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05-22-2011, 07:24 AM   #31
Ash
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These are examples where my above explanation applies: trying to capture a high contrast scene and expecting the camera to meter for a brighter image result without appreciating the camera's priority to avoid blowing out the white highlight detail in the sunlit portion of the garage frame and fencing.

Your MM and CW metering examples show clearly the exposure bias towards saving the highlight detail at the cost of underexposing the rest of the shadow detail, which is to be expected. Your spot metered example is centred right on a shadow area of the fence, which the camera then assumes it should meter for, and has done so in the image - the shadow area is brighter, and as a result has blown out much of the highlights of the garage and rest of the fence.

Gaining an understanding of light and the importance of balancing it in your frame gives you a greater appreciation of how light can give you the best results.

05-22-2011, 10:36 AM   #32
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QuoteOriginally posted by davenn Quote
Hey Jeff

dang I have some serious reading to do there will work my way through all that.
including the exercise. I have in more recent times started to use RAW+JPG I should have done it a long time ago.

OK as promised I did some pics today, resized to 1024x680 and ~ 170kb each

http://www.sydneystormcity.com/IMGP1869a.jpg
http://www.sydneystormcity.com/IMGP1870a.jpg
http://www.sydneystormcity.com/IMGP1872a.jpg

69a .. multipoint
70a .. centre weighted
72a .. spot

All manual mode, I adjusted f-stop and or shutter for 0 (centre) exp. You wil see how I had to seriously lower the shutter speed in the spot metered pic tho it could have been a little faster
at 160th sec as with the other 2 the pic was metering ~ -2EV

hopefully you can read all the other EXIF data. Used that IrfanView prog, thanks Cats Five

Give me your opinions please
These are not the real serious underexposures that I have experienced

cheers
Dave
If you walk through the exercise a couple times, you'll definitely see the light, for what it is (pun intended ). Using it in the semi auto modes however means you have to know what you're after in the photo. For example... The Hound.



Exif | K5JS5752_mFA43_SiM_May10_2011 | Flickr - Photo Sharing!

(the photo has been fed through a Topaz filter for some effect)

He is black. With spot metering (in the semi-auto modes), and an EV compensation of -2 (or around there), as long as I'm aiming the camera at Him, I'll get a good exposure. Regardless of the lighting he's in. The actual lighting of the scene becomes secondary concern to me. Here my real concern is for higher shutter speed so I can capture him in action. With the K5, I have no problems letting the ISO fly free auto as well but in the above case, I think I had it fixed at 1600 to get faster shutter speeds (taken in Av). Once I know how the camera is going to see the light, I can concentrate on things like, is the camera AF fast enough to catch him (it is) and am I good enough to keep him in the frame (getting there).

Manual (M) mode is more ideal when you don't have changing light. That is, your scene or target is evenly lit such as on an overcast day or in an evenly lit room.

QuoteOriginally posted by Ash Quote
.......

Gaining an understanding of light and the importance of balancing it in your frame gives you a greater appreciation of how light can give you the best results.
What he said.... To expand, don't rely on things like histograms and pseudo tricks like ETTR (Expose to the right).. They are fine once you learn to look at your scene and understand what the camera is likely to do with it. Then you can judge if ETTR is the proper thing to do (which in many cases, it is not) and adjust accordingly.

Then again, there is always chimping.


05-22-2011, 12:07 PM   #33
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I suggest that you read the book Unserstanding Exposures by Brian Paterson . You will understand what is happening . The camera is OK
05-22-2011, 02:06 PM   #34
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I agree that you really should read up on exposure and metering. The pictures you posted are not underexposed in general at all - the fence is already *overexposed* in the first two, and *extremely* overexposed in the third. Now, it may be that you personally didn't *care* if you overexposed the fence, but the camera cannot read your mind about that. This is why you need to learn about how exposure works and how to meter effectively to get the results you want.

05-22-2011, 05:11 PM   #35
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Try clicking on the link I provided you in post #12. It will free you from the tyranny of your camera's meter.
05-22-2011, 05:44 PM   #36
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Thanks so much guys,

Appreciate you patience and teaching.

Bob will have a look for that book "Understanding Exposures by Brian Paterson"
Mprince , have bookmarked that page. Jeff, I will work through you exercise

I do a lot of storm chasing photography, as a result many of the pix are taken under rather adverse lighting conditions. And under such conditons, I rarely have time to do serious composure of the shot as things in the sky are changing so fast. I normally have left the ISO fixed unless really needing to adj it. Maybe I should also experiment with auto ISO as you commonly use Jeff.

cheers
Dave
05-23-2011, 12:21 AM   #37
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How about asking about camera settings on the storm-chasing forums I presume exist? It sounds a specialist field to me.
05-29-2011, 02:53 AM   #38
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QuoteOriginally posted by cats_five Quote
How about asking about camera settings on the storm-chasing forums I presume exist? It sounds a specialist field to me.
no this is a general issue of my operation of, or of the camera or both

ok was going through my archive tonite and found one typical example.....

The first pic I did was in auto (green) mode it was pretty much black. So went to manual and did several shots of which this was the best
Yes the sun is high behind the subject. So how do I get a decent pic in this situation?

