Amateur’s Food Photography VI: The Histogram

by Jenn on March 17, 2011

in Photography

Histogram 1

I haven’t done a photography post in a while, but I thought I would get a bit technical with you today and show you something that I started doing not so long ago to help when I take pictures.  This topic isn’t isolated to just food photography either, but can apply to any photo you are trying to create.  When I am taking a photo and trying to figure out the right settings to use, I often rely on reading the histogram associated with each picture in order to assess my exposure.

The exposure of a shot refers to the amount of light your camera let in to capture the image on its sensor.  It does not refer to the amount of light in the room or what is shining on your food.  Controls like ISO, aperture and shutter speed help dictate how much light you want the camera to “see”.  The more light let in to your camera, the brighter a shot will look.  The less light let in to your camera, the darker a shot will look.  I’m not going to get into the specifics of controlling these things today, but instead want to let you know about a valuable tool that you could be using to give yourself instant feedback on the exposure of your shots – the histogram.

When you take a photo and look at it in playback mode on that little screen on the back of your camera, it’s often very hard to see how well the picture came out.  If you are outside in sunshine you’ll probably be lucky if you can see what’s on the screen at all, let alone assess if the image is too bright, too dark, etc.  It’s often frustrating to take a picture thinking it came out great, only to transfer it to your computer later and find out it’s totally dark or bright compared to what you remember seeing it as.  So how does one assess exposure during a shoot?

This is where the histogram comes into play. Most DSLR cameras (and even several point & shoots) these days have the ability to show you the histogram of your shot.  On my camera, when I am in the playback mode, I use the up arrow to display or hide my histogram.   Histograms show a distribution of the brightness of pixels in your photo – on the left side is black, the right side is white, and in the middle is everywhere in between.  Using this information can tell you a lot about how well your camera captured the light of a scene.

However, there is no one shape a histogram should look – as with everything, it depends on the image.  For example, photos with lots of dark regions will have lots of the histogram on the left side, near black:

Screen shot 2011-03-16 at 11.48.43

Photos with lots of bright regions will be the opposite, with lots of the histogram on the right side closer to white:

Screen shot 2011-03-16 at 11.51.20

And photos with lots of midtones, shadows and bright spots will have a histogram with data more spread out across the whole range.  So how does this help figure out if an image is well exposed?

One of the first things I look for when I check a histogram is for clipping.  This is what happens if part of the image is SO far to the left or the right that the data is lost and all you get is pure black or white.  You see this on the histogram because at one (or both) of the edges, will be a giant spike up.  Take for example, this photo of tomato soup (ok, I artificially overexposed it post-processing but it still illustrates the point) -

Screen shot 2011-03-17 at 00.11.52

Do you see how the histogram spikes up on the right side? And if we look at the photo, we can see the garlic in the background is totally blown out.  In this case I think it’s distracting because my eye is drawn to the blown white spot rather than the soup.  If I saw this reviewing the pic in playback mode on my camera, I would retake the shot with a slightly faster shutter speed so that the photo was less exposed.  Regions that are clipped either totally white or totally black in the original exposure cannot be recovered no matter how awesome you are at photoshop – that detail is lost for good.

Some cameras (and some post-processing programs), can even show you exactly where this clipping occurred:

Screen shot 2011-03-17 at 00.12.09

Looking for clipping isn’t the only way to assess exposure.  Here’s a case where the photo I first took was underexposed – meaning it was too dark:

Photographing Roast #5 - Increase exposure

Most of the data is on the way left side, and there’s an actual gap of data on the right – this wasn’t meant to be a dark field image and so this tells me I was underexposed.  Because I checked the histogram in my camera, I was able to figure out that I needed to adjust my shutter speed – to slow it down some to let in more light – the photo on the right shows the histogram for the more exposed photo.  I think I might have adjusted my shutter speed yet again to brighten it even more during that shoot of maple brined pork roast (and now I know the blown spots were on the actually glare on the onions, not from the wall), but these two photos were taken one right after another so I thought were a good example of showing how checking out the histogram during a shoot can help you find the right settings to achieve your desired exposure.

Histograms can also tell you about contrast of an image – here is an image without much contrast:

Screen shot 2011-03-16 at 11.53.03

See how the histogram is squished into a narrow region rather than spread out across the entire tonal range?  It makes sense for this shot, because there really isn’t a lot of contrast in the image.  A high contrast image would have data on both sides of the histogram.  In fact, when you play with the contrast in your editing program, what you are essentially doing is stretching apart or squishing together your histogram to cover a larger or narrower tonal range.

