Entries Tagged 'Photography' ↓

Overbooked

I love books. As much as I’m immersed in technology and want to be green, there is something about holding a physical book that has yet to be rivaled by electronic book-like creations. I have a theory that college life gets you accustomed to lugging around big books and, more relevant, to reading more than one book at a time. I’ve gotten several books in the last couple of weeks (adding to my tall stack of books with active bookmarks in them) and here are my initial thoughts about them.

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Photoshoot: Butterscotch Cashew Bars

Butterscotch Cashew Bars

I enjoy reading how other photographers setup their shoots to get specific photos, so I thought I’d start a series of “Photoshoot” posts each describing the setup to get one of my shots. These Butterscotch Cashew Bars are featured at Bake or Break.

This type of shot that washes out in highlights in the distance is popular on food blogs and hardcopy publications, as well. In this case, four similarly sized bars are lined up along the camera axis and shot down from a shallow angle. The final shot was taken with a Nikon D200 through a 60mm macro lens (f11, 1/3s, ISO100).

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Blog Exposures

Here are some recent photography related posts from around the net that I’ve read all the way through (my tried and true measure of post goodness).

The dirty tricks of food photographers – Photocritic blog explains some of the tricks of the food stylist’s trade, ways to make food look it’s best. This has absolutely nothing to do with making it taste it’s best, or even making it edible or, in some cases, non-toxic. It’s a little like a magician telling you how they do their magic, though, so if you are easily devastated, maybe skip this one.

Welcome to “Lighting Gear Week” – Scott Kelby, the reigning king of photography education, kicks off a week of posts related to photographic lighting. Since many of the two or so questions each week I get asked about are lighting related, I know he must be inundated by such questions and I’m looking forward to reading the rest of these posts. On this first day’s post, Scott describes the setup for a budding wedding and portraiture photographer on a budget. His advice is bang on in my book.

6 Tips for Perfect Composition in Portrait Photography – This guest post by Christina Dickson at Digital Photography School offers some useful insights into portrait composition. Sensationalized title aside, the article provides some simple ideas and example images, things that can improve your photographs and keep them fresh.

Photoshop Lab Color Enhancements: NYC from Above

NYC from Above - After

Here’s a doosie. This image is dismal, normally a throw away shot that should never be shown to anyone. Ever. Under any circumstance.

But…

I love New York, I really do, and, well, when I took this pict… I mean, when the anonymous photographer took this picture, he or she wasn’t really sure if it the little point and shoot camera was considered an “approved electronic device” and, well, at this point of approach, none are. So it’s barely in focus, the settings on the camera are what they were for the last picture taken, there was only time for one or two shots, so the composition is.. well.. there’s a huge wing in frame. But it’s NYC and since the pilot probably wouldn’t have taken kindly to a request to loop back around for a better shot, this is what we’ve got to work with. It’s a lousy picture, but Lab colorspace enhancements really rock with pictures like this: unsaturated, hazy, snoozy. Let’s see what we can do with it.

You can download the original from flickr by clicking here to play along with the image if you want. The best way to get comfortable with Lab maneuvers is to play with them. Once opened in Photoshop (the images below are from CS3 but should be similar in CS2), convert the image to Lab mode (Image -> Mode -> Lab Color). I’m only showing a cropped section of the whole image to show more detail. Here’s the starting version:

Image before any adjustment

The first change I made was a Levels adjustment in the Lightness channel (Layers -> New Adjustment Layer -> Levels…). There are three sliders right under the histogram that can be repositioned to set the black point, gray point, and white point.

Levels settings

The far left slider represents the black point (and is conveniently filled in black). I slid this over to 48. This setting cut into the mass of the histogram a little, which is generally bad as it causes clipping, but shadow clipping is a lesser offense than highlight clipping and this image was so bad to start with, it didn’t really hurt much. The far right slider (filled in white) sets the white point and I slid it over to 238 (it started at 255) careful not to cause substantial clipping in this case. The gray point slider behaves differently and adjusts the overall lightness. Sliding it to the left will lighten the image, to the right will darken it. I slid it to the right to 0.90 which looked best to my eye.

