[gazonk]

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With the K10D, you have to keep your finger on the button to hold it down. The K20D and later models offer the function to press once for starting exposure, pressing again for stopping it.

Aha! You just gave me another reason to upgrade from K10D to K-5 - I can save my thumb from numbness when using my IR-remote!

(If anyone mentions wired remotes no, I will not pay attention )

[gazonk]

Here is the HDR image, I might have overdone it a little

The original looked fine to me, but you if you want it a little more "punchy", I'd adjust exposure slightly up, adjust color temperature a little in the warm direction if you want to get rid of the slightly blue background, and adjust contrast and black and white levels to make stars brighter and the sky darker.

[KxBlaze]

Are you talking about the tree being out of focus?

[TOUGEFC]

That is not correct.
Yes, One-Button Press for Shutter Open/Close is a firmware feature possible only with the K-7 and later bodies.

It is also fully tied to the Infra-Red remote.

Bulb Mode operated with the on-camera Shutter Button still functions as before i.e. the Shutter will only remain open as long as you keep pressing the Camera Shutter Button. Other than for experimentation, I never use it this way because it may shake the camera, no matter how carefulyl I press the shutter button.

Tip for you, when using the non-remote method, place a hat in front of the lens then press the stutter then quicky move hat away, then when you want to stop it just put you hat in front of it again

[Draecus]

Have heard about Deep Sky Stacker?
It's a nice program. You can Stick many Pictures together (Lightframes, Darkframes, Flatframes, Bias)
If I remember right you are also able to stack them to Startrails together.... it counts the noise with the Darkframes out of the pic.

[falconeye]

I prefer this one: DealExtreme: $4.80 InfraRed IR Shutter Remote for Pentax Digital Cameras (CR2025 Battery Included)
It simply has one button compared to that 10 button remote where only one button works. And it says Pentax on it.

This company certainly deserves honorable mention for their company logo!

[telfish]

The original looked fine to me, but you if you want it a little more "punchy", I'd adjust exposure slightly up, adjust color temperature a little in the warm direction if you want to get rid of the slightly blue background, and adjust contrast and black and white levels to make stars brighter and the sky darker.

Ok will try that on the one I will do tonight with DFS enabled.

[aragondina]

Looks friggin awesome compared to startrails done with my GX10 even with DFS and noise ninja! I think there is probably some base NR being applied even if DFS is turned off when doing long exposures.

This was shot in RAW? Which processor did you use to convert the RAW? I know ACR is very good at removing hot pixels whereas some thing like Capture One doesn't deal with hot pixels automatically. Can you post the original RAW for us to check out? I would like to do more startrails and if it is this clean the K5 might be an answer to having to stack the images.

[telfish]

Looks friggin awesome compared to startrails done with my GX10 even with DFS and noise ninja! I think there is probably some base NR being applied even if DFS is turned off when doing long exposures.

This was shot in RAW? Which processor did you use to convert the RAW? I know ACR is very good at removing hot pixels whereas some thing like Capture One doesn't deal with hot pixels automatically. Can you post the original RAW for us to check out? I would like to do more startrails and if it is this clean the K5 might be an answer to having to stack the images.

It was shot in RAW with ACR default settings noise wise, did tweak the levels a bit but not much.

Original RAW is here.


http://dl.dropbox.com/u/13738865/_K_71125.DNG

[aragondina]

It was shot in RAW with ACR default settings noise wise, did tweak the levels a bit but not much.

Original RAW is here in the photos folder.


https://www.dropbox.com/home/Photos?select=_K_71125.DNG#/Photos:::

Link not working

[vtqanh]

Did you mean 4500m or 400-500m?

If you want more range than the infrared remote has, you can try this type from ebay
Wireless Shutter Release Canon Rebel T2i T1i XS XSi XTi (eBay item 250721266136 end time 03-Dec-10 21:57:17 AEDST) : Cameras Photo
I have tested to about 20m anyway, but I did have an issue with it at altitude, stopped working up about 4 500m, which was annoying.

[vtqanh]

This company certainly deserves honorable mention for their company logo!

LOL - nice catch!

[aragondina]

Link not working

Ok, now it is.

[telfish]

I think the picture is quite impressive! One question though (and forgive me if it may seem stupid to some... I've never actually done anything with star trails before)... you mentioned using Bulb mode and an exposure time of 1hr 45 minutes. How did you manage to keep the shutter depressed for so long? Did you use a remote cable release and a piece of tape wrapped around it to keep the button depressed?

I used a cable release with a locking button. you press and slide to lock the shutter, though as others have said I could have used the IR Remote instead.

[Nass]

Hello,

I don't own a K-5 but do own a K-7 and do startrails. If the "wrong" you're referring to are aberrant pixels that show, ie in the 2nd picture (ie to the right of the top of the brightest trail), DFS is the tech you're looking for to remove those (called noise reduction NR in your cam I believe). This is something you need to enable before taking the pic which, as has been explained basically doubles your 'camera in use' time, once for the 100 minute pic and the same again (or maybe slightly less?) for the noise reduction algo to do its thing.

Those pixels are pixels in the sensor that throw a wobbly and get hot because of the long exposure time. When you switch on NR hat the cam is actually doing is taking another pic of the same time of nothing then taking it away from the first pic. As the pic is of nothing (a dark frame) it should theoretically just show up the dodgy pixels and the cam's internal brain takes one away from the other.

Where people like myself are mad at the K-7 is because we don't have a choice, ie you always have to have the camera in use for the double time (pic + NR) in bulb above 30 seconds. There is another way to do stratrails which is adding shorter exposures together. But the K-7's bulb limitation means you can't stitch together 60 second B exposures seamlessly because a 60 seconds actually means 60 seconds exposure then 60 seconds NR so there's a gap during the second 60 seconds.

Not sure if you can do this but try taking an additional bulb pic of nothing without NR with the lens cover on for a few minutes after you've done your 100 minute bulb exposure. That might give you a dark frame that you can use to subtract away from the original image manually (in photoshop or any one of several proggies that can do this for you).

Other things, the diagonal band across the middle looks like maybe some stray light, not wildly surprising for a 100 min exposure. Were you hooded? I've had that in the past on cold nights with condensation on the lens. I'm quite amazed you didn't murder that tree with that exposure time =).

The final image needs a bit more contrast to really show the trails, there are plenty in there though and that's just a bit of PP work. In my experience HDR isn't the best way to get a statrail because it makes the thing looks flat and noisy but hey YMMV . Also as has rightly been pointed out adjusting the WB might bring things out for you that you can't immediately see.