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03-27-2008, 12:16 AM   #1
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Exposure question...might be kinda dumb. (Long)

Had my K10 for a month or so now...at first only had an old M lens and was obviously shooting full manual, waiting eagerly for my AF lens. ( sigma 28-200 3.5-5.6 ) Pictures metered this way generally came out fairly decent as expected...but in real life situations I can't always stand there and take 6 reference photos to get the right exposure you know? Thats where the digital is supposed to come in..

I get my new sigma AF lens the day before my trip to Houston to visit my brother who uses an A700. So I've got my new camera and lens and we're sitting around taking test shots with my autofocus lens in Av and different modes and such...and it quickly becomes apparent my camera is underexposing up to 2 stops. I have read this is normal to preserve highlights and what not.. but in my opinion this is just awful. Add to this my brothers camera while being a better one for sure, was making mine look like a glorified single use kodak...

His photos in the same room with built in flash and sometimes using the same settings and exposure and such were coming out..well perfect. There was no over or underexposure...flesh tones and objects looked right on..exactly how I would expect ANY camera to take them honestly.. Now this could be because of a few things granted..most probably Sony's DRO feature which takes dark areas and brightens them up etc.. thats what I'm thinking. I tried literally every mode and setting multiple times and nothing would give me the kind of photo that popped off the LCD or monitor like I would expect. The pics were all very sharp so I am pleased with the new autofocus lens...its the camera I feel is lacking.


Now sure I could go and increase the EV comp and shoot manual mode with an auto lens (impossible alot of the time) and such, but that still didnt give the overall photograph I was expecting...all I got was dullness frankly..not what I was expecting after 3 months of research and deciding on the K10D...because of this I am considering the K20 because of the CMOS sensor and its sony-like DRO feature which I now feel is absolutely a must on any camera..


Also, is it normal when using the flash to get a brighter picture at a smaller aperture? I seem to get brighter photos at f7-8 than i do at f3.5 for instance with my 28-200..which goes against everything I have read on the subject to date.


Last edited by Oceanic; 03-27-2008 at 03:21 AM.
03-27-2008, 02:39 AM   #2
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Honestly, don't waste your time dabbling with an old M lens on a K10D because exposure will be inconsistant. This is a known issue with the K10D but not so with the K100D. I am sure the K10D will give better exposed pictures with the DA 18-55mm kit lens or any of the current lenses which have full electrical contacts between the camera and lens.
03-27-2008, 03:15 AM   #3
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The standard focus screen on the K10 causes problems with exposure when using the M or K series lenses. In my experience it was progressive overexposure as the lens was stopped down.

A simple solution is to swap the focus screen for a DS screen or one of the accessory screens made by Pentax. This cures the exposure problems.

Flash use with an M lens will be chaotic. The camera has no way of knowing what aperture you are using and so it is not a recomended combination if you want to use auto flash exposure.

I have a number of the old M and K lenses and love using them with the K10, but you need to get a new focus screen if you want to go this route.

Peter
03-27-2008, 03:18 AM   #4
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Hm, I think you guys have misunderstood. My results with the M lens have been fine..I can work out the exposure and get the picture I want. My problem is the camera is not doing this on its own with my autofocus lens as I was expecting.

03-27-2008, 03:29 AM   #5
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I have no experience with other cameras, but I find my K10D/Sigma 17-70/Sigma 500 flash underexposes. Its a PITA. I have alot of great, underexposed family shots from past occasions - all of which I have to adjust if I want them looking their best.

Pictures in sun always come out looking great though - unless I use fill-flash, at which point it gets a little hairy.

I'm not convinced that Pentax has got the Flash algorithms correct.

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03-27-2008, 08:28 AM   #6
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The K10d is a capable camera, but each person has their different requirements. Based on what you find lacking, I think you need to go through and tweak some of your settings to get what you want out of the camera.

Part of the problem may be the flash. Are you using the flash on the camera or an external flash. With a DSLR, you almost have to have an external flash to get something like what you expect. The built in flash just isn't that good. Of course you can adjust the ISO and other settings to get something without a flash assuming your lens is fast enough.

You've already had practice with manual mode on your manual lens, so try to see what is comparable and utilize it with the AF lens you got. You will probably have to find out what EV compensation value works to get what you'd like out of your photos. The EV is especially useful for Auto-Exposure modes. I've never used a camera that has that set well at the zero setting. On my K10d I have it set between +1/2 to +1 depending on the lighting.

Last, if you are looking for that pop, that is probably due to the processing. The K10d firmware is set to be more true to a scene rather than to make things pop (from my observations). However, you can go into the menus and change things like the contrast, sharpness, saturation to match what you would like to see out of the camera.

