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02-09-2010, 01:00 PM   #16
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I did follow up on the suggestions for verification. Here are the results.

I did if fact use manual popped up flash for both photos. The reason was to maintain control of the photos and to avoid the undesirability of long exposure time.
This was in the photos above. Those who saw this were correct.

I tried a custom 4 reset and setup 3 reset. After doing both, there was no change in performance at all. I thought I did that when I put in firmware 1.01. Apparently my memory was correct because there was no difference due to that.

I repeated the experiment without the flash as asked. The results were predictable as some of you senior members anticipated. Unfortunately, the LV display indicates about 6 seconds will be required!!! I did complete the experiment anyway. What i found was interesting. When turning off LV & taking the photo thru the view finder, it took 5 seconds, not 6. This was @ EV = +3. Reducing Ev to 0 now took 1/2 second instead of 5. Most of that is reasonable.
YES, there was a noticeable difference between the 2 photos this time. And
it was somewhat as predicted.
However, this is unusable by me for general purpose photos in the near future. I expect to be taking photos of people indoors. Asking them to remain motionless for 5 seconds is unreasonable.
This technique (1/2 second exposure) is probably good for photos of non moving objects & things. So it is good to know.

Conclusion: The flash does disable the EV comp control even though the LV indicated otherwise.
At least this is true @ distances of about 15ft, which was my focus point distance.

I am preparing for some photos next Wednesday. I want to control the results with reasonable predictability. The distances & controls that I am experimenting with here is what I want to have available for next week. I consider this experiment & all the comments to be very useful. They will help me to avoid surprises next week.

I did not say much about it because it was not a problem area, but, there is an
alternative to increasing the brightness under these circumstances. Simply it is,
adjust the High/Low control under the Image Tone section. I did in fact do that.
If more brightness is needed, it works just fine. Flash does not interfere with this.
So, that is the technique I will use for increasing brightness if/when flash is needed.

I can not say for sure that this technique is what I will use next week. I am experimenting now with things to avoid last minute surprises next week. I am very happy with the results so far.

I very much appreciate all your comments.

02-09-2010, 01:20 PM   #17
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In your sample pictures, they were taken with f13 and iso800. With these two settings, your build-in flash can only light up a subject maxmium about 8ft away. If you use f8 and iso1600 instead, it should increase it to maximum about 19feet away.
02-09-2010, 05:13 PM   #18
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QuoteOriginally posted by MichaelA Quote
However, this is unusable by me for general purpose photos in the near future. I expect to be taking photos of people indoors. Asking them to remain motionless for 5 seconds is unreasonable.
This technique (1/2 second exposure) is probably good for photos of non moving objects & things. So it is good to know.
You just learned the universal rule of ALL photography with ANY camera (not just an SLR): it's all about light. I'd point out that your K-x is actually better in this area than just about any other camera under $1500, my K-7 included.

QuoteOriginally posted by MichaelA Quote
Conclusion: The flash does disable the EV comp control even though the LV indicated otherwise.
At least this is true @ distances of about 15ft, which was my focus point distance.
It does not disable it, it simply locks the shutter speed. This is normal. When it comes to flash photography, a slower shutter speed wouldn't help anyways. The shutter speed is timed to get as much of the flash's output as possible depending on the focal length.

Built-in flashes don't do very well beyond 6 feet away anyways.

QuoteOriginally posted by MichaelA Quote
I did not say much about it because it was not a problem area, but, there is an
alternative to increasing the brightness under these circumstances. Simply it is,
adjust the High/Low control under the Image Tone section. I did in fact do that.
If more brightness is needed, it works just fine. Flash does not interfere with this.
So, that is the technique I will use for increasing brightness if/when flash is needed.
That's a terrible idea, you're essentialy introducing noise, artifacts and distortions in an effort to fake "brightness".

Did you really shoot these shots with an f16 aperture?!? No wonder the camera wants such a slow shutter speed!!! Try opening up the aperture a little, like f8 or so. You'll see a DRAMATIC difference. At f16, you're drastically reducing the amount of light that can pass through the lens. Your depth of field should be more than adequate for any indoor subject at f8.
02-10-2010, 01:20 PM   #19
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QuoteOriginally posted by MichaelA Quote
However, this is unusable by me for general purpose photos in the near future. I expect to be taking photos of people indoors. Asking them to remain motionless for 5 seconds is unreasonable.
Obviously. But also completely unnecessary. The meter indicated you needed 5 seconds because of the aperture and ISO you had selected. Pick a larger aperture and/or a higher ISO and shutter speeds get much faster. Basic photography 101. Typical indoor scenes are well exposed at, oh, somewhere around ISO 1600, f/2.8. and 1/30". If all you have are the kit zooms, you aren't going to get f/2.8, so you'll need higher ISO - or buy a "faster" lens (one that goes to f/2.8 or better).

02-13-2010, 11:44 AM   #20
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Other possibilities:
Regardless of EC, Pentax P-TTL is notorious for behaving unexpectedly if anything is highly reflective in the image. It will dial WAY back, even for pinpoint reflections! (Maybe the K-x improved this?)

As others have said, the flash could be maxed out.

If you had situations where the flash just plain did not fire, there are two possibilities:
1) Sometimes the flash slave doesn't see the master pulses in wireless P-TTL - if your slave has swivel/tilt functionality, angle it so the sensor on the slave is facing the camera and its master flash.
2) If you shoot too rapidly, the flash won't have time to recharge and will not fire.
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