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01-28-2007, 10:06 AM   #1
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confusion about auto iso on K100D

I went camping a couple of weeks ago and took a lot of photo's. I was not very happy with the photo's taken around the campfire. I took them with the regular flash and with a AF-360fgz. I notice that they weren't as bright as I thought they should be. I looked at the EXIF on those and notice that they all shot at iso 200. I shot these all in the auto mode but here is what I don't understand. When the camera is set to auto mode it brackets 200,400,800. I thought that it would use one of those iso as the camera needed. Why do they bracket those if it not going to change? I thought that it would move to what ever iso the camera would need in darker situations.

01-28-2007, 10:38 AM   #2
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quite how the k100 does its little auto tricks is interesting..

auto will always up the iso if it thinks shutter speeds or available apertures are not up to the job.. as a baseline rule the camera will always use the lowest iso it thinks possible.. the neat k100 feature is it allows the user to govern the iso range the camera uses while doing this auto trick..

the old way was to simply fix the iso..

but the k100 has a bug.. if any ev plus or minus is in use the neat auto iso trick fails and the camera defaults to iso 200 just as if it was fixed there..

this bug is probably your problem.. the other wierd thing is when the camera flash is in use and the plus or minus ev is used the camera alters its flash power as opposed to altering other things like apertures or anything else..

it works in ways that at first are not the ways one assumes it would use..

one thing interacts with another and not always for the best.. basically the camera isnt quite as clever as it makes out to be.. he he

trog
01-28-2007, 10:39 AM   #3
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QuoteOriginally posted by hmcfly Quote
I went camping a couple of weeks ago and took a lot of photo's. I was not very happy with the photo's taken around the campfire. I took them with the regular flash and with a AF-360fgz. I notice that they weren't as bright as I thought they should be. I looked at the EXIF on those and notice that they all shot at iso 200. I shot these all in the auto mode but here is what I don't understand. When the camera is set to auto mode it brackets 200,400,800. I thought that it would use one of those iso as the camera needed. Why do they bracket those if it not going to change? I thought that it would move to what ever iso the camera would need in darker situations.
Is the campfire itself in the middle of these images? It might have thrown off the metering.

I simply don't use Auto Pict at all. It's designed for ordinary, non-challenging photography - whatever the heck that might be. Pictures of puppies in the park taken in the early afternoon on partly cloudy days. Auto Pict is - as you have discovered - not so good at figuring out tricky photos. I have not taken any photos around a campfire in a while, but I think this can be a tricky situation in which to photograph.

If I am in too big a hurry to think at all about what I'm doing - or rather, if I'm flustered for some reason - I put the camera on P. But I still always hit the Fn button before starting to shoot in order to check (1) white balance and (2) ISO. And I look at the histogram at least for a couple of test shots to make sure the distribution suggests decent exposure. The histogram isn't able to tell you if your picture is in focus, but otherwise it's the most useful tool on the camera. And for what it's worth, you can view the histogram even after taking a picture in Auto Pict mode.

If you're not familiar with the histogram, I urge you not to be afraid of it. I know that I stayed away from it for a long time because it looked like a graph and brought up bad memories from my long-gone school days. But actually, you don't have to pay attention to the details in the histogram - certainly not to get a lot of benefit from it. A quick look at your histogram after your first campfire shot would have shown you that the exposure was too low - all the bars in the histogram would have been bunched way to the left of the graph. In Auto Pict you would not be able to do much about that. Perhaps you could point the camera at a darker part of the subject, lock the exposure, recompose and shoot. But a better thing would be to shoot in P and increase the ISO.

Will
01-28-2007, 11:35 AM   #4
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Guess I have a different point of view on auto -ISO. Why use it? I have another camera where half of the ISO ranges were so noisy that you never wanted the camera to pick them, so maybe I was just trained poorly.

I also think it's better to know what your camera is doing and its setting when you shoot. Giving it free rein makes you fall into bad habits or into a day of lost shots. Although in your case, trog, the auto iso bug got you some nice water photos.

01-28-2007, 12:01 PM   #5
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"Guess I have a different point of view on auto -ISO. Why use it? I have another camera where half of the ISO ranges were so noisy that you never wanted the camera to pick them, so maybe I was just trained poorly."

absoluley but the neat k100 bracket feature allows u to contain the camera to usable iso limits.. in my case its 200 to 800.. it also warns u when it is gonna use 800..

which makes it a damn shame that the bug when any plus or minus ev is dialed in wrecks it.. he he

the bug has been corrected in the k10..

the ability to pick your iso range and stop the camera ever going higher in auto than u want to is a brilliant feature.. just a shame we had to wait for the k10 to appear before we got one that works as it should do in this respect..

trog
01-28-2007, 03:50 PM   #6
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which makes it a damn shame that the bug when any plus or minus ev is dialed in wrecks it


I have never changed the ev +,- so that shouldn't have been a factor. 1 of the photos was at a f3.5 the other at f4.5. It that why it didin't change the iso up because it found a solution? I think I will try the P mode and change the iso manually. What about the mode shooting under candlelights, isn't that suppose to help us brain dead people?
01-28-2007, 04:52 PM   #7
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my old brain is pretty dead but i use p mode mostly.. p mode is basic auto but dosnt override any setting u dial in..

it might sound silly but its easier than trying to work out the other silly stuff which to me is mainly used as selling points to newbie buyers..

my method is simply.. i take a quick exploratory shot.. i take a quick peek at the lcd and work from there.. mostly the camera does a grand job all on its own.. u learn from experience when its not likely to and work accordingly..

i do set the little flashy highlight thing thow.. i find it helps

u thinks its under exposing u dial in some plus ev.. u think the oposite u dial in some minus ev.. u want sports u use av and set the shutter high the camera does the rest..

they could bin all the other autopic and scene stuff from my point of view..

but it sells cameras..

trog
01-28-2007, 04:59 PM   #8
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QuoteOriginally posted by trog100 Quote
... i use p mode mostly.. p mode is basic auto but dosnt override any setting u dial in..

it might sound silly but its easier than trying to work out the other silly stuff which to me is mainly used as selling points to newbie buyers.
By "silly stuff," Trog means (I hope) the scene modes. I agree. I think they are absent from the K10D and the the K100D would be better off without 'em. But Tv and Av and M are not any sillier than P. Just want that to be clarified for the record. :-)

Will

01-28-2007, 05:46 PM   #9
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"But Tv and Av and M are not any sillier than P"

yep thow i view tv and av as an extention to p.. they are still automatics just with a bias towards shutter or aperture.. they are simple adjusments to p mode as opposed to alternatives so to speak..

manual or M is another kettle of fish entirely.. that really is a different mode.. few automatics work in M mode..

trog
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