Just remember that if you are using RAW mode, a lot of these settings aren't actually saved to the file, but you have a lot more flexibility to change these things with your RAW software.
03-27-2008, 12:07 PM   #7
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The K10 simply does not put out a picture ready to go even though you can get closer with image mode set to bright for JPEG(pg 120) but rather needs to be adjusted in post production to bring out the best color and sharpness no matter how you shoot with it.
As to the old lenses I find that the quality of the old pentax glass is superior to most of the economic priced glass out there. The A series gets some beautiful sharp pictures.
If nothing else Pentax lenses used with the K10D allow for the use of the 16 point metering mode unlike the Sigma and other brand lenses giving much better over all exposure.
The K10 is a fine camera but does take some time to get the best results from it in my experience.
KennJ
03-27-2008, 12:32 PM   #8
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Ummm...lets approach this logically

Is the aperture ring at the "A" setting?

If so...

Do you have the same issues without flash?

If so...

Do you have similar issues with other "A" type lenses? (Borrow one or go to the local camera store to try one of theirs.)

This should rule out most of the obvious variables. The short story is that any recent model lens for Pentax should function properly out-of-the-box with the K10D at default settings...no tweaking needed. If it does not, there is either a problem with the camera or the lens.

03-27-2008, 01:15 PM   #9
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I was using the built in flash as was my brother. My photos were just simply coming out too dark, which no setting in the camera aside from ISO can fix according to all my playing with settings. Thing is, I don't want to and don't think I should have to sacrifice that much quality using ISO 400 or above just to get what another camera puts out at default settings and ISO100 with no noise. I know I'm talking about a camera that costs twice as much, so I guess I'll have to go at it that way. I just can't see how any camera can be *that* much different. I can go into ACRAW and bump up all the EV and everything, and sometimes that helps. But not only do I think I shouldn't have to do that, it doesn't really bring out the kind of detail and brightness I'm looking for no matter what settings I use.

As far as color and sharpness, they seem to be ok (AWB is sometimes off) and can always be fixed some in post, but I rarely need to. It's the entire exposure of the frame thats just not coming through and cannot be recovered to the extent that another camera records it by default with no PP.

The lens doesnt have an a-ring, its all camera controlled..its a real puzzle to me as to why I get brighter photos with less light coming in. Im guessing it might be a flash timing thing and the way the light reflects back into the lens?
03-27-2008, 01:57 PM   #10
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Considering that you are using the built in flash, I would bet that is all of your problem.

First thing... You can change your flash setting. The flash is adjustable for distance so that if you are taking photos of something far away you can have it fire brighter or if something is too close you can make it less powerful. There is a limit though at how far the flash works. Use your manual, but I think it is pretty easy to find through the flash settings (same section as the ISO settings).

Second... You really need to have an external flash to get great photos with a flash.

If you are like me (and can't afford an external flash), I make do and try to not use a flash as much as possible. You'd be surprised at how often a shot at 400 or 800 ISO can be hand held in indoor lighting (shake reduction is nice).

I think you'll find though that a lot of what you desire can be overcome by increasing the flash power.

Erik
03-27-2008, 02:12 PM   #11
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QuoteOriginally posted by Oceanic Quote
Had my K10 for a month or so now...at first only had an old M lens and was obviously shooting full manual, waiting eagerly for my AF lens. ( sigma 28-200 3.5-5.6 ) Pictures metered this way generally came out fairly decent as expected...but in real life situations I can't always stand there and take 6 reference photos to get the right exposure you know? Thats where the digital is supposed to come in..

I get my new sigma AF lens the day before my trip to Houston to visit my brother who uses an A700. So I've got my new camera and lens and we're sitting around taking test shots with my autofocus lens in Av and different modes and such...and it quickly becomes apparent my camera is underexposing up to 2 stops. I have read this is normal to preserve highlights and what not.. but in my opinion this is just awful. Add to this my brothers camera while being a better one for sure, was making mine look like a glorified single use kodak...

His photos in the same room with built in flash and sometimes using the same settings and exposure and such were coming out..well perfect. There was no over or underexposure...flesh tones and objects looked right on..exactly how I would expect ANY camera to take them honestly.. Now this could be because of a few things granted..most probably Sony's DRO feature which takes dark areas and brightens them up etc.. thats what I'm thinking. I tried literally every mode and setting multiple times and nothing would give me the kind of photo that popped off the LCD or monitor like I would expect. The pics were all very sharp so I am pleased with the new autofocus lens...its the camera I feel is lacking.


Now sure I could go and increase the EV comp and shoot manual mode with an auto lens (impossible alot of the time) and such, but that still didnt give the overall photograph I was expecting...all I got was dullness frankly..not what I was expecting after 3 months of research and deciding on the K10D...because of this I am considering the K20 because of the CMOS sensor and its sony-like DRO feature which I now feel is absolutely a must on any camera..


