Forum: Pentax DSLR Discussion
10-14-2009, 01:31 PM
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I know I'm a bit late to the game here, but it might be helpful for others.
If the local camera store doesn't have what you need, I would suggest a rubber bulb for ear flushing to blow the inside of the camera.
I wouldn't try wet cleaning of the sensor with anything but proper cleaning fluids and pads found at the camera store.
To clean the lens, I would try an optometrist (or whatever you call the store where you buy glasses) you can probably get some really good microfiber cloth well suited for the task. Don't use the cloth directly, but wash it thoroughly in mild soap and lots of clean water first.
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Forum: Pentax DSLR Discussion
10-14-2009, 01:16 PM
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Not necessarily something you want to do on your family shot for the x-mas card :o
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Forum: Pentax DSLR Discussion
10-12-2009, 12:54 AM
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That sounds like the most plausible answer. Considering the fact that there is no misalignment on the sides of the frame, it sounds even more so. Could be as simple as a small particle from production that has jammed in the mirror mechanism.
If this is the case, I wouldn't be so sure that you will see it, even compared to a working camera. the angle of the mirror doesn't need to be that far off to shift the image.
I would vote in for a trip to the store, or the camera repair shop.
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Forum: Pentax DSLR Discussion
10-12-2009, 12:42 AM
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It's a healthy habit that I fully agree upon.
If I see any dust in the viewfinder, I attack it with a hand blower. Not compressed air since that stuff, worst case, can destroy the mechanics inside the camera. I use a small rubber bulb that I squeeze to blow air. That will do away with most of the big particles. The rest I just ignore.
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Forum: Pentax DSLR Discussion
10-03-2009, 08:50 AM
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If you listen carefully, you will hear a short buzzing sound, a bit like a charging flash, for less than a second. If you can't hear it during power on, try the manual dust removal from the menu to figure out the sound. It's quite obvious once you know what it sounds like.
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Forum: Pentax DSLR Discussion
09-28-2009, 10:43 PM
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That goes for both the Pentax and the Metz 58 flash. It uses the pop up flash for communication.
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Forum: Pentax DSLR Discussion
09-28-2009, 10:41 PM
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Mine has just become wider with normal use. If I do the "Push in and shoot the card out" now, it will some times fall on the floor.
I have probably ejected the card 1-2 times each day since I got that camera at launch date.
It will definitely not affect the weather sealing.
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Forum: Pentax DSLR Discussion
09-28-2009, 02:31 PM
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Ah, the guy from the store in Oslo is lurking around here. Spooky :eek:
I'll ask for you next time I'm in the store. I'm busy with baby right now, so it might take some time though.
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Forum: Pentax DSLR Discussion
09-28-2009, 10:44 AM
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I have used that combo for a while now, and I didn't actually know that. I just tried it out, and it seems to be about right. When the flash is on, the frame rate is down the drain, maybe 1.5 to 2 pr sec. When it is off, but still in the hot shoe, it doesn't seem to affect the rate at all.
It's still a good flash for me though as I never shoot high frame rate series anyway.
I own all 4 of the mentioned lenses, and I love them all. I use to have a collection of L series Canon zooms for my 5D, but now I only have the K-7 and these 4 primes, and I don't miss the zooms at all.
The 35mm and the 21mm are sharing the number one place on my list of favorites. Then the 15mm and last the 70mm.
I have also read the mixed reviews of the 15mm, but I think it a really fine lens. It may be a bit soft on the edges wide open, and there are some vignetting, but overall I think the image quality is very fine. I think you will enjoy it very much once you forget what you paid for it:fedup:
One very good thing about the 15mm is how the flare and ghosting is controlled. It works very well with the sun both inside, and just outside the frame.
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Forum: Pentax SLR Lens Discussion
09-28-2009, 10:22 AM
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I used to own a Canon system, and with it a 17-40L lens. It was terribly asymmetrical when I got it, even on cropped sensor, not to mention on full frame, but it was a fairly straight forward procedure to align it. You should definitely try to get it fixed if it is still under warranty.
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Forum: Pentax DSLR Discussion
09-28-2009, 07:16 AM
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Since you're Danish (I assume), I suggest you visit the link I provided. I have written quite much about my experience there, but all in Norwegian.
The short story is that I am very satisfied, and I don't look back at all.
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Forum: Pentax DSLR Discussion
09-28-2009, 03:53 AM
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I made exactly that switch two months ago. Couldn't be more happy. Now I have a K-7 with 15mm, 21mm, 35mm abd 70mm Ltd. K-7 Speilbildet.no (In Norwegian)
I also have the Metz 58 flash, which I would recommend to anyone. Haven't tried the Pentax flash, so I can't compare.
Kjell
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Forum: Pentax DSLR Discussion
09-14-2009, 03:55 AM
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If I'm guessing right, the SR system is some sort of adaptive servo loop system, which makes sense since it need some time with the shutter half pressed before it starts to work properly. Servo loops like this is very hard to get robust, and there are lots of opportunities for oscillations and saturation. Or maybe the system fails to lock fast enough in certain conditions that the designers at Pentax did not predict.
Anyway, if this is a real problem, and Pentax acknowledge it, it should be fixable through firmware.
