So that is why it does a 30 sec exposure for movement evaluation of the stars, and that's why it works better on longer focales, where the "traces" becomes more obvious to calculate, compared to a wide-angle, where the star trails becomes harder to figure out (here's the 500 rule for astrophoto comes into play).

I guess that the big picture of that new feature if I understand well ?

Indeed.

[MossyRocks]

You won't be sorry getting the K-3 Mark III!

Well it arrived a day early so now I just need to sort this monster out. There is a lot more to it than my previously newest camera the K-3ii. The menus are a bit overwhelming and going from the K-3ii to the K-3iii is bigger difference than going from the K2000 to the K-3ii. Still haven't taken a picture with it

here's the 500 rule for astrophoto comes into play

That really only works for film where you have reprocity failure for long exposures. A 500/focal length duration shot will show trailing on modern digital camera, especially along the celestial equator, 300 or 200 works better for producing not noticeable star trails and with 200 one can get slightly out of round stars.

[slartibartfast01]

Well it arrived a day early so now I just need to sort this monster out. There is a lot more to it than my previously newest camera the K-3ii. The menus are a bit overwhelming and going from the K-3ii to the K-3iii is bigger difference than going from the K2000 to the K-3ii. Still haven't taken a picture with it







That really only works for film where you have reprocity failure for long exposures. A 500/focal length duration shot will show trailing on modern digital camera, especially along the celestial equator, 300 or 200 works better for producing not noticeable star trails and with 200 one can get slightly out of round stars.

The equivalent of the 500 rule for APSC would be the 333 rule

The 500 rule... Also depends on the resolution.

[co1000voi]

i passionately love Astrophotography.
will it work on my Pentax KP?

i passionately love Astrophotography.
will it work on my Pentax KP?

If you buy a O-GPS1

[MossyRocks]

The equivalent of the 500 rule for APSC would be the 333 rule

Not really. Focal length is focal length and on K-1 you would still want to be using 200/focal length because of the pixel density so using 500 would show very oval to clearly trailing stars. The more pixel dense the sensor the shorter the exposure. The reciprocity failure of film is what really allowed the rule of 500 with out it you would be stuck at a similar 200 to 300 for a value for exposure to not get noticeable trailing.

[loyalt]

So I am a total noobie at this so forgive me if this is a stupid question. Does this make the camera move on some sort of tripod or is it all done in camera somehow? Fabulous image!

Good question! I was wondering the same thing!

[Robin]

This is truly exciting! If you've ever stood in the dark doing the GPS orientation dance only to be told it hasn't worked, you'll comprehend the huge smile on my face.

---------- Post added 12-16-21 at 12:18 AM ----------

I wonder if the "Pentax is a dinosaur" crowd takes notice.

Difficult to notice anything with your head in the sand...

[i_trax]

Good question! I was wondering the same thing!

It is all done inside the camera.
The sensor is moved by electromagnetic force so it matches the movement of the sky / stars.

[MossyRocks]

Do you have to use B mode or is that better than TAV or M and setting your aperture, shutter speed and ISO?

Bulb mode is correct and as far as I know TAV will never work and M doesn't enable the astrotracer functionality. I know it doesn't on the old K-3 and K-3ii but newer cameras I am not sure. If you have the GPS attached on these older cameras you can switch between regular bulb mode and astrotracer by pressing the green button. I need to figure out how to use/enable it on my freshly acquired K-3iii but it will be cloudy for several nights so maybe next week.

Does this make the camera move on some sort of tripod or is it all done in camera somehow?

As others have stated it moves the sensor using the IBIS system. Basically it turns the sensor into an alt-az mount that also does field rotation. There are limitations like tracking time and ultra wide lenses will have problems as you move out from the center since the movements of the stars at the edges and corners of the frame will be substantally different than those in the center. However even with ultrawides doubling or tripling exposure time over 200/focal length, a good rule for trail-less start shooting, should produce good results. With more normal focal lengths like 28mm and up that becomes less of a concern as the field of view is smaller but on the long end tracking errors show rapidly which is why I have only ever managed consistent good 20s shots using astrotracer at 400mm.

[Rondec]

It would pretty neat if it actually froze movement of celestial bodies for the period of the exposure. It seems like it would be a simpler process than all of this mathematical mumbo jumbo.

(Maybe a bit akin to my idea that the easiest way to lose weight is to move to a planet with less gravity)...

[Weevil]

The equivalent of the 500 rule for APSC would be the 333 rule

Well that depends if one does the FL 1.5x conversion for A-PSC prior to the rule calculations ?

[MossyRocks]

Well that depends if one does the FL 1.5x conversion for A-PSC prior to the rule calculations ?

The FoV conversion isn't necessary. It is a function of actual focal length and pixel density. In the old film era the rule of 500 worked because of film's reciprocity failure so for long exposures the sensitivity went down hiding the trailing a fair amount but with digital there isn't the reciprocity failure so it will better show trails in longer exposures. Even with digital using 200 or 300 will show varying amounts of trailing but it is usually produces good enough results. if doing a stitched panorama one can go even longer as the trails will make up a smaller portion of the image and they will be even better hidden because of this.

[kwb]

It would pretty neat if it actually froze movement of celestial bodies for the period of the exposure. It seems like it would be a simpler process than all of this mathematical mumbo jumbo.

Careful, when Ricoh engineers freeze the Earth's rotation to give you the closest to what you're asking for, you'll be launched horizontally at enormous speed (e.g. ~830mph in Gladys, Virginia) relative to the Earth's surface that has been co-moving with you.
Pentax Dooms Us!