Also, is it normal when using the flash to get a brighter picture at a smaller aperture? I seem to get brighter photos at f7-8 than i do at f3.5 for instance with my 28-200..which goes against everything I have read on the subject to date.
Although late into this discussion, I must, after reading the other replies, state the obvious. The built in flash will not work with a manual aperture ring in any position other than A. It only works P-TTL. To enable P-TTL exposure, the lens aperture ring must be in the A position.

If the lens in question does not have an aperture ring, then it is a different kettle of fish, and as another poster has suggested, put another lens, preferably a Pentax lens, DA, FA-J or FA or F with the aperture ring in the A position.

I have been pleasantly surprised by the inboard flash on my K10D. With my 16-50, it works flawlessly (as long as I leave the hood off).
03-27-2008, 03:06 PM   #12
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QuoteOriginally posted by Oceanic Quote
I was using the built in flash as was my brother. My photos were just simply coming out too dark, which no setting in the camera aside from ISO can fix according to all my playing with settings. Thing is, I don't want to and don't think I should have to sacrifice that much quality using ISO 400 or above just to get what another camera puts out at default settings and ISO100 with no noise. I know I'm talking about a camera that costs twice as much, so I guess I'll have to go at it that way. I just can't see how any camera can be *that* much different. I can go into ACRAW and bump up all the EV and everything, and sometimes that helps. But not only do I think I shouldn't have to do that, it doesn't really bring out the kind of detail and brightness I'm looking for no matter what settings I use.

As far as color and sharpness, they seem to be ok (AWB is sometimes off) and can always be fixed some in post, but I rarely need to. It's the entire exposure of the frame thats just not coming through and cannot be recovered to the extent that another camera records it by default with no PP.

The lens doesnt have an a-ring, its all camera controlled..its a real puzzle to me as to why I get brighter photos with less light coming in. Im guessing it might be a flash timing thing and the way the light reflects back into the lens?
Just based on this post (correct flash exposure at higher iso) you seem to be exceeding the flash power/distance. Bumping the iso will just mostly adust the gain (much like correcting in PP) so your images are artifically boosted. To be certain do you have similar photos w/ f stop/shutter speed at 100 vs 400. Your "bright w/ less light coming in" statement seems to contradict this but worth a double chack I guess. Also be aware that specular reflections (hitting a mirror/glass ect) will (for most Pentax cameras) cause severe underexposure.
Another thing is Sigma reverse engineers the Pentax chip (cheaper than paying royalties) so some odd things can happen w/ them..........
Care to post some examples w/ f stop/shutter speeds ????????
As to "dull" well Pentax has the K10 set to natural and uses a processing tone curve(my assumption) that can make many photos flat appearing.
Not ruling out a bad camera though.
03-27-2008, 08:31 PM   #13
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Once again, my post really has nothing to do with using an M lens..not the issue here.

As far as the flash, I did try using it's own EV comp and didn't notice much of a difference. The shots were all pretty much taken in a typical room with a light/ceiling fan being the main light...and we were taking pictures of things around the room no more than 8 feet away..if thats pushing the limits I guess I need to take my illusions of digital cameras somewhere else like Sony haha.

I will get some test photos of the aperture anomoly soon.

The dullness cannot just be attributed to the way the camera processes the image..the sharpness and color and all are either already fine or can be tweaked in post. The dullness however is affecting the entire frame in the same manner of just simply being flat and severely underexposed leaving you nothing to work with, and in some cases hardly anything to even see...IE its not an issue of the difference between bright and normal modes of processing.
03-27-2008, 10:07 PM   #14
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Every one of my pentax digitals underexposes.

Its fine for me because I never want to blow the highlights. Yeah, if you want perfect jpegs to print from the DPOF function...it might be annoying

I shoot 99% manual mode. If I ever catch myself letting the camera thinkwhile shooting jpg, give it +.3 to .7 ev every time.

[you probably already know] digital cameras have less dynamic range than film. pentax favors highlight preservation over shadow detail. it is a compensation that many professionals that I know observe.
you can always bump up the exposure a bit, but you can never recover burnt out white highlights.....
03-27-2008, 11:30 PM   #15
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What kind of metering mode were you in? I get consistently poor results when in matrix-metering, but centre weighted or even spot, when combined with exposure lock so I can focus/meter then recompose, yields fairly accurate exposures. If you are shooting in matrix (the green metering option), consider switching to centre weighted or spot. If you're serious about getting accurate readings off your in-body light meter you're best served with one of the non-auto options.

Also, do you have the same problem when not using a flash?
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