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Forum: Pentax DSLR Discussion
09-14-2009, 03:47 AM
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this one explains how to go about in pretty simple way The Online Photographer: On Testing a New (Digital) Camera, Steps A and B
You should do this yourself since the various raw converters are a bit different on how they data at or just below clipping. I managed to squeeze out 3.5EV steps before clipping on the K-7, but I usually only go 3 steps to leave just a little margin. I use LightRoom 2.4
Just to mention it, this has really nothing to do with dynamic range. The highlight margin is more or less fixed, and is related to how ISO is defined. If a camera from a different brand is different (my Canon 5D was only 3EV steps), it is only because that manufacturer has a different understanding of how the metering is translated to actual exposure. If you're interested in the dynamic range, you need to go into the shadows as well.
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Forum: Pentax DSLR Discussion
09-14-2009, 12:44 AM
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I have the latest firmware, but I must admit that I don't remember which firmware I had when I last saw the problem. I delete those images, and also I have started to keep SR off most of the time.
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Forum: Pentax DSLR Discussion
09-13-2009, 11:10 PM
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I too have seen worse results with SR than without some times. I'm a good handheld shooter that beast the 1/f rule.
Haven't tried to experiment with the casual approach. I will try and see what happens.
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Forum: Pentax SLR Lens Discussion
09-07-2009, 03:38 AM
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How I would love to throw away the hoods to save space and look more discrete. But I won't because:
1. They actually do improve IQ, both indoors and outdoors.
2. They protect the front element from bumping into stuff.
3. On a rainy day, the front element won't get wet.
I guess I could go without on some rare occasions, but then I stand the risk of losing them. Better to just leave them on.
Didn't answer the poll as the alternatives were slightly biased.
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Forum: Pentax SLR Lens Discussion
09-05-2009, 02:18 AM
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You may be right about the fact that the power supplied through the SDM power pins are not enough, but I'm pretty sure the polarity does not change to reverse the rotation of the focus motor. Do you know that as a fact? Any real references to back it up?
The ring type motor used in these kinds of lenses works in a very different way than the ordinary DC motors that most people know. They won't do anything if you just apply power. You need to have some controller electronics as well to make it happen. I can't find any references right now, but if you're interested in how it works, I google search including something like "How USM motor works" will probably give you some results. If I were to explain it myself, I need to make some drawings.
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Forum: Pentax SLR Lens Discussion
09-04-2009, 03:15 PM
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I don't know if it works or not, but power should at least be available. After all, the SDM lenses gets power some how.
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Forum: Pentax SLR Lens Discussion
09-04-2009, 12:15 AM
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If I understand it right, what you want people to try is not to take the lens apart, but only to rotate the focussing ring past the infinite or close range stops and see if that somehow tightens things up?
I have not seen how Pentax have solved the Quickshift stuff, but I know how Canon does it on their USM lenses, and I guess that is also how the rest is doing it. It's not that easy to explain in words, but I'll try.
The lens assembly that is focused is in the middle, and has some ball bearings attached to it. The USM motor ring is pressing at one side of the ball bearing, and the manual focus ring is pressing on the other. If the motor stands still, and the focus ring is rotated, the ball bearing will roll against the motor ring, and drag the lens assembly along. The same happens when you do the opposite. The lens assembly will rotate at half the speed as the focus ring, which can be seen on the distance scale. So, on these lenses there are no clutch systems or anything. When you rotate the manual focus beyond the stops, you will notice that the friction increases, which is caused by the fact that the ball bearings are slipping instead of rolling since the lens assembly refuses to move any further. This should not harm the lens as it is designed to take it.
The Quickshift on the screw drive lenses is a different deal though. On these lenses the focus ring moves when the autofocus is working. My guess is that there is some sort of autoclutch system that is activated when the screw drive starts to spin, and disengage when it stops. Maybe some friction coupling that expands when it starts to rotate. Or maybe a gear that is pushed in, like in the electrical starter engine of a car.
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Forum: Pentax SLR Lens Discussion
09-03-2009, 10:14 PM
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Hi, are you sure the AF system is not off a bit. How about trying to do some focus bracketing to see if you get a sharper image slightly offset from what the AF system settles on.
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Forum: Pentax DSLR Discussion
09-03-2009, 12:18 AM
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How about shooting dng instead. The dng compresses just the same as pef on the K-7, so there is no real drawback. I havent tried Aperture, but the preview works fine.
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Forum: Pentax DSLR Discussion
09-02-2009, 10:12 AM
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I just upgraded from 1.01.00.05 to 1.01.00.09, and it seems to have solved the problem.
In case anyone wants to dissect a couple of raw files, I made a before/after shot of a OOF wall after approx 3min video. The ISO was set to 3200. The temperature inside the camera was remarkably low, but the green line showed up even at 25C on the old firmware. On the new, there was no line at 28C.
You'll find the files here (at least for a couple of weeks): Index of /download |
Forum: Pentax DSLR Discussion
08-31-2009, 01:06 AM
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To comment on your question, which seems somewhat forgotten.
I looked at my K-7 right now, and I see no flexing anywhere when pressing the menu button. No metal clicking sounds either.
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Forum: Pentax DSLR Discussion
08-29-2009, 11:10 AM
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I may have been a bit unclear about what the problem was. On Canon (at least 5D and 20D) the instant review will disappear when you turn the thumb wheel, just like it does if you half press the shutter. This means you can operate the aperture at all times. On Pentax, if you operate the thumb wheel while the instant review is visible, it will just zoom in on it, and it will become sticky (no time out) until you half press the shutter. This means the aperture is not accessible during this time.
As for the histogram showing on the review screen on Canon 50D. I haven't tried that model, but if it works anything like 5D, you can press the "info" button while the review is visible to toggle the different views.
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