[RobG]

Of course it does!
Otherwise even with a 16mm after 1 minute the stars would have a vertical trailing.
I have done many Milky Way time lapses with my previous body (KP) from the Pyrenees and the stars move not only horizontally.
Near the same location (Toulouse) I tried Astrotracer Type 3 and after 1 minute the stars are dead sharp.

OK, thanks! My understanding was that earlier versions of Astrotracer didn't cope with arcs.

Yes it does. I pointed it in the general area of polaris, near but not at it as there is a lot of crap blocking the view there from the park behind my house. It didn't have problems tracking with a 50mm there where there is a lot of rotation still.

Great, thanks!

[LaurentD]

This Astrotracer type 3 is a MIRACLE!
Yes you can frame a foreground (mountain etc.).

Here is an example.
April 4th, 2022, 5:36am in the Pyrenees, France. The Milky way above Bagneres de Luchon and the Spanish border.
1 shot for the sky, 1 shot for the mountains (otherwise blurred by the tracking)
Pentax K3-III APS-C DSLR
Zoom Sigma 18-35mm @28mm
ISO 2000, f/2.2, 50s

[MossyRocks]

OK, thanks! My understanding was that earlier versions of Astrotracer didn't cope with arcs.

Previous versions handled arcs just fine unless you are using an ultrawide lens with a very long exposure and don't have it centered on a celestial pole. I've shot a number of things close to polaris like M51, M81, and M82 with my 300mm and 400mm lens and my K-3 and never had problems with the large amount of rotational movement in the frame and that would have been with basically the original type 1 astrotracer. there may have been some issues with a beta version of type 3 astrotracer but with the final version it seems pretty solid.

This Astrotracer type 3 is a MIRACLE!
Yes you can frame a foreground (mountain etc.).

At 28mm you probably could have gone substantially longer for the sky portion. Last week I was out failing to get some aurora shots so eventually stuck a longer lens on and chased the Rosette Nebula for a while. I managed this with 19 shots that were 60s each with a 200mm (SMC A* 200/2.8 @F/3.5 and ISO 2500):

[RobG]

Previous versions handled arcs just fine unless you are using an ultrawide lens with a very long exposure and don't have it centered on a celestial pole. I've shot a number of things close to polaris like M51, M81, and M82 with my 300mm and 400mm lens and my K-3 and never had problems with the large amount of rotational movement in the frame and that would have been with basically the original type 1 astrotracer. there may have been some issues with a beta version of type 3 astrotracer but with the final version it seems pretty solid.

Thanks! Very interesting. I hope I can get clear skies one day.

[LaurentD]

At 28mm you probably could have gone substantially longer for the sky portion.

Yes, I will try.
But the day was coming so I needed to go fast.
As you know, time passes quickly when in the dark, in the snow, not easy to get a perfect focus (perfect at 18mm then I zoomed to 24mm it was bad! Even using tape to block the focus ring) etc.

Goodbye chicken dance for Astrotracer 1 calibration..

Last week I was out failing to get some aurora shots so eventually stuck a longer lens on and chased the Rosette Nebula for a while. I managed this with 19 shots that were 60s each with a 200mm (SMC A* 200/2.8 @F/3.5 and ISO 2500):

Wow! Incredible!
BTW why not using your 400mm?

[MossyRocks]

BTW why not using your 400mm?

I didn't bring that lens or the tripod to stick it on. The plan that night was to run multiple cameras on the auroras so I only had my "little" tripods and shorter lenses since I was going for some landscape shots with an old stone barn in the foreground with auroras dancing above but the auroras never appeared there that night. That is a really nice dark site and the night sky is dizzying when not use to that many stars so I would love to shoot the big glass there but it is a 3.5 hour drive.

But the day was coming so I needed to go fast.

I understand that and have been there many times. I probably could have gone with longer exposures at 200mm but I knew it would be great at 60s so I just went with it. Same with the ISO but I probably should have knocked it down to 2000 or likely 1600 or if I was doing longer exposures used 800.

[PentaxScott]

Random question -

Im currently under clouds virtually every night, so I havent tested it myself, but has anyone tested Astrotracer Type 3 while shooting the moon?

There is a lunar eclipse coming up in May, and having shot several in the past, there is very little light reflected off the surface of the moon during totality. While I dont expect much, even a 3-5 sec trace will allow me to get sharp shots at a proper exposure, so Im keen to give it a go.

