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01-14-2008, 12:08 AM   #1
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What IS my K10d thinking??

I got my K10d a couple of weeks ago, and I have to say I love it.. but I just cant get the hang of exposure, flash and AF. .


I am experienced with photography, but NEW to dSLRs. In my K1000 days I would work off a simple formula ... based on the relations of shutter speed, ISO, and aperture. I would guide myself roughly with the camera's exposure meter and figure in flash power and distance when necessary. I would use this basic principle with minor variations, depending on what the situation was and what effect and composition I wanted to achieve. So, I could predict... that if I had a picture/subject that was properly exposed ( needle in the middle) at ISO 100, 1/100 and f4 that I could get the same results by taking the same shot at 100,1/60, and F5.6.. except now I have depth of field but the possibility of more motion blur.

OK, so I have just summed up the concept of basic photography... which is what I decided to test the moment I unpacked my new K10d, so so that I could have a reference to learn from..it being the middle of inter in the midwest, I have stuck to indoor photography.

I set the focus and metering modes to single point and shot only on M mode.

The first surprise was.. IS MY HOUSE REALLY THAT DARK... I mean shooting a test picture of a light coloured object, 4ft away infront of a white wall... with the f/stop at 4.0 , shutter speed at 1/45 .. I need to use ISO 400 and I was still getting underexposed pictures...


SO I adjusted the EV for the flash... to +1.0 and everything exposed fine. BUT HERE WHAT IS CONFUSING: everything exposed fine even if I set the shutter speed to 1/180, set the ISO to 100, and stopped down to F/8!!

I assumed the camera was just automatically adjusting settings (even tho it's in "M" mode?).. but the picture info is always as I set it, even if different settings are getting me the same results.

This may be my newbieness with dSLRs speaking.. but could I be overlooking?



Thanks all for your help...

01-14-2008, 12:24 AM   #2
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QuoteOriginally posted by dresden_phoenix Quote
The first surprise was.. IS MY HOUSE REALLY THAT DARK... I mean shooting a test picture of a light coloured object, 4ft away infront of a white wall... with the f/stop at 4.0 , shutter speed at 1/45 .. I need to use ISO 400 and I was still getting underexposed pictures...


SO I adjusted the EV for the flash... to +1.0 and everything exposed fine. BUT HERE WHAT IS CONFUSING: everything exposed fine even if I set the shutter speed to 1/180, set the ISO to 100, and stopped down to F/8!!

I assumed the camera was just automatically adjusting settings (even tho it's in "M" mode?).. but the picture info is always as I set it, even if different settings are getting me the same results.
Well, it is because you were using flash. Nowadays needed flash power is determined and adjusted by the camera automatically. So, you stepped down aperture, flash made more powerful discharge and you got correctly exposed picture.

Turn your flash off and you'll see that it's just the same as your K1000
01-14-2008, 12:27 AM   #3
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QuoteOriginally posted by dresden_phoenix Quote
(snip) I assumed the camera was just automatically adjusting settings (even tho it's in "M" mode?).. but the picture info is always as I set it, even if different settings are getting me the same results.

Your camera is functioning normally. In the P-TTL flash mode, the camera is adjusting the flash output to maintain proper exposure regardless of the aperture, shutter speed, or ISO settings you select.

stewart
01-14-2008, 12:30 AM   #4
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Hi Dresden Phoenix!

For starters, congrats with you K10D!
I guess there are less differences than similarities between SLR's and DSLR's. Although I am not an expert, I've been tinkering with flash more than I care for. What I think happened to you is the flash adjusting it's output to the metered exposure. At least, that's how I figured this. If you want more / less exposure, you can adjust the flash power from the flash menu..

Hope this helps and good luck!

[edit: Guess I was right! 3 posts in under 5 minute, we're nice people ]

01-14-2008, 02:24 AM   #5
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As others have said, the built in flash on shoots in P-TTL (which adjusts power to achieve proper exposure) when the lens is able to communicate aperture info.

I'm still trying to understanding how you're taking pictures. Where is the light meter at when you're shooting ambient (no flash)? What color is this object?

