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09-02-2010, 04:56 PM   #31
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QuoteOriginally posted by Ryan Trevisol Quote
Thanks, I'll give those a try, though I really much prefer to just have it all in Raw. I have 83 out of 320GB free on my iMac so I need to either install a new hard drive or buy a redundant external drive, or get a new iMac.


I have an external backup drive. Plugs into the USB and away we go. No need to replace the computer if it does what you want it to (unless you're just looking for an excuse to upgrade ).

QuoteQuote:
In any case, I'll just shoot raw and learn to meter better.
This will help you more than anything else. RAW does give a lot of room to play with but if you're preference is for JPG out of camera, learning what the meter is telling you and how to apply it will improve things many fold.



09-02-2010, 07:15 PM   #32
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QuoteOriginally posted by piesforyou Quote
Shot #2 is reminiscent of many shots I've taken with the k-x. I wonder why it chooses to meter like this. I bet the histogram for that shot is almost entirely in the left side, whereas in reality you'd want the shiny metal on the right side.
The shiny metal *is* on the right - it's about a half a stop from clipping. The camera *could* have gone another half stop safely, but a full would have clipped.

Since the shiny part is a pretty sizable part of the image, the "average" is probably right about where ISO standards call for it to be - slightly left of center. So really, this exposure shouldn't be surprising at all.
09-02-2010, 07:18 PM - 1 Like   #33
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QuoteOriginally posted by richardm Quote
I'm getting the same results from my K-x. During post-process, I have to push up almost everything from 1/3 to 2/3 stop or more. I think in 2800 photos, I've had to pull the exposure down maybe 10 times and push it up every other time. I might get 5-10 correctly exposed shots per outing if I'm lucky.

My $120 CoolPix gave more reliable results as long as the light was good. I decided to start shooting +1/3 stop EV comp from now on. We'll see what kind of results I get after this weekend.
Sounds like either:

1) Your monitor isn't calibrated correctly, making pictures look too dark.
2) You happen to prefer pictures that are overexposed by ISO standards.
or
3) You shoot a lot of backlit scenes or ones with bright highlights for which you are *supposed* to have to dial in positive compensation. Many P&S cameras will deliberately overexpose these shots to give you the results you probably wanted rather than the results you asked for, but DSLR's tend not to.

Posting some samples would help.
09-03-2010, 05:29 AM   #34
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QuoteOriginally posted by Marc Sabatella Quote
The shiny metal *is* on the right - it's about a half a stop from clipping. The camera *could* have gone another half stop safely, but a full would have clipped.

Since the shiny part is a pretty sizable part of the image, the "average" is probably right about where ISO standards call for it to be - slightly left of center. So really, this exposure shouldn't be surprising at all.
Aye, you're right.

09-03-2010, 06:18 AM   #35
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QuoteOriginally posted by audiobomber Quote
I always find these "K-x underexposes" threads funny, because I get ticked at the K-x for blowing highlights at times; so AFAIC it has a tendency to overexpose in Matrix mode. My K20D and K100DS do NOT blow the highlights.
Dan, I'm with you on this one. I get matrix metered scenes in bright sunlight at nominal ISO 100 which are at the absolute max of what the sensor can hold, or maybe a bit beyond. If I am to use matrix metering at all, I prefer the safety margin at the bright end.

The shot below required a full stop or more of downward adjustment to get it to this level, and the light tiles on the middle far right are close to blown. Coincidentally, the stop of adjustment put the exposure close to the "Sunny 16" rule.

The bottom line is that you can set the K-x to expose for highlights or shadows, and it will follow your commands. It is just a matter of understanding exposure and knowing how the camera reacts. BTW, I know some love it, but I'm also not a huge fan of ISO 100 on the K-x. I can get most of the benefit of the K-x "protect highlights" mode by just keeping the ISO no lower than 200, as that mode requires.
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09-03-2010, 06:27 AM   #36
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QuoteOriginally posted by Marc Sabatella Quote
The shiny metal *is* on the right - it's about a half a stop from clipping. The camera *could* have gone another half stop safely, but a full would have clipped.
Agreed. The detail was preserved where it counted; the shot was more successful by making the metal darker and more detailed, but was surprising compared to how it actually looked to the eye.

