Modifying a Pentax K110D for Astrophotgraphy

richard64 · 08-14-2007, 03:17 AM

As to remote shutter release - these are very easy to make. You need a 2.5mm stereo jack and cable (a cell phone hands free kit usually has a suitable cable), and some switches. If you short the tip to ground (the sleeve) then the shutter release is triggered. If you short the ring to ground then AF is performed. For night time you won't want to use AF, so all you need is a rocker switch between the tip and sleeve.

However, there is a problem with K100D (firmware 1.02) - I've posted this in another thread. Once the shutteer closes the camera pauses until it writes the photo to the memory card. This delay is the same time as how long the shutter is open! So if you open the shutter for 30s, after the shutter closes there is another pause of 30s until the photo is written to the card. Weird.

Richard

mph · 08-14-2007, 04:21 AM

Originally posted by richard64

However, there is a problem with K100D (firmware 1.02) - I've posted this in another thread. Once the shutteer closes the camera pauses until it writes the photo to the memory card. This delay is the same time as how long the shutter is open! So if you open the shutter for 30s, after the shutter closes there is another pause of 30s until the photo is written to the card. Weird.

Sounds like it's taking a noise-reduction frame. There may be a setting to control this behavior (I'm not familiar with the K100D to say for sure).

matiki · 08-14-2007, 08:41 AM

Originally posted by mph

Sounds like it's taking a noise-reduction frame. There may be a setting to control this behavior (I'm not familiar with the K100D to say for sure).

I was experiencing this very problem the other night. How aggravating.

I was looking through the menu a few minutes ago and I noticed you can turn the noise reduction off... perhaps this is the answer?

Edit- I should add, I can't test this right now as I've had to come into work and playing with my camera at my desk would be most detrimental to my newborn LBA (via loss of employment)...

richard64 · 08-14-2007, 11:46 AM

Thanks mph,

I went into the custom settings and turned off noise reduction and found that the delay disappeared. The photo was saved immediately. To be clear: after the shutter closed the photo was saved, with noise reduction on, after the shutter closes there is a delay equal to the time the shutter was open before the photo is saved.

OK, so this now raises another question. I guess what it is ddoing is seeing what noise occurs with the same photo taken with the shutter closed and then combining that with the photo. Does that sound right?

Richard

egarrard · 08-14-2007, 01:52 PM

Originally posted by pixelsaurus

Personally I would be very interested in your solution to timed exposures.

"One-thousand, two-thousand, three-thousand, etc...". That's how I do it. Lock the remote and count. It works great!

egarrard · 08-14-2007, 01:59 PM

Originally posted by richard64

OK, so this now raises another question. I guess what it is ddoing is seeing what noise occurs with the same photo taken with the shutter closed and then combining that with the photo. Does that sound right?

Richard

Yes. Well, more like subtraction. Here is a good explanation of doing it manually with PS.

**LeoTaylor** · 08-17-2007, 07:50 PM

jsteel77 - Great photo of a meteor! The red glow is not that bad. Focus looks OK to me. There is some elongation of the stars, I presume you used a photography tripod? I used a motorized astro tripod to track the sky. If you are operating the shutter by hand the 2 second mirror up delay works wonderfully.

I caught just two on Saturday out of 140+ RAW 1 minute images. The camera ran about 160 minutes unattended before the clouds got too thick just before midnight. As luck would have it the meteors came at the end when clouds were present. Added to the streetlights my results were pretty bad. I did catch 14 airplanes.

Next time I will travel to someplace a little darker.

Ricehigh - The IR filter is directly on the sensor, fortunately on the K110D only held on by four tiny screws. It is the only detachable filter I'm aware of, what is an AA filter? If I had not broken a switch on disassembly or if I recognized what I had done quicker I might have succeeded. I have no regrets, Pentax fixed it for $212 and now I have a great Nebula/IR camera. I can also use it for color astro with custom white balance.

**pixelsaurus** · 08-20-2007, 10:31 AM

For reducing noise and other gremlins,Iris is a freeware astro-editing program (details can be found in the help files and tutorials) and can be found at Iris software . I suspect it could be used for other purposes as well.

