How does one stop make such a difference??!!

<p>Hello. So, as I further my studies into exposure, and I just analyze some of my past photos, I am just baffled as to how 1 stop makes such a difference. You can see the difference in color between the two. Is there just a little trick I need to know, or will it just always be this intricate and precise to this extreme? Thanks guys.</p><div></div>

<p>second image</p><div></div>

<p>An increase in exposure by 1 stop = double the amount of light hitting the film/sensor. It is quite a significant difference.</p>

<p>You may want to look elsewhere for this color shift as f/4 to f/4.2 is NOT a one stop difference; not even a half stop difference.</p>

<p>Pete</p>

<p>This should really have been a part of your other thread. Splitting up the same topic like this makes it difficult to offer advice.</p>

<p>First, if your aperture values listed are correct, the difference between f/4 and f/4.2 is not 1 stop.</p>

<p>[[You can see the difference in color between the two]]</p>

<p>This has nothing to do with exposure. I would say it probably has something to do with your choice of auto white balance and your difference in framing between the two. If you're shooting RAW, color correction is so simplistic that one should really not worry about these slight changes. </p>

 

<p>I'd say the difference is largely white balancing. The Auto WB is probably not consistent.</p>

<p>Ok Pete, i'm kinda relieved to hear you say that. Wher else do you think i should look for the problem??</p>

<p>Ok Rob. well i do shoot raw, but i'd like to get the image right the first time, alleviating alot of post processing work. (maybe that's in a perfect world??) and so are you suggesting that since i did reposition my framing, that the camera would'v changed wb choice?</p>

<p>I'll just copy/paste my comment from your other version of this thread, to generally address that topic... though I agree - now that I see your examples - that you weren't actually asking an exposure question as much as a WB question, as Shun points out. As for how one stop (ignoring WB for a moment) <em>can</em> make a visible difference:<br /><br />It all depends on <em>how you come by that one stop</em>.<br /><br />For example: if you leave the shutter speed and aperture alone, and just raise ISO by one stop, you might introduce noise and lose detail. If you gain one stop by opening up a lens's aperture by one stop, you might (it depends on the lens!) lose some contrast and sharpness. If you gain one stop by doubling the amount of time the shutter is open, you might introduce motion blur (in the camera, or by the subject) which robs you of detail and clarity.<br /><br />So (in roughly the same order), you can mitigate the situation by using a camera that tolerates higher ISOs better, by using lenses that still produce sharp, contrasty images when wide open, or by using a camera support (like a tri/monopod) or image stabilization technology when using slower shutter speeds.<br /><br />Or, add <em>more light! </em>Of course, then you have to talk about <em>how</em> you add more light, and whether the quality of that light is helping matters or making them worse (the deer-in-the-headlights strobe-on-the-camera blast, for example, is a high price to pay for more light). Or, shooting at noon instead of at 8:00AM will certainly get you more light, but it will also get you harsh shadows and the need for very high dynamic range.<br /><br />It's all about compromises, and making the ones that best serve (or least get in the way of) the image you wish to create.</p>

<p>Auto WB is just the camera making an educated guess about the nature of the light. So, even a small change in the framing can certainly alter the clues the camera is using to make that guess. It only takes a moment to set up a custom WB when shooting indoors in artificial light, and if you don't want to shoot a WB target and correct after the fact, the custom WB can really help out.</p>

<p>[[and so are you suggesting that since i did reposition my framing, that the camera would'v changed wb choice?]]</p>

<p>Yes. </p>

<p>[[but i'd like to get the image right the first time]]</p>

<p>I don't know your post-processing workflow but I can apply the same WB value to two or two hundred photos with a few mouse clicks. (Some people take a reference shot with a gray card or white balance card and use that frame to apply a WB value to subsequent shots in post production.)</p>

<p>However, you can always turn of Auto White Balance and set it to a specific value when you take the shot. All that means is, instead of doing work in post processing, you'll be doing more work at the time of the shot. There is nothing wrong with that, of course, everyone has their own approach to how they shoot.</p>

<p> </p>

<p>Ah, Matt beat me to the punch.</p>

<p>Ok. thanks so much men :) and OK OK .... so i pretty much repeated my dizzy problem from my other thread ..... what can i say .... i'm just still a newbie all around *wink* - I do appreciate all the help tho guys, as i make my way through (i feel) these final wrinkles b4 i may actually have some type of secure handle on exposure :) </p>