[kypfer]

The moon is "moving" at a significantly different rate to the stars, which is what AstroTracer is calibrated for.
Engaging AstroTracer whilst making exposures of the moon is unlikely to have any noticeable effect on the image of the moon, though any stars in the background should appear less "streaked", if that's likely to happen at the sort of exposures used for the moon.
A wider aperture lens to enable you to keep exposures short is probably the only real practical solution.
Good luck

[jcr]

I use the O-GPS1 and after updating my K-3 III to firmware 1.41 I can no longer calibrate the compass. The GPS shows connected and locked in the camera, and GPS locations are correctly recorded in the image metadata. However, the Menu [Wrench] > 4 > GPS Options remains greyed out and disabled, so I cannot select to perform a compass calibration. The Advanced Calibration menu under Astrotracer is also disabled.

I tested the O-GPS1 unit on my K-3 (mark I) and could calibrate there, so it doesn't seem to be an issue with the unit itself. But the K-3 mark III could have different magnetic properties so the calibration may not be valid.

Calibration is necessary for the camera shot direction to be accurate, and needs to be done especially when traveling (particularly in northern Michigan, where iron ore deposits can affect the earth's magnetism by a significant amount).

It is possible that this issue started with 1.40 not sure. I have to imagine adding GPS-less Astro-Tracer touches the GPS code and perhaps introduced a bug.

Has anyone else seen this? I send a web support form contact to Ricoh and am awaiting reply.

EDIT to add: This bug appears to be fixed with firmware v1.50 per my own testing.

[Lloyd_Christmas]

Has anyone else seen this? I send a web support form contact to Ricoh and am awaiting reply.

I will see if I can calibrate tonight.

[RobG]

It is possible that this issue started with 1.40 not sure. I have to imagine adding GPS-less Astro-Tracer touches the GPS code and perhaps introduced a bug.
Has anyone else seen this? I send a web support form contact to Ricoh and am awaiting reply.

I haven't tried mode 1 or 2 since mode 3 became available. I did use it prior, and calibration worked OK.

[mctaveck]

This Astrotracer type 3 is a MIRACLE!
Yes you can frame a foreground (mountain etc.).

Here is an example.

Could you please crop one of the sky's corner? I find the corners always problematic since from 10mm up to 28mm stars are trails. Do you (all) have some examples where this is not present? I am talking from 60s seconds up.
Thnaks

[jcr]

I will see if I can calibrate tonight.

Bruce McNeil at Ricoh / Pentax tested and saw the same (GPS options disabled) behavior. But he also found a work-around:

1. Switch to Bulb mode [B on the dial]
2. Set [Camera] > 4 > ASTROTRACER >ASTROTRACER to "Type 1" or "Type 2" (i.e. the GPS-required options)
3. Make sure your O-GPS1 is turned on
4. Note that ��[Camera] > 4 > ASTROTRACER > Precise Calibration is now not greyed out and can be selected
5. Likewise ��[Wrench] > 4 > GPS Settings is no longer greyed out and so you can select > Calibration to calibrate the GPS.

He also forwarded the issue to the software team so hopefully we will see a fix in the next firmware release.

EDIT to add: This bug appears to be fixed with firmware v1.50 per my own testing.

[LaurentD]

Could you please crop one of the sky's corner? I find the corners always problematic since from 10mm up to 28mm stars are trails. Do you (all) have some examples where this is not present? I am talking from 60s seconds up.
Thnaks

I do not use focals shorter than 16mm (on the K3-III so 24 mm in 24X36 mm) otherwise big trailing in the corners.
On my K3-III the trailing with mode 3 is identical to mode 1 on my K3-III before installing V1.4 and on my previous KP.

I said it is a miracle because you do no longer need precise calibration and O-GPS1, you just press the shutter.

[Robert N]

I recently bought a Hoya 49mm Starscape Light Pollution Cut Filter as I live in the suburbs and thought this may help, with my DA smc 35mm f2.4 AL Lens, at f 2.8 on the K-3iii. Unfortunately light pollution was too great and the camera could not complete the calibration sequence. I tried again in an area with no light pollution. However with the filter on, and in post processing zooming in above 50%, artefacts were present around the stars (compared to an image without the filter). I decided to return the filter. I also tried to shoot with my 16-85mm f3.5-5.6 ED DC WR HD DA lens at 85mm, f 5.6, however there was insufficient light at the sensor to allow the astro function calibration. Hence a low f no. appears to be required, even for a longish exposure time. I must admit I am not a great fan of filters and normally don't use them as apart from a minor degradation in image quality, in certain circumstances I experienced a 'double glazed' type reflection in the image. The only time time I would use a protection or UV filter would be to protect the lens front element in harsh environmental conditions. Of course I always use a lens hood for protection.