Take these quotes together:
QuoteQuote:
right about where ISO standards call for it to be - slightly left of center. So really, this exposure shouldn't be surprising at all.
QuoteOriginally posted by Marc Sabatella Quote
2) You happen to prefer pictures that are overexposed by ISO standards.
Many P&S [and, it seems, Canikon DSLRs] cameras will deliberately overexpose these shots to give you the results you probably wanted rather than the results you asked for, but [respectable] DSLR's tend not to.
QuoteOriginally posted by JeffJS Quote
learning what the meter is telling you and how to apply it will improve things many fold.
I think these statements cut to the heart of the issue for beginners, and those switching from Canikon. I was both a beginner with my first Pentax, and now am switching back from Canon.

What people are complaining about in these threads isn't a fault of Pentax cameras. Pentax cameras adhere closely to ISO standards, just as Marc repeatedly brought out. The images are technically, correctly metered. If a correctly-metered exposure (i.e. the camera considers the majority of what is in the frame and prevents that majority from clipping) is not what you wanted, then the problem is a lack of understanding of how pictures SHOULD be exposed.

What you can't count on with Pentax Cameras in general is them bending ISO rules to make pleasing pictures without the photographer giving it much thought.

This is, in fact, one of the reasons I came back to Pentax. When I first got into photography, I had a superzoom P&S camera and it took some coaxing to get good photos out of it. Then I got my K100D and at first it seemed to underexpose, among other issues, but I learned. I took some of the best pictures of my life with that camera. The whole year I had the Canon, I took great pictures too, but I felt less connected to the process. It didn't really matter what I set it on, all I had to think about was white balance (cause it's AWB was atrocious).

I also play the guitar, and one thing guitar players will tell you is, the more effects you layer on top of your sound, and the more saturated (compressed, distorted) your guitar tone is, the more room you have to hide bad technique. Strip it all away and plug into a touch-sensitive amp with no effects. It'll expose all your flaws, and will react to more of the feel of your playing. It can be intimidating at first, but sticking with it will make you a better player.

I'm beginning to see that shooting with a Pentax is the same way. The camera's the tool, and the tool behaves predictably, and it's up to the skill of the artist to use the tool properly.

Let me just say what an informative and helpful community this is and I'm really glad I registered here.
09-03-2010, 06:35 AM   #37
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QuoteOriginally posted by GeneV Quote

The shot below required a full stop or more of downward adjustment to get it to this level, and the light tiles on the middle far right are close to blown. Coincidentally, the stop of adjustment put the exposure close to the "Sunny 16" rule..
Which just goes to show that, just because the cameras change, that doesn't change the fundamentals. There is no substitute for learning the basics, with any pursuit.

09-03-2010, 06:52 AM   #38
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This Cambridge tutorial has an excellent description of metering:

Understanding Camera Metering and Exposure

09-03-2010, 10:00 AM   #39
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QuoteOriginally posted by Ryan Trevisol Quote
Agreed. The detail was preserved where it counted; the shot was more successful by making the metal darker and more detailed, but was surprising compared to how it actually looked to the eye.
And this is going to be pretty common in high-contrast situations like this. The eye is amazingly good at opening and closing its iris as it darts from the light to the shadow area and the brain then conspires to produce the illusion that there is not such a great difference. So when we see an *accurate* rendition in a static photograph where our eyes and brain can't play those tricks, we're often surprised. Artists use tricks of their own to outsmart their eyes to avoiding being fooled by this - the most natural beginner mistake in the world is to underestimate the difference between light and shadow when working from life (as opposed to working from photographs).