<p>And i do recall learning about taking the gray card shot for future adjustments in post processing. that is one i need to write down right now so that it sticks :) - thank you, that will help alot.</p>

<p>The titles of your shots show exposure difference of f4.0 to f4.2. Is that right, or a typo? That's not one stop. Going from F4.0 up to F5.6, or down to F2.8, would be one stop.</p>

<p>Yeah, sorry, that's right. 4.0 to 4.2 you'll just have to excuse my ignorance of not knowing that wasn't a full stop *blush*</p>

<p>- 0.2 is not 1 stop<br>

- Auto WB could work differently<br>

- SB600 may flashed differently (bouncing angle, recharge, etc.) <br>

- natural light could change outside (if there is a window in a room)</p>

<p>I don't like auto WB because then WB becomes this moving target that I have to adjust for later in post. Are you familiar with the canned WB settings on your camera?</p>

<p>by "canned" do you mean the preset settings?? and yeah, i know em, but i thought auto wb wld b easier, however, i did not know that it could fluctuate like this. so i should reconsider the convenience as an inconvenience perhaps.</p>

<p>also, i had wondered if it had something possible to do with flash also. that's why i had listed it in the photo details. thx for the awareness that the possible lack of recharge?? should be something to consider as well. and i believe there was a small window across the room, but do you think it'd make that much of a difference?? in the color cast? - i really don't know is why i ask :)</p>

<p>Here are the usual aperture full "stops":</p>

<p>1.4, 2, 2.8, 4.0, 5.6, 8.0, 11, 16, 22</p>

<p>Each is double or half it's neighbour's <em>area</em>, ie: let's in twice or half as much light. With most modern slr/dslr cameras showing 1/3 or 1/2 stop increments, it's kind of hard to keep track of the <em>full</em> stops, both for aperture and shutter speeds.</p>

<p>The usual full stop shutter speeds are:</p>

<p>1, 2, 4, 8, 15, 30, 60, 125, 250 and so on.</p>

<p>"1" representing one second, "2" representing 1/2 second, and so on.</p>

<p>well, no one said it before, but i like your picture: you put an interesting angle and composition on what i normally turn into a boring and static scene. now, another thing that's gonna be weird to you: with your sb600 in auto mode, adjusting your aperture is gonna do weird things, like probably nothing at all. the auto program of the sb600 will just kick up the juice to compensate, so you're gonna have a photo with a little more artificial light than natural light. things get weird with auto stuff, and the results are not really repeatable. i wish the flash would show what setting it used, let you dial that in on manual, and go from there. is your sb600 sitting on top of your camera or is it off camera somewhere (if it is not, go to strobist.com and learn why flash is so much fun)</p>

<p>That being said, your comparison is also good for you: you can see tone. Now maybe when you're shooting something, you will set your white balance a little warm like the first one and go for that tone or maybe a cooler wb will set the image in your head to a file. either way, keep having fun, and don't think that any misteps you make have never been performed before you.</p>

<p>ahh, a nice dose of encouragement. thanks Mr. Sutton :) and i have gone to strobist on numerous occasions, but quite honestly, can't get through some of his rambling to grasp the point, lol. maybe it's an anxious personality problem on my account, haha, or maybe i just need to try again. would you suggest anywhere in particular that i go? i've gone to lighting 101.</p>

<p>p.s. Mendel, thank you. i greatly appreciate the lesson on full aperture and shutter stops, i am keeping a note of them :)</p>

<p>well, if your camera has a commander mode, you can pull your sb600 off of your camera and start moving it around, put socks over it to diffuse it, all kinds of fun stuff. i'll bet a good investment is some colored saranwrap (i have never spelled that before so don't think i'm dumb haha). but look at the lighting 102. that's where i started as it seems to get a little more to the point quicker. but there is some good help there, and even if you don't follow the tutorials, it will get you thinking on the right track about artificial light. i need to add an sb600 to complement my sb900 as i think that two lights is when you really get into fun. </p>

<p>now don't think that i'm some old time shooter; i've only been shooting for maybe 5 months. But one book that i've read that has really helped me understand the camera is ansel adam's the negative. you should be able to find this at your library, either school or public. This will teach you everything you'd like to know about exposure from one of the technical masters of photography; adam's style may not be for everyone but his technical prowess was legendary. I cannot advocate this book enough.</p>