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10-21-2011, 04:20 PM   #16
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I believe the OP didn't post his files. But probably should do so for reference. :-)

10-06-2012, 03:52 AM   #17
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Just thought I'd post a reply here because there arn't many (any?) success stories with this hack.

I got it working, slightly different technique to OP. Instead of the [OPEN_DEBUG_MENU] command, I had to use the [DEBUG_MODE EN] command to enable debug mode. I'm going to try and detail exactly what I did.

I first tried OPs technique, however after testing an exposure of over 30 seconds, DFS still occurred. I then changed the command to [DEBUG_MODE EN] and loaded it up (holding down +/- whilst turning on). This time the screen was black and flashed on and off a couple of times, at first I thought I'd done something wrong but after a few seconds the camera returned to normal function. Now, after testing, DFS does not occur after an exposure of ~40 seconds.

So to recap the files I eventually used were

QuoteOriginally posted by MODSET.492:
QuoteOriginally posted by SYSPARAM.TXT:
There is a carriage return after [DEBUG_MODE EN] but not after [DISABLE_BULB_ALG] 1@.
10-06-2012, 04:34 AM   #18
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Just took a 915 second exposure (~15 minutes) with no DFS!! Well happy.

Here's the result, it's taken with the lens cap on. Now I see why DFS is so essential for very long exposures! There is probably some light leakage in this shot too.

09-04-2014, 12:54 AM   #19
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QuoteOriginally posted by ratchet Quote

Hopefully this information is of use. I know many people are wanting the ability to disable DFS for the KX. Not really a hack, but a nice thing to know. Please take caution if you are not familiar with the debug mode. This is not intended to be a tutorial, but a quick update for those looking for how to disable DFS for the KX, who like me, have discovered that DISABLENR does not work.

I was looking through the firmware 1.02 for the Pentax KX and noticed the keywords DISABLE_BULB_ALG. I gave it a try and it worked. I no longer have DFS using this command. I'm not sure how many things are contained in the algorithm that is being disabled, but definitely DFS is one item as the camera is immediately ready to take a picture with long exposures. I tested with a 1 min exposure and a 5 minute exposure. Definite increases in hot pixels and bloom with increased exposure time, but with image stacking and dithering these are easily eliminated in typical astrophotography (my hobby) image processing. I'm not sure if there are any other effects with this command yet. Still need to conduct more tests.

My camera and files are as follows:

Pentax KX (firmware 1.02, the following files in the root directory of the SD card, powering on while holding +/-, debug mode <EN>)

File Name: MODSET.492
File Contents: [OPEN_DEBUG_MENU]

File Contents: [DISABLE_BULB_ALG] 1@


Full Metal Ratchet
Here are some astroimages I took with the Pentax K-x where I disabled the mandatory DFS.


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