I’ve only given a few broad & general examples here, but the main point I want to highlight is that the histogram is a useful tool to take advantage of.  Understanding what it should look like for your particular shot can help you immensely in determining if you captured the light the way you wanted to.  We’ve discussed in the past about needing good light, but the other part to that is getting your camera to “see” the light the way you want it to :)

Some good links to reading histograms:
Luminous Landscape – Understanding Histograms
Manggy | Special Effects – Understanding Histograms
Matt Wright – Food Photography Post Production

Missed the other posts in the Amateur’s Food Photography series? Check them out here to catch up :)

1 – Look at photos with a critical eye (and making fun of one of my early ones!)
2 - Food photography is about celebrating light
3 – Take your time and find your “zen place”
4 – Angles of Light
5 – Pay Attention to Props

{ 42 comments… read them below or add one }

Shawnda March 17, 2011 at 3:08 am

Great tip! I discovered the histogram display on my camera at Food Blog Camp. The LCD on my camera was actually too dim and when I downloaded all those “perfect” pictures, every single one was overexposed. I upped the brightness on my LCD and started looking at the histogram for a more accurate idea of what the picture would look like imported.

Reply

Jenn March 17, 2011 at 8:19 am

Yes I have done this too, though my problem had been the opposite – what looked “perfect” on my screen was really underexposed – now I can tell much easier by looking at the histogram :)

Reply

branny March 17, 2011 at 3:14 am

Very good information here. I also use the histogram when I’m editing photos in GIMP.

Reply

Jenn March 17, 2011 at 8:20 am

Yes the histogram is also invaluable when editing too!

Reply

Lisa@bakedinmaine.com March 17, 2011 at 4:27 am

I only used the histogram when I edit. Now I’ll do both.. ;)

Thanks Jenn!

Reply

Jenn March 17, 2011 at 8:24 am

Definitely check as you are going, it’s a great way to monitor your shots!

Reply

Rosa March 17, 2011 at 7:52 am

A very interesting post! I’ve been checking my histograms too lately…

Cheers,

Rosa

Reply

Jenn March 17, 2011 at 8:24 am

Thanks Rosa!

Reply

Jeanine March 17, 2011 at 1:20 pm

Great info, Jenn! I love how you have examples for all the different things you’re talking about. Makes it easier to understand. :)

Reply

Jenn March 17, 2011 at 11:09 pm

Thanks, I’m glad all the examples help!

Reply

Maggie March 18, 2011 at 1:22 am

Jenn I should be paying you for these tutorials :) Thank you so much for this info. I’ve got a lot to learn!

Reply

Jenn March 18, 2011 at 7:54 am

haha not at all – I’m just trying to provide little snippets that may help :)

Reply

Rivki Locker (Ordinary Blogger) March 18, 2011 at 1:27 am

I have been noticing the histogram information on my photos, and couldn’t make any sense of it! thanks for this post. Very informative.

Reply

Jenn March 18, 2011 at 7:54 am

You’re welcome! It takes a little bit to figure out at first, but they really are a useful tool.

Reply

Kim - Cook It Allergy Free March 18, 2011 at 6:37 am

Wow! Jenn, this is amazing. I am learning SO much from you. I am with maggie. I feel like I should be paying you. LOL I love how you are providing examples. It is so so helpful. And man, your photos are simply unbelievable. Truly. Thanks for sharing all of this!!

xo
k

Reply

Jenn March 18, 2011 at 7:55 am

Thanks! I’m just glad it helps :)

Reply

Mardi@eatlivetravelwrite March 18, 2011 at 2:20 pm

Great info Jenn and even though it’s a bit techie, it’s still accessible. Well done.

Reply

Jenn March 18, 2011 at 6:35 pm

Thanks Mardi – I’m glad it’s accessible and not too techie :)

Reply

Boulder Locavore March 18, 2011 at 2:32 pm

Fabulous! You are psychic. I have been using Lightroom and the mystery of the histogram has fully eluded me in terms of how to use or leverage it for information (have been paying attention to other things admittedly). I so love this portal into learning about it AND the links for more self study. Thanks Jenn!

Reply

Jenn March 18, 2011 at 6:36 pm

Oh great, I hope this helps you then! Yeah def. check out the links below too, they taught me a lot!

Reply

Karen Harris March 18, 2011 at 3:01 pm

I’ve just retired my P & S and purchased my first DSLR. After spending a week with a handful of props and the owners manual I’m struggling a bit so I am so glad I stumbled upon your blog. Thanks so much for the info. Your examples make is so much easier to understand. I’ll be back!