Also note you're using spot metering mode (meters only a very small area in the center of screen and ignores lighting from the rest of the frame), which measures light differently from what you're used to on the K1000 (which is using a frame average metering).

Multi-segment metering on the K10D is the closest you're going to get to your K1000 days, but they are still a bit different.
01-14-2008, 07:33 AM   #6
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I think you need to consider everything you are doing in total.

Are you using internal flash? It has a guide number of 11 meters at ISO 100

it is not that powerful but should handle your wall 4 feet away.

Note that maximum flash sync is 1/180.

I don't use internal flash, only external (AF540FGZ) and in manual mode with external flash you can set the shutter to anything below 1/180 to blend in the amount of ambient light you wish. This is really more of a question of the ratio of foreground and background you want, or the amount of shadow you wish to remove from a harsh directional light source.
01-14-2008, 09:07 AM   #7
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One other thing of note is that the K1000's little needle meter is full-scene average, not spot or even center weighted. The K10D doesn't actually provide this as an option -- you can get the matrix mode, which looks at the full scene but then applies voodoo which may or may not do what you want, or you can get spot or center-weighted. If you're used to assuming that the needle means the whole frame and compensating for bright/dark areas mentally, this can throw you off.

I know it seems kind of silly, but whenever I take my K1000 out for a little spin, I always miss the needle when I come back to my K10D. So simple and direct.
01-14-2008, 10:18 AM   #8
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Hey guys.. thanks for all your comments.

I was really just running the camera, and myself, through the paces.

I was actually 3-5 ft. away from my subject, a figurine of MAYOR MAYNOT from nightmare before xmas, a nice MID GRAY/ LIGHT GRAY subject and basic white wall background... indoor lighting from two 75w light bulbs on the ceiling (about 10ft above). Yes, flash would have needed even with non digital cameras.

But my K1000 , for example would say , you could get away with keeping the ISO at 100 and not using flash, while keeping the same aperture, if you set the shutter speed at, let say ... 1/20 or 1/30.... Or I could keep the shutter speed the same but increase the aperture two stops.

For the k10d I needed to set it to a 4" exposure .. Weirder still, once I set the flash to +0.5EV everything was correctly exposed (actually slightly over exposed) and I could even set my shutter speed back up to 1/60, 1/90, 1/125...even 1/180 and its not under exposed? How? Is the camera changing my ISO? My aperture? I am guessing it's changing the flash power... And why couldn't I correct a simple +.5EV correction in the flash by opening the aperture one stop OR slowing the shutter to the next slower setting?

I am trying to see everything as a whole.. as I was saying in my original post.. but it seems that the whole is different for my k10 than for my k1000, even if it would be the same picture.

It would be nice, for example ... to be able to compose a picture such as the one I described earlier, and after taking some sort of initial exposure reading.. Be able to PREDICT the necessary corrections for exposure, logically.

01-14-2008, 10:38 AM   #9
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You need to realize that P-TTL and Manual flash act very different.

It's called Flash Exposure Compensation (FEC), not flash power. The camera will use the flash according to its metering system. Once you set the +0.5EV FEC, it will always try to give you an exposure of +0.5EV as a result. So if you change the aperture, the camera will change power output accordingly because it needs more/less power to achieve your desired +0.5 Exposure Value.

With FEC, you are telling what exposure level you want in your photograph and the camera will calculate everything else to get you there. That's why changing the aperture appears to have no effect in your setup. If you wanted to compensate for that 0.5 stop of extra flash exposure, you're supposed to change the FEC, not aperture.

In flash photography, shutter speeds is used to control ambient lighting, not flash power (because flash duration is significantly shorter than even the fastest shutterspeed available). Since you are washing out all ambient in your setup with the flash, changing the shutterspeed will have 0 effect on the outcome of the photograph. So it does not matter if you're at 1/50th of 1/180 because the amount of time your camera is actually exposing for picture is roughly 1/20000 (typical duration of strobes).
01-14-2008, 09:50 PM   #10
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AVANT,

I think I am begining to uderstand, at least the FEC part.