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08-14-2007, 03:17 AM	#16
richard64 Veteran Member Join Date: Aug 2007 Location: England Posts: 309	As to remote shutter release - these are very easy to make. You need a 2.5mm stereo jack and cable (a cell phone hands free kit usually has a suitable cable), and some switches. If you short the tip to ground (the sleeve) then the shutter release is triggered. If you short the ring to ground then AF is performed. For night time you won't want to use AF, so all you need is a rocker switch between the tip and sleeve. However, there is a problem with K100D (firmware 1.02) - I've posted this in another thread. Once the shutteer closes the camera pauses until it writes the photo to the memory card. This delay is the same time as how long the shutter is open! So if you open the shutter for 30s, after the shutter closes there is another pause of 30s until the photo is written to the card. Weird. Richard

08-14-2007, 04:21 AM	#17
mph Junior Member Join Date: Jul 2007 Location: Johnstown, PA, USA Posts: 44	Originally posted by richard64 However, there is a problem with K100D (firmware 1.02) - I've posted this in another thread. Once the shutteer closes the camera pauses until it writes the photo to the memory card. This delay is the same time as how long the shutter is open! So if you open the shutter for 30s, after the shutter closes there is another pause of 30s until the photo is written to the card. Weird. Sounds like it's taking a noise-reduction frame. There may be a setting to control this behavior (I'm not familiar with the K100D to say for sure).

08-14-2007, 08:41 AM	#18
matiki Veteran Member Join Date: Jul 2007 Location: Seattle Photos: Albums Posts: 393	Originally posted by mph Sounds like it's taking a noise-reduction frame. There may be a setting to control this behavior (I'm not familiar with the K100D to say for sure). I was experiencing this very problem the other night. How aggravating. I was looking through the menu a few minutes ago and I noticed you can turn the noise reduction off... perhaps this is the answer? Edit- I should add, I can't test this right now as I've had to come into work and playing with my camera at my desk would be most detrimental to my newborn LBA (via loss of employment)...

08-14-2007, 11:46 AM	#19
richard64 Veteran Member Join Date: Aug 2007 Location: England Posts: 309	Thanks mph, I went into the custom settings and turned off noise reduction and found that the delay disappeared. The photo was saved immediately. To be clear: after the shutter closed the photo was saved, with noise reduction on, after the shutter closes there is a delay equal to the time the shutter was open before the photo is saved. OK, so this now raises another question. I guess what it is ddoing is seeing what noise occurs with the same photo taken with the shutter closed and then combining that with the photo. Does that sound right? Richard

08-14-2007, 01:52 PM	#20
egarrard Inactive Account Join Date: Sep 2006 Location: Manchester, TN Photos: Gallery Posts: 51	Originally posted by pixelsaurus Personally I would be very interested in your solution to timed exposures. "One-thousand, two-thousand, three-thousand, etc...". That's how I do it. Lock the remote and count. It works great!

08-14-2007, 01:59 PM	#21
egarrard Inactive Account Join Date: Sep 2006 Location: Manchester, TN Photos: Gallery Posts: 51	Originally posted by richard64 OK, so this now raises another question. I guess what it is ddoing is seeing what noise occurs with the same photo taken with the shutter closed and then combining that with the photo. Does that sound right? Richard Yes. Well, more like subtraction. Here is a good explanation of doing it manually with PS.

08-17-2007, 07:50 PM	#22
LeoTaylor Site Supporter Join Date: Feb 2007 Location: Connecticut Photos: Gallery Posts: 679 Original Poster	jsteel77 - Great photo of a meteor! The red glow is not that bad. Focus looks OK to me. There is some elongation of the stars, I presume you used a photography tripod? I used a motorized astro tripod to track the sky. If you are operating the shutter by hand the 2 second mirror up delay works wonderfully. I caught just two on Saturday out of 140+ RAW 1 minute images. The camera ran about 160 minutes unattended before the clouds got too thick just before midnight. As luck would have it the meteors came at the end when clouds were present. Added to the streetlights my results were pretty bad. I did catch 14 airplanes. Next time I will travel to someplace a little darker. Ricehigh - The IR filter is directly on the sensor, fortunately on the K110D only held on by four tiny screws. It is the only detachable filter I'm aware of, what is an AA filter? If I had not broken a switch on disassembly or if I recognized what I had done quicker I might have succeeded. I have no regrets, Pentax fixed it for $212 and now I have a great Nebula/IR camera. I can also use it for color astro with custom white balance.

08-20-2007, 10:31 AM	#23
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	For reducing noise and other gremlins,Iris is a freeware astro-editing program (details can be found in the help files and tutorials) and can be found at Iris software . I suspect it could be used for other purposes as well.

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