[Raybo]

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I used a Da 15 Limited, so I might get better results at say f16? And do I focus on infinity to get the stars to show as a clean line? I ask because I want to get buildings in focus with the startrails behind.

I'd use the 10-17 at 10mm and wide open, I would also drop the exposer time to < 1 hr (you want to let more light in not less). Nice image BTW!

Good luck,
Ray

[telfish]

You can turn on DFS in camera. It's called long exposure NR. For your photo, it will take another 1h45, so you would come back after 3h30 if the battery can sustain that long. I believe we are all curious to see the difference, if there is any.

BTW, with the amazing DR of the K-5, it should be possible to expose at ISO 80 and later apply some tone mapping to bring up the many dark stars w/o burning the bright ones

This one was at iso 80.

Tomorrow night if it's clear I will do one with the 10 mm fisheye wide open with DFS on for the same time 1 and three-quarter hours. I have the grip so if I fully charge both batteries I should be fine.

IS the DFS done automatically in camera and will it let me do that long an exposure with DFS turned on?

Just ran it through dynamic HDR quickly and this is the result.

[telfish]

Here is the HDR image, I might have overdone it a little
100% crop of raw added to show the noise levels.

[TiminyCricket]

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?

[kittykat46]

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

The original shot was very good, actually. You could do a bit of PP to bring out some more stars which appear "dark" - the K-5 sure has plenty of DR to do that.

...... 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?

The Pentax Infra-Red remote control is realy cool with Bulb Mode.
Press once to open the shutter. Press again to close the shutter later.

The K-5, with its amazing Dynamic Range and Low Noise (Zero Noise ?), is going to be a dream Bulb Mode machine.....

[Hypocorism]

The Pentax Infra-Red remote control is realy cool with Bulb Mode.
Press once to open the shutter. Press again to close the shutter later.

It is. And this, below, is significantly cooler;
DealExtreme: $3.27 InfraRed IR Shutter Remote for Pentax/Nikon/Canon/Sony/Minolta/Konica Digital Cameras (1*CR2025)
You can afford one for each day of the week and is so much less painful on the bank balance if you misplace it.

For anyone interested, expect around 2.8-3.1 metres max. reliable range by my measured test experience, the genuine Pentax ?might? likely do a bit more I'd say, but the el-cheapos cater admirably for my needs - and budget.

.R.

[krp]

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.

[Hypocorism]

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.

But how do you piss-off Canon/Nikon/etc users by firing off their cameras with that one?

Geez, you'd be no fun at parties.

.R.

[Rickster]

What's that thing in the bottom right? Power lines?
Otherwise it looks pretty cool to me

Looks like a rotating satellite to me.

I take that back ... didn't noticed the red trail at first glance. It's a plane.

[dtra]

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.

[Ash]

These are very good results - you will have to adjust WB though to get truer colours in the sky and trees - cooler and with +ve tint.

But that aside, you're getting the kind of results I've been after for a couple of generations of Pentax dSLRs. The clean images without DFS are just a marvel. Check your manual about DFS functionality and when it engages.

f/16 won't help since you'll be cutting down on the amount of light from the stars getting to the sensor (unless you really want to boost ISO - unnecessary when infinity focus at f/5.6 should be sharp enough).

Look forward to your next long exposure series.

[TOUGEFC]

I cant see anything wrong , in fact it looks impressive for no dfs!
As ash said just adjust your WB in pp.

[Alcazar]

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?

From the previous post, you might get the impression, that the difference is being made by the use of a IR remote, while it's actually a software function of the newer Pentax camera models.

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.

That being said, it may be that the mentioned IR remotes bring that functionality to the K10D, i don't know (mine doesn't; but it can also act as a cable remote, then it does, but drains its battery relatively quickly). You don't need to buy a IR remote to have that functionality on the K5 which is being used by the TO.

[Hypocorism]

That being said, it may be that the mentioned IR remotes bring that functionality to the K10D, i don't know (mine doesn't; but it can also act as a cable remote, then it does, but drains its battery relatively quickly). You don't need to buy a IR remote to have that functionality on the K5 which is being used by the TO.

Thanks for explaining that re Pentax models. It's good to know of some progress.

Fwiw; the K-x doesn't have wired input port like prosumer models nor permits in-cam control of manual shutter Bulb action, only a menu item for remote triggered action choice exists, viz;
Mode 1: push to start, push again to stop
Mode 2: push and hold to keep shutter open
So unless you have a convenient housebrick to leave resting on the shutter button, IR remote is a must for it in Bulb work.

.R.

[kittykat46]

From the previous post, you might get the impression, that the difference is being made by the use of a IR remote, while it's actually a software function of the newer Pentax camera models.

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.

That being said, it may be that the mentioned IR remotes bring that functionality to the K10D, i don't know (mine doesn't; but it can also act as a cable remote, then it does, but drains its battery relatively quickly). You don't need to buy a IR remote to have that functionality on the K5 which is being used by the TO.

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.