Still I am concered that w/o flash I cant get a decent exposure even at 800 ISO and an f/stop of 4.5, shutter speed of 1/30. Even indoors ( two reg househol lightbulbs) iso 800 would have been EXCESSIVE to get just a simp[le expossure.


Which is what lead to my question is there an analog between digital and film. I am expecting the iso 200 setting to behave like 200 iso film, and the response to an f/4 apperture and 1/60 sec shutter speed in my k10d to be similar to having ISO 200 , f/4 with a 1/60 shutter speed in my k1000. Or is there something else i need to consider?
01-15-2008, 06:18 AM   #11
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I just think that your lighting setup isn't as bright as you think. I do a fair amount of low-light no-flash ambient only shooting, and I often have to go to f/2, ISO1000, 1/30s (or worse!), so I would be VERY happy getting ISO800, f/4.5, 1/30s.

EDIT - So are you saying you took out your K1000 and used it's light meter to get a completely different EV for the same lighting? Please clarify? Or are you just guesstimating what your K1000 would have given you based on your prior film experience?
01-15-2008, 07:39 AM   #12
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exposure 101

you need perhaps to look at the following link

Exposure value - Wikipedia, the free encyclopedia

it gives exposure values and shutter speeds for different lighting conditions.
01-15-2008, 09:11 AM   #13
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Egordon,
I didn't take a pic/develop with my k1000, but I did guide myself by it's internal exposure meter ( which is what I went by when shooting film anyway). The comparison is not entirely even, so I did guesstimate based on THIS: On my K1000 I have 50mm, f/2, prime lens on my k10d I have the 18-55 f3.5-5.6 kit lens. Using the same light and subject If I set the ISO to 400 on my K1000 I can "center" the exposure needle at around f/4 or f/2.8 at around 1/15 or 1/30 sec shutter speed( I assumed the difference came from me standing closer or further away from the subject and thus encompassing more "white wall") NOTE1: I would have never attempted the shot, hand held, w/o flash anyway as the slow shutter speed would have caused some blur. NOTE2: whenever I could "center" the needle on my K1000 my picture would be generally well exposed ( this is not to say perfectly, for development, or that I wouldn't spot meter for the case at hand.. just that I could count on a "snap-shot type" exposure, at least.)

So I guess that's why I was expecting similar results from the k10. I cant go gown to f/2 with the kit lens, obviously. But I figured at f/4 ( zoom set at around 35mm essentially 50mm once the crop factor if figured) that I would get an equivalent "centered needle" EV...for lack of any better term.
As I mentioned in my original post I figured I could still use ISO 100 or 200 once I included the inbuilt flash into the equation, but that's a separate issue.


It's not that I wasn't expecting SOME under exposure using no flash... Just NOT a BROWN pictutre or complete black picture at ISO 800 with a shutter speed of 1/8??? I was expecting something like losing shadow detail and maybe that "amber cast" one sometimes gets in under developed photos. Needing to slow the shutter down to 2" at ISO 400-800 just strikes as a bit extreme. But I am VERY new at digital.
01-15-2008, 09:31 AM   #14
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I think the OP has a K1000 with defective metering or is doing something strange with the K10D.

Although I don't have a K1000, I took a KX with my trusty 50mm F1.4, ISO set to 200 and metered off a wall wide open, between 1/30 and 1/60. I would guess at about 1/45 but the KX does not have this shutter speed.

I put the same lens on my K10D and metered again wide open with the K10D, ISO Set to 200 and it metered at 1/30 by pushing the green button.

As these are within 1/2 stop of each other, at least my cameras seem to agree. As a result it is not a generic problem with the functioning of the K10D
01-15-2008, 09:41 AM   #15
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hmmmm, let's see if we can nail down what's happening. So the light meter on your K1000 gives you f/4, 1/15s @ISO400 (ie the needle is centered), correct?
Pick up your K10D and put the mode dial in "M". Pick the same settings from above and see what the little exposure meter in the viewfinder says. I'd guess it would be pretty close to centered. Now if you take a picture of a white wall using those settings, I'd expect you'd get a nice picture of a gray wall. Let me know what you find...
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