines)
luckily, the sensor tracking supposedly will let you get up to 5min, but realistically, more like 2min (only tracks x-y, but stars move in a great circle), so it is easy to stop down to f4 or f8 ( probably optimum sharpness w/o diffraction)

little noise requires ISO not to be any higher than 1600 but lower is better
The only way to get noise down is by taking multiple images of same subject and "stacking"...more is better, but foreground will move
For every 4x exposure, the noise goes down by 2x ...for scenery, 4 or 16 shots is probably decent

Key setting for any scene depends upon how clear the sky is ie the more atmospheric pollution (city lights, sun glow, moon glow, etc), the noisier it gets.
The histogram will tell you where to set f stop and ISO for a particular exposure time, by simply having the peak intensity located at the 1/3 of left side of screen
the raw out of camera image will look like crap w/o detail/color sharpness

Fortunately, on DPReview, a really sharp guy wrote a program named Sequator v1.3 which is free for downloading and allows single click stacking and correction.
Sequator
I gave an example in my thread ...35mm,120sec,f4,ISO1600, single vs stack of 4 images
Astrotracer O-GPS1 first experience - PentaxForums.com

2: On Camera prompt to enter Focal Length. (The proper focal lenth of 14MM is not an available menu choice, so choose 15MM)

yeah, this adds a geometric error which may reduce actual exposure time ...you'll have to experiment

5: Do a precise calibration

you omitted having to put the camera into bulb mode first, but here you need to do a coarse cal, first, then the precise mode ..two operations

6: Make sure long exposure noise reduction is on

This is WRONG ....turn it OFF

10: Twist lens focus ring as far as it will go towards infinity symbol.

Already discussed by other poster, buy I will amplify ....you set LV to 10x looking at the brightest star near center field of view (easier done w/ long FL).
On a zoom lens infinity will vary with FL, so focus at FL you are shooting ...temperature matters and may not be same in mid winter as summer temps
Some lenses will work at the infinity mark ...test it!

12: Set self timer to 12 sec to avoid camera shake by shutter button depression (I don't have a remote).

Get an RF remote ( which can be used as wired remote w/o batteries) ...I saw camera shake w/ 2min exposures when clicking by finger and also use mirror lockup.
One click lifts up mirror, second click within a minute releases shutter ....and heaviest tripod you can get your hands on.
https://www.amazon.com/Pixel-Digital-Wireless-Hassleblad-Replaces/dp/B01CJ5T...+remote+pentax


here are two links detailing (more than you might want to know
Nightscape Photography with Digital Cameras, Clarkvision.com
Astrophotography 101: A Lesson Series on Photographing the Milky Way – Lonely Speck

Now have some fun and go out and take some pics!
Stew