BTW, I meant to mention before - looks like the maker notes have been stripped from the "shiny metal" photo, but I am curious about the setting of the "link AE and AF points" or whatever its called. If this is option is set, then the camera will bias the exposure toward the part of the image it has focused on in this case, the shiny metal. I'm guessing that option was off, though, because otherwise the shiny metal probably would have been rendered darker (closer to the middle of the histogram, rather than half a stop from the right).

I'll also add that I switched from matrix/pattern/multi-segment to center-weighted metering years ago. The former mode- the default - does try "a little" to guess what I might want, but does a pretty poor job of it. And it's guessing is such that I don't find it easy to predict what it's going to guess. With center-weighted metering, it makes no attempt to guess a thing - which makes it much easier for me to predict how it will behave. The end result is that I have to apply compensation at least as often, but it's way easier for me to predict even before I take the shot what kind of compensation I'll need. And the "center" is actually tight enough that I can use this a kind of a spot meter, allowing me to meter the light and shadow separately and remove pretty much any doubt. And better than a true spot meter, I'll get an "average" of a bunch of values in the light (and the same in the shadow), meaning I don't even have to find something "average" to point at.

QuoteQuote:
What you can't count on with Pentax Cameras in general is them bending ISO rules to make pleasing pictures without the photographer giving it much thought.
Now, to be fair, ISO doesn't actually care how a multisegment metering system sifts through the data to come up with an exposure in the case of scenes with high dynamic range - it really only cares about how a flat surface (eg, a gray card) would be metered. And some multi-segment meters will indeed deliberately overexpose the sky in order to render a backlit subject well, and ISO doesn't forbid this. But the issue is that people coming from an SLR background (as opposed to a P&S background) won't be expecting this, so they'll tend to naturally expect to need exposure compensation in these settings. So basically, you can either please the folks accustomed to P&S cameras, or the folks accustomed to SLR's, but it's tough to please both at once, because they really do have different sets of expectations. Obviously, Pentax could provide multiple modes - one to please people with SLR backgrounds, one to please people with P&S backgrounds. but you're never going to nail it completely. At some point it still becomes a matter of learning why the camera does what it does, and then anticipating this so you know how to meter effectively given how the camera actually works.

BTW, something else a lot of P&S cameras do is play tricks with the exposures curves when producing their JPEG files from the raw sensor data. A P&S camera probably wouldn't have metered the "shiny metal" picture any different (at most half a stop brighter), but it might well have decided to artificially boost the shadows to make them not so dark, creating the impression of a brighter picture. The K-x and some other newer DSLR's do have modes for this - "shadow compensation" or something like that. But for the most part, this is the kind of stuff one can do better oneself in PP, particularly if one shoots RAW, so you and not the camera is in control of how much brightening the shadows get, how dark the shadow has to be before it gets brightened, etc.
09-03-2010, 12:08 PM   #40
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QuoteOriginally posted by Marc Sabatella Quote
I'll also add that I switched from matrix/pattern/multi-segment to center-weighted metering years ago. The former mode- the default - does try "a little" to guess what I might want, but does a pretty poor job of it. And it's guessing is such that I don't find it easy to predict what it's going to guess. With center-weighted metering, it makes no attempt to guess a thing - which makes it much easier for me to predict how it will behave. The end result is that I have to apply compensation at least as often, but it's way easier for me to predict even before I take the shot what kind of compensation I'll need.
Very true. I tried out the Multi-Segment metering with the K-7 for awhile when I first got it and found it very unpredictable. Center weighted works nicely for me, and as you say, the necessary compensation is much easier to predict.
09-03-2010, 03:47 PM   #41
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QuoteOriginally posted by JeffJS Quote
Which just goes to show that, just because the cameras change, that doesn't change the fundamentals. There is no substitute for learning the basics, with any pursuit.

Yeah it is funny how those old rules are often a reality check.
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