It’s mildly interesting to note that changing the levels on the Lightness channel are not actually setting the white and black points of the overall image as they would be in an RGB channel levels adjustment. They are setting the points of maximum and minimum lightness for the overall image. In reality, they are actually setting the white and black points for the Lightness channel which looks like a black and white version of the image. This is just a minor point that has probably overly complicated the discussion, so I’ll stop while I’m behind. Here’s what the image looks like after the Levels change:

Image after Levels adjustment

At this point, the image is already looking a littler better, but the real magic of Lab adjustments come from Curves. In this case, I didn’t flatten the image at this point so that I could go back and tweak the Levels settings later if I wanted to. Create a new Curves adjustment layer (Layer -> New Adjustment Layer -> Curves…). Here are the Curves settings I ended up with (and the unsharp mask settings which I’ll get to later) — I’ll discuss each in turn.

Curves settings

The top right “a” channel curve is a simple steepening of the curve, like turning up the gain. The curve passes through the origin (center point) of the graph so there is no shift in the color cast in this channel. Since the “a” channel represents magenta to green colors, these will be intensified a bit by this curve. The points I chose were +/- 77 (as you grab the little squares in the corners and move them around the curves area, the Input value will change).

A little more interesting magic happens in top left “b” channel curve. In this case, we don’t pass through the origin, instead passing a good bit to the right of center. I could have done some white balancing in a number of ways with this image, but I chose to remove the dingy yellow cast in the original image through the Lab “b” curve. A good way to get familiar with Lab and an excellent way to remove color casts using it is to observe the Info helper (Window -> Info or F8) as you move the mouse over the image. For the pixel currently under the mouse, the Info helper will show the L, a, and b values. A color neutral value anywhere from white through gray to black should have a and b values of zero. If you identify some elements in the image that should be white or true gray (in this case I chose parts of the wing that I didn’t feel were reflecting blue sky), mouse over them and observe the a and b values. In this case, the b values were consistently around 8 when I thought they should have been 0 and the a values were close to 0. I ended up with values of -77 and +92 for the endpoints of the b curve.

The Lightness channel curve is generally used to add some contrast to the image and I like to change it after making the color corrections. In this case, I used a fairly subtle contrast enhancement S-curve. The premise here is to increase the slope of the curve where you want additional contrast. There will be better images that we’ll examine in the future to show how to judge this adjustment, so we’ll patiently wait for now. Clicking OK saves the Curves settings and we see:

Final enhancements

Without any exceptions (only when there are exceptions), all images deserve sharpening. This is to say that most images look better after they’ve been sharpened. A better (and less sarcastic) absolute is that no image should ever, ever, under any circumstance (well, maybe a few interesting ones that we’ll also discuss in the future) should sharpening be applied to color channels, only Lightness or Luminosity. If you are in Lab already, it makes sense to apply the sharpening to the L channel.

Press command-1 (on a Mac, or Ctrl-1 on a PC?) and only the L channel will be displayed, looking much like a black and white version of the image. Anything you do with Photoshop at this point will only be applied to the L channel. In this case we want to use Unsharp Mask (Filter -> Sharpen -> Unsharp Mask). I used some mild sharpening settings as shown in the lower right of the figure above. After OKing these settings, pressing Command-` (Ctrl-` on PC?) brings back the composite image. At this point all that is left is to switch back to RGB, or CMYK if that’s what we need to do (Image -> Mode -> RGB) and we’ve got our final image:

NYC from Above - After

It’s still not a great photo, but I would definitely not be nearly as devastated showing someone the final version. Lab color enhancements are not appropriate for every image, but this is an example of one in which Lab really shines. Images that already have a lot of saturation or vibrant colors are not going to be helped by the steeper a and b channel move here and may produce colors that can’t be printed or viewed on a monitor. But if you have a desaturated, color starved image, this simple enhancement process can make a huge difference. If you play along with the image in Photoshop yourself, the differences in the image at each step really pop, but seeing them one at a time and having to scroll a window up and down to see the different stages don’t do it justice. So in parting, here’s a before and after composite of this enhancement:

Lab color enhancement preview, before and after

Death by Chocolate

Chocolate Mascarpone Brownies

Are there any other chocolate groupies out there? If you have a weakness for cacao like I do, then check out my sweet wife’s Chocolate Mascarpone Brownies on her baking blog Bake or Break.