Reply

Jenn March 18, 2011 at 6:38 pm

Oh great – have fun learning your new camera!! You might also want to check out under the Resources tab at the top, I have a page on photography tutorials of a bunch of links that I’ve collected – some are general DSLR guides that may be useful to you as well…

Reply

Karen Harris March 26, 2011 at 10:56 pm

Thanks so much Jenn, I’ll have a look!

Reply

Kulsum at JourneyKitchen March 18, 2011 at 3:10 pm

Hey Jenn – I have enjoyed reading all the articles in your photography series but this in particular I have found very informative. I always wondered about histogram and even though I knew what its purpose is but never thought I would use it. This article changed my mind. Thank you!

Reply

Jenn March 18, 2011 at 6:52 pm

Thanks – let me know how it goes as you start using it, I hope you find it helps you!

Reply

Lindsay March 18, 2011 at 4:48 pm

Super tips! I’m still getting used to food photography so I can’t wait to get home and look at my histograms!

Reply

Jenn March 18, 2011 at 6:53 pm

It was really eye-opening when I started paying attention to them too, they’re such a great tool!

Reply

Simone March 18, 2011 at 5:17 pm

Very useful article Jenn! I am sure a lot of people can use this information. When I give a workshop it also one of the things I try to explain on how to use the histogram. It makes so much sense!

Reply

Jenn March 18, 2011 at 6:55 pm

Thanks Simone – I can’t believe how long it took me to get into the habit of using it rather than just trusting how an image looked on the back of my camera – ever since I started checking my histogram in-camera, I’ve had much better success getting my exposure how I want it, it was so enlightening when I realized exactly how useful it is :)

Reply

Jean | Delightful Repast March 19, 2011 at 8:29 pm

Thank you, Jenn, for this great series. This one, part six, is a bit technically advanced for me; but eventually I’ll be ready for it. I didn’t realize when I started food blogging how intrigued with food photography I’d become. A year later I’m thinking about camera upgrades.

Reply

Jenn March 20, 2011 at 8:04 pm

Thanks – I’m sorry this post was too advanced, I promise the next one won’t be so technical – but when you are ready to learn about histograms, I hope that this post or the links at the end of it will be helpful :)

Reply

Jackie Baisa March 21, 2011 at 10:08 am

When I took a wedding photography workshop in Canada a couple of years ago, the instructors taught us to actually SHOOT using the histogram on the back of our camera (instead of relying on what the image looked like). That was quite a fantastic revelation. You could still see the photo you just shot, but it was smaller, and there was a histogram next to it. Shooting weddings, you usually have quite a bit of a contract between a white dress and a black suit (and other colors in-between) so it really works well to pay attention to your histogram. I haven’t done that for a while, though. But I do use it in Lightroom!

So, you got Lightroom then?! YAY!

Reply

Jenn March 21, 2011 at 9:58 pm

:)

I totally agree, shooting using the histogram was about a life-changing for me as learning to shoot tethered – probably more-so in fact!

Reply

Carla @ Gluten Free Recipe Box March 28, 2011 at 5:08 am

Any suggestions on a good camera for gluten-free blogging recipes? Mine just broke when dropped. :-(

Reply

Jenn March 28, 2011 at 5:20 am

Oh no, sorry to hear about your camera! However, I’m not really qualified to give equipment recommendations. Many other food bloggers and experts have talked about the equipment they use and why they love theirs – on my food photography tutorials page, there is a list of posts by subject, and you might like to check out what some other bloggers use by checking out the links under “gear and settings”.

Reply

Sophie April 6, 2011 at 10:19 am

Thank you so much for this tutorial!! I was impressed. My husband is a keen photographer & he explained a lot to me too!

You are a great & good teacher to us all!

Reply

Jenn April 6, 2011 at 8:43 pm

You’re welcome Sophie!

Reply

Vicky February 28, 2012 at 9:25 pm

Great advice! I can honestly say I’ve never paid any attention to the histogram in the camera — but now I sure will!

Reply

Jenn February 29, 2012 at 9:35 am

Great! I’m glad it’s helpful!

Reply

kelly @ kellybakes September 14, 2012 at 2:49 am

I just got my DSLR in July so I’m trying to learn more about photography, but get overwhelmed reading books on it. Thank you for explaining the histogram so clearly. I had a very vague idea as to how it worked, but you made it make a whole lot more sense. Thanks for a great piece–I’ll definitely be checking out the rest of your photography posts!

Reply

Jenn September 14, 2012 at 8:12 am

Wonderful! Glad to hear that it’s clear and helpful!

Reply

polly March 16, 2013 at 7:51 pm

Awesome post. So lucid and intelligible. Thank you, Jen.
polly

Reply

Leave a Comment

{ 1 trackback }

Previous post:

Next post: