The Ask Jake Photography Advice Thread
January 22nd, 2009, 7:31pm by Kelvin
I figured I’d start a thread where we can carry a semi-private conversation with Jake on photography topics. Of course, Jake provided input on Mike and Derrick’s camera choices in previous threads, and helped out picking mine on the sly. Even so, I figure he can be a resource after the purchase as well. Best questions will be compiled as a FAQ.
January 22nd, 2009 at 7:39 pm
Question #1: Would you say that with a proper exposure, you shouldn’t have to adjust levels? I get a lot of pics with blanks in the bright parts of the histogram, especially indoors, even with pattern (full frame) metering. Is that normal? Makes me wonder if my camera is systematically underexposing. Should I routinely shoot with +1 EV? In my limited testing, that often helps fill out the histogram and only rarely causes blown highlights.
Here’s a pair of unaltered pictures, taken with 0 and +0.7 EV.
January 22nd, 2009 at 9:30 pm
Is it OK if I outsource some of these? I’ll ask around, but I’m going with an answer of “no.” The main reason is that you can adjust levels on both the bright side and the dark side. So if you increase your exposure to stretch the histogram to the right (the brightest stuff gets brighter), then you may also shift it so the darkest stuff is too bright.
Now, it might be true that you could always ensure you never have to adjust both levels. But I still don’t think that’s ideal, as there may be other reasons to keep your subject closest to the middle of the middle of the histogram.
Now let me check my answers.
P.S. I had some input on your new camera, too!
January 22nd, 2009 at 9:45 pm
“P.S. I had some input on your new camera, too!”
True, but there’s no evidence of that in the official historical records ;), but I editted the original post to reflect your clandestine contributions.
January 23rd, 2009 at 11:15 am
So I thought a bit about your answer– I guess the main question is what is (or should be) the goal of the metering program? To put the subject in the middle of the histogram? Or to make use of the whole dynamic range available to the sensor? Look at the amount of headroom available on the histogram of this picture, for instance. Almost a third of the histogram is unused on the bright side. On the other hand, the bulk of the information is in the middle. So is this normal or intentional?
Regardless, if you end up adjusting the levels post-processing to stretch the histogram anyway, than clearly, you aren’t getting the resolution you would have if you had increased the exposure in the first place. But I get your other point (one that I hadn’t considered)– a flat image is a flat image, and in this case at least, upping exposure would have increased the brightness of the blacks (hair).
January 23rd, 2009 at 2:11 pm
Well, the truth is that once you start shooting RAW, it doesn’t matter if you underexpose or overexpose by a stop– you can fix that. What does matter, what you can’t change, is the lighting itself. Setting the exposure can only do so much. At some point, the scene needs to be lit properly in order to get the best shot. Here’s a good example of how lighting makes the shot, Make way for reading. If the lighting wasn’t so good, no monkeying with the exposure would fix it, nor would adjusting levels.
So yeah, the correct exposure is important. But it’s more important to get the lighting right to begin with. I realized after 2+ years of heavy photography that ultimately, the only 2 things that really matter in a photo (besides subject) are lighting and composition. Anything else can be fixed with a little post-processing.
January 25th, 2009 at 10:45 am
The idea of shooting in RAW is intimidating (requiring a significant software investment, if nothing else), but I will try to be mindful of lighting and composition. I’ve got a lot to learn about the latter especially.
That said, when you do your processing, do you try for a histogram that’s fully stretched? or keep the subject in the middle? Essentially the same question I asked before– what’s the ideal?
January 25th, 2009 at 2:31 pm
In the histogram, I’ll usually hit auto levels (which stretches the histogram, essentially), and possibly adjust the exposure until it looks good. Getting the face as well-lit as possible without having anything blown out is usually my goal.
I don’t think you need to shoot RAW yet. But you should try some more capable photo editing software. Picnik actually does pretty well (accessible at Picnik.com or via the “edit photo” button above your pics) in giving you more power– you can adjust levels, exposure, do some b/w conversions. There are probably good desktop options, too, but I don’t know what they are.
January 25th, 2009 at 7:45 pm
Windows Photo Gallery has most of the tools that Picnik has, with the exception of the neutral color picker for white balancing, which is a big one. Also, not as many options for color filters (are you a Premium member?). But I think I want to do most of my editting locally. Here’s a pretty comprehensive list of free photo editting software. Maybe I’ll try Picasa, which even supports RAW (at least for viewing, if not editting).
January 28th, 2009 at 5:04 pm
The new iPhoto allows you to pick a neutral color for color cast correction — for all I know, the old one did, too.
January 28th, 2009 at 5:34 pm
How does iPhoto handle RAW, Jake? I read that Picasa will read the raw file, automatically convert to JPG, and any edits you make are on the jpg. You lose all the benefit of shooting raw.
January 29th, 2009 at 1:17 am
iPhoto will open the RAW file & can edit it, but I don’t really know how it works.
And yeah, I think the last 2 versions of iPhoto have had 1-click color correction.
January 30th, 2009 at 10:57 am
I believe this link might answer my question:
Remember that all light meters give you an exposure that would place whatever is covered by it as 18% grey
So the goal of the metering is to make the average grey value 18%– it says nothing about the shape of the histogram. Of course, what we think looks best might have a totally different criteria– like Jake says, as bright as possible without clipping the bright points.
January 30th, 2009 at 12:19 pm
Obviously, an important part of that definition is whatever is covered by [the light meter]. I’m not sure how it works on fancier cameras, but point-and-shoots have various metering modes that range from a central spot to up to 9 areas of the frame. Very important when taking a picture of, say, a person sitting next to a candle.
I’ve always thought that a great innovation in digital cameras would be allowing you to set the metering on one spot, then moving the frame (with the camera keeping track of the set metering level), then focusing and taking the shot. You can already do the reverse (focus on something to set the focal distance by half-pressing the shutter, then recomposing the frame).
January 30th, 2009 at 1:37 pm
I thought how it worked on point-and-shoots is both the focus and exposure locks when you half-press the shutter. At least that’s how it works on my Fuji P/S.
On my Nikon, whether the focus and/or exposure locks with the half-press can be customized, and yes, you can do your light metering on spots, center-weighed, or full frame, just like with point and shoots.
February 13th, 2009 at 12:52 pm
I found a dust spot on my image sensor that needed cleaning… it had probably been there a while, but interestingly, was only noticeable on pictures that were taken with narrow aperture (f > 15). My camera has a cleaning routine that is supposed to shake off dust, but it didn’t work. I ended up blowing off the dust with a squirt of compressed air. Is that a bad idea? What’s the proper way to clean a dirty sensor? I was pretty leery of wiping it off with lens paper.
February 13th, 2009 at 4:46 pm
Just read about cleaning off sensor dust a couple weeks ago at Photojojo. Pretty good article.
Their advice re compressed air:
February 13th, 2009 at 4:48 pm
1) Dust is typically only apparent at small apertures. One of these days I’m going to have to spend 2 hours reading about the physics of photography so I understand why.
2) Blowing off dust is the best method, but don’t use compressed air. Get something like a rocket blower (or turkey baster, I suppose…) and use that. Using compressed air can cause condensation.
3) I’ve used sensor swabs and there cleaning solution (very pure alcohol) when stuff got out of hand. Ditto a lens pen, but that tens to leave residue too.
Best advice– stick to using air until it stops working, then consider using alcohol w/ sensor swabs or Q-tips.
February 13th, 2009 at 5:19 pm
Thanks for the tips and links. Got it, no more compressed air.