Is this a time when I should use spot metering ?

What really frustrates me is my Fuji S9500 in auto or even my mobile phone camera will give an excellent pic in the same situation! So why cant my >$1000 Pentax camera

cheers
Dave

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Last edited by davenn; 05-29-2011 at 03:00 AM.
05-29-2011, 04:26 AM   #39
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Does it get it right if you pointed the camera away from the sun? We are getting examples of where it's 'wrong' but they all seem to be tricky situations - the strong backlight above, the bright wall in the other ones. Nothing to show if the camera *can* get it right in simple situations has appeared.
05-29-2011, 04:34 AM   #40
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That's a back-lit scene with lots of sky and a darker foreground resulting in a high dynamic range. No meter will do a good job with such a scene. That's why you, the photographer, must learn how to meter, which is why I provided the link in my earlier posts. In this particular scene, you should have exposed for the plane, sacrificing a blown out sky, then you could have taken a second shot, exposing for the sky. If there had been no people walking around, you could have then blended the image in post. With people around, you could still do that, but would need to use masking to replace the blown out sky with the properly exposed sky.

You also have dust on your sensor.
05-29-2011, 06:21 AM   #41
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That's one way of handling it.. The other way is to learn to use curves and masks and try to pick the best exposure between the light and dark. This is where learning to use the meter comes in handy. You used center weighted metering in a heavily back lit scene. It will get you every time.

... and yes, the sensor is dirty..

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05-29-2011, 07:15 AM   #42
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yeah I know it/was VERY dirty that was another prob with the K10D, constantly getting dust on the sensor, it drove me nutz, was constantly having to clean it. At least the K7 doesnt suffer that prob, its weather seal appears to be so much better.

speaking of which... is there a method in lightroom2.7 where I can take 2 images, let it see the commonly located dust spots and auto remove them from all subsequent images?

Dave
05-29-2011, 07:19 AM   #43
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QuoteOriginally posted by JeffJS Quote
SNIP... You used center weighted metering in a heavily back lit scene. It will get you every time.

So as I asked in the earlier post, thats a time when I should have used spot metering?

Dave
05-29-2011, 07:30 AM   #44
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QuoteOriginally posted by cats_five Quote
Does it get it right if you pointed the camera away from the sun? We are getting examples of where it's 'wrong' but they all seem to be tricky situations - the strong backlight above, the bright wall in the other ones. Nothing to show if the camera *can* get it right in simple situations has appeared.
I will do some pix in auto mode over the next couple of days, weather permitting. Its started pouring down outside tonite. hopefully rain will clear.

Dave
05-29-2011, 07:49 AM   #45
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QuoteOriginally posted by davenn Quote
So as I asked in the earlier post, thats a time when I should have used spot metering?

Dave
You would use spot metering if you know exactly what the meter is telling you. Truth is, that's a hard shot to get exposed properly in a single shot. If I were taking the shot, I would aim the meter (camera) at a mildly lit area of the airplane. You had your choice of complete shadow to full bake it sunlight. Pick a spot in the middle range. That will give you best opportunity for a Useable shot. You would still probably have to do some processing to scale back or bring out one area or another. As I've said earlier. Sometimes I'll just aim the camera at the ground (if concrete or similar shade), hit the green button (in M mode) and start there. Your AF shot may also be an example of where Matrix metering may have worked well.

It was my experience that the K10d tended to underexpose by a stop to begin with. CW metering supposedly gives preference to the center of the frame. Similar to spot metering but not quite because it also takes into account the rest of the frame and gives you an average. All of the old Matchstick needle type handheld meters can be considered to work the same way. Whereas Spot metering, only the center is used.

Now, back to your photo... One part of the airplane was nearly black, from what you are showing us. If, you had spot metered That part and used an EV compensation of -1.5 or so (Av or Tv), that would have insured the airplane at least, was well exposed and you might have had enough left in the sky to bring some of it back. This is kind of what I was trying to demonstrate with the picture of the dog. Regardless of what kind of lighting he is in, as long as I've compensated for the fact that he's black, using spot metering in one of the semi auto modes, I will always get a properly exposed shot of him. Side note, I use to scoff at EV Comp and I never touched the green button until I got my K7 and actually started using it. Sometimes, it's better to let the camera do the calculating.

Spot metering isn't for everybody. For some reason it scares people and they just don't want to take the short time to learn to use it. I learned to use it for black and white film. Where there is no chimping, no rear screen to see the shot instantly, no histograms, and it cost money to even process the film (even though I did it myself). My family reunions are always held in open air shelters that for all intents and purposes, are identical to the type of photo your airplane shot is. Beautifully exposed shots of the exterior showing nice detail in all the trees surrounding the shelter, beautiful color in the sky, and a bunch of shadows shaped like people running around in the shelter. Center weighted metering. The solution was to either use a flash (which people don't like) or learn to read the meter and the lighting.

I don't think LR has the ability to combine images. I could be wrong about that though. You need software capable of layers. It May be able to do an HDR type merge that will do the alignment and give you what you need. If you look through the link I provide about dirty sensors in my last post, you will see how I handle multiple photos that turn up dusty.

I hope some of that helps you.. I'll be happy to answer further questions you have.

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