If you think it’s worthy, cast your vote for it in the Death by Chocolate contest hosted by Culinate. Here’s the best part, if you vote, you’ll be entered to win as well. What could you win, you ask? The same thing as the victor in the blogger category, a weekend in Napa, California, to attend the annual Death by Chocolate Festival. There are also daily prizes — read all the details here.

Photoshop CS3 Lab Color Enhancement: Central Park Wysteria

Here’s another example of an image quickly improved by enhancements and sharpening in the Lab color space. This shot was taken in Central Park of a wysteria vine that had taken on tree-like proportions. All I had with me was a small point-and-shoot and we were in a bit of a hurry, so I just snapped the picture letting the camera do everything. In just a couple of minutes playing/working in Lab Color made a substantial difference. The result is an image that has much stronger colors and makes me happier to look at. Here’s a swatch of the original image:

I started by converting the image into Lab (Image -> Mode -> Lab Color). From here I created a new curves adjustment layer (Layer -> New Adjustment Layer -> Curves…). I usually start by adjusting the ‘b’ channel first. This allows me to white balance the image as the ‘b’ channel is responsible for the blue to yellow range of colors. A negative ‘b’ means a blueish cast.

If you have the Info window open (Window -> Info) you can see the L, a, and b values of the point under your cursor. As you mouse over an image, if there are areas that you know should be colorless (white, grey, or black) you can check the ‘b’ values. If there is a consistent negative ‘b’ value in these areas, you can use the ‘b’ channel curves adjustment to remove it. Shifting this curve to the left (as I have my curves setup) will remove the blue cast. Here is the ‘b’ channel curve that I used:

In the case of this image, I didn’t feel that there was any white balancing necessary, so I simply steepened the ‘b’ curve by brining the end points in the same amount (+/-99). A similar curve in the ‘a’ channel results in a good starting correction curve pair for working in Lab. I have a few variations of these curves saved as presets which make them easier to use. To save a preset, click the small box between the Preset pulldown menu and the OK button in the Curves window, select Save Preset… and give your preset a name. I use ‘Lab simple ab95′ as the name of curves that pull the endpoints of both ‘a’ and ‘b’ channels to +/-95, for example. Here’s the ‘a’ curve for this correction:

These two adjustments result in this:

At this point the colors are more vibrant and the image is starting to look better. There’s still more that we can do to help it, though. A little bit of contrast helps many images, so this is the ‘L’ channel curve I used:

Resulting in a slightly more contrasty image with a little more separation between the shadows under the limbs and in the leaves:

At this point, I usually flatten the image and do some sharpening and call it a day, but I felt like I could do more with this image. In particular, I though the colors of the blossoms could be bluer. In RGB, this could be done, but at the expense of causing everything to take on a blue tint. In Lab, it’s very simple to make an adjustment that affects one part of an image that is at an extreme of one of the a/b channels. In this case, the ‘b’ channel is much darker in the blossom area than anywhere else. We can use this in a mask to affect changes selectively.

I clicked on the layer mask icon (starts out as a white rectangle between the curves icon and the text ‘Curves 1′ in the list of layers) to highlight it (it gets little corners outside the rectangle when it is selected. I clicked Image -> Apply Image… to bring up this dialog box:

I set the Layer from which to apply to Background and set the Channel to ‘b’ so that the ‘b’ channel of the original image (before any color correction) is used as the mask. I also set the blending mode to Multiply from Normal which has a dramatic effect on the image. When these steps are done, the resulting layers display looks like this:

Note the changes in the layer mask from a white rectangle to the varied grey version. I lowered the opacity to 60% to see the effect, but ultimately raised it to 90%. While I made this move to improve the blue flowers, the multiply blending strengthened the green leaf colors and darkening the image overall. However, comparing the blossoms before and after, they retain much of their brightness while adding some blue tint. This wasn’t exactly where I was heading, but I liked it when I got there. Here’s where we are now:

Whenever using a layer mask in this manner, it is best to blur the mask. It seems wrong, but the results are always so right. With the layer mask still selected, click Filter -> Blur -> Gaussian Blur… to get to this dialog:

A blur of 20 pixels is a reasonable choice most of the time, although it’s really only necessary to blur to the point at which the details in the mask layer are lost and only soft shapes remain. After applying the gaussian blur to the layer mask, we get:

From this point, I flattened the image. If you are in Lab Color, it is definitely best to do any sharpening before leaving the Lab. Switching over to the Lightness (L) channel before sharpening means that only this channel will be affected. Since the L channel contains the detail of the image, it is the optimal place to sharpen without risking color aberrations (which are really evident when sharpening in RGB without applying it to the image luminance). Pressing CMD-1 on a Mac (or some equivalent on a PC.. ALT?) will show the L channel (it looks like a black and white version of the image):

Using our old friend Unsharp Mask (Filter -> Sharpen -> Unsharp Mask…) with these conservative values:

results in the following sharpened image:

Putting it all together, we went from this (click through to see a bigger version at flickr):

Central Park wysteria - original before Lab color enhancement

to this:

Central Park wysteria - after Lab color enhancement

Lab experiments: Basic Lab color space enhancement in Photoshop CS3

I’ve been thinking back on my early days of photography, Tri-X black and white film developed in a closet converted to darkroom near my bedroom as a 7th grader. Fortunately for my parents, both were isolated in the basement of our house so the aromas were fairly contained. The process required to transform photons to prints was staggering in comparison to today’s digital workflows and my passion for it had to be fueled by youth.. and no alternative. Given the capabilities today, I can’t imagine spending hours in a safelight lit room, although when I get a whiff of vinegar, I’m still transported back in time to that little closet.

Recently, I’ve been experimenting in Lab, the color space, not the kind with test tubes and/or monkeys. I had heard a few buddies talking about Lab before but had never dipped a toe. Then someone was brave enough to show me his before pictures and an example of the adjustment process. The combination of the ease with which the adjustments were made and the dramatic results floored me and I could resist no longer. My first experiment with Lab was a huge success and since then I’ve been playing with old photos in my spare time (actually little mental health breaks from coding). I’ve been meaning to blog about some of my experiences and haven’t had the time, but I’m facing down a particularly ornery bug and I needed a break.

I’ll give you this warning now: once you start playing with color adjustments in Lab, you’ll feel really sad that you’ve shown people some of your photographs, even those you’re most proud of.

These are the steps I used to convert this picture from a recent hike that David and I took near Durham. The original photo warranted three stars in my Aperture library. It’s not a great picture, but I thought the colors were attractive and the composition somewhat interesting. The image looks a little flat and dull. Here is a cropped section of the original image:

Before anything

I opened the image in Photoshop CS3 and converted the image to Lab with Image -> Mode -> Lab Color. I created a new Curves adjustment layer (you can do this through the menus with Layer -> New Adjustment Layer -> Curves… or with a shortcut by clicking on the “Create new fill or adjustment layer” button at the bottom of the Layers panel (it looks like a half white/half black circle) as shown below and selecting Curves… from the pop-up menu.

Given that the original image seemed to have an overall blue cast to it so I started with the b channel adjustments by selecting ‘b’ in the channel pulldown menu in the Curves adjustment window. Lacking any known source of white or gray in the image, I used my best judgment. With a white balanced image, the normal a and b channel adjustments pull in the left and right corner points the same amount such that the line pass through the origin of the curves graph. As you play with the b channel, you’ll see that shifting the curve to the left (as I have my Curves setup, to the left if you have yours setup in the CMKY mentality) reduces the blue cast of the image.

b channel adjustment

Here’s the result of this adjustment:

Leaves after b channel adjustment

At this point the colors are warmer and the blue cast is reduced. Some may say I’ve gone too far, other may say not enough. On this day, with my laptop screen and nice overcast light coming in through the windows behind me, it looks better than it did and better than more or less as I played with it. Now on to the a channel.

a channel adjustment

The a channel curve is a more traditional Lab color enhancement curve in that it passes through the origin. The purpose of this change is to create a steepening of the curve as it passes through the values in use, essentially the same as what we do when adding contrast to the lightness channel. The corner points can be pulled in different amounts depending on the amount of adjustment desired and your mood that day, so it’s good to play with them. The amount I show here is a moderate, average adjustment in my experience. Remember that you can always tweak the adjustment with the layer opacity later, so even if it looks a little too strong, you can tame it down later. Here’s the result of the a channel adjustment:

Leaves after a channel adjustment

As I’ve been working my way backwards through the channels in Lab, the Lightness channel is the third and final that I adjusted. This channel contains no color information, only, well, lightness, and if you look at this channel on it’s own (command 1 on a Mac.. any Windows users willing to let us know what it would be on a PC?) it looks like a black and white version of the image (command ` will get you back to normal).

Lightness channel adjustment

In the Lightness channel, I only did a minor contrast enhancement S-curve. This alters the image in a similar way that a normal RGB-channel curve like this would. Here’s the final result of the color enhancement:

Leaves after Lightness channel adjustment

I flattened the image (Layer -> Flatten Image) and converted the image back to RGB (Image -> Mode -> RGB) and applied a light sharpening to the image using Filter -> Sharpen -> Unsharp Mask… using these settings:

unsharp mask

As always when sharpening in RGB, it’s important to apply the sharpening to the Luminosity channel, not the color channels. To do this, immediately after using unsharp mask, select Edit -> Fade Unsharp Mask… and select Luminosity from the pulldown menu:

unsharp mask luminocity

Here are the pre- and post-enhancement images for reference. Click through each to Flickr to see larger versions.

leaves before

leaves after

The adjustments definitely have an effect on the final image. The sickly blue haze has been lifted and the colors are more vibrant. This is certainly not the most dramatic effect I’ve experienced when working with Lab color enhancements. In fact, this and other Lab techniques can resurrect images that RGB approaches can’t help and would otherwise be fitting only for the delete key. In this example, I believe that an okay photo was improved, and that’s what matters.

The Lab color space is fundamentally different than RGB or CMYK which is why some of the magical color enhancements that take seconds to perform in Lab are impossible or extremely difficult in RGB/CMYK. If you’ve never played with Lab, it’s well worth the time. And if you remember the smells of darkroom chemicals, it’s interesting to consider how unimaginable things like Lab adjustments were back in the day. If there is interest, I’ll continue posting examples of image enhancements that I do using Lab over time. I’d also like to explore other software that is capable of working in Lab since not everyone is willing to splurge for Photoshop. If you’ve used other Lab-worthy software, please drop a note in the comments and let us know what it is.

Does My Blog Look Good in This?

If you are an aspiring food blogger, or just like drooling over pretty pictures of food, check out this month’s DMBLGIT on Jennifer’s blog Bake or Break. The hard-to-say acronym stands for “Does My Blog Look Good in This?” and is a chance for foodies to show their best picture of each month to the world.

As this is her first time hosting DMBLGIT, she has gone all out and looked at alternative hosting for the submitted images. Smug Mug turned out to have the nicest looking albums for displaying image groups of all the sites considered. I’m a big fan of flickr, and so is Jennifer, but we agreed that it didn’t work for this purpose for two reasons: images imported for display in a set would end up in her photostream, which seemed wrong, and flickr lacks some pizazz. Less is more in the pizazz category, as with other categories, but none is, well, still none. Anyway, you can see this month’s gallery of DMBLGIT at Smug Mug.  And if you have a food blog with a picture you’re proud of from September, there is still time to enter.

Happy (half-)Birthday, Bake or Break!

My wife’s blog Bake or Break is 6 months old today. It’s hard to believe.. the time has gone by so quickly. If you haven’t visited there before, the subtitle of her blog is “Adventures of an Amateur Baker” and it features many things, all baked, and all delicious (except for things with coconut, but that’s just me). She has accumulated over 70 posts, all but a couple featuring something she has created including her description, the recipe or a link to one, and one or more photographs.

Here are some of my favorite memories from the site:

Limoncello Cheesecake Squares

Alton Brown Pizza

Chewy Chocolate Cookies

Chewy Graham Brownies

Outrageous Peanut Butter Cookies

Paula Deen's Basic Biscuits

Mini Cheesecakes

Mini Pecan Pies

Apple provides free Aperture test drive

Apple is providing a test drive of their (totally awesome) Aperture application for photographers.  Click here to receive your free 30-day license.  Apple describes Aperture as:

The first all-in-one post-production tool for serious photographers, Aperture provides everything you need for after the shoot. Using its comprehensive collection of tools, you can easily import, manage, edit, catalog, organize, adjust, publish, export, and archive your images more effectively and efficiently than ever before.

I’ve been using it for about 6 weeks and I adore it.  It has a steep learning curve, but it has more customizability than any other photo application I’ve used.  I’ll be writing some recipes on it once I feel that I’ve mastered some of the capabilities well enough.

So, if you have a Mac and a camera and are serious about your photographs, give it a spin!