Food Photography Tip of the Week |11|

What the heck is ISO?

ISO is your camera’s [specifically—the image sensor] sensitivity to light.

// the lower the ISO –> less sensitivity to light –> finer grain in the photo –> smoother quality –> darker the image

// the higher the ISO –> more sensitivity to light –> rougher grain in the photo –> noisier quality –> brighter the image

To achieve the highest quality image you want to keep your ISO as low as possible, while maintaining proper exposure and sharp image quality. The higher you set your ISO the brighter your image will become, but at the same time the photo quality will degrade and create “noise” – graininess.

Note: as you increase your ISO your photo will not become blurry, a common misconception. Photo blur has to do with not using a fast enough shutter speed, not ISO.

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So why would you ever want to increase your ISO past the lowest setting of 100 if the image quality is going to degrade? ----> Although with each increase it’s true that more grain will be present, there is a certain threshold [varies by camera model] you can increase your ISO to where you won’t notice the noise unless you zoom far in or blow up the image to a very large size. If you’re just using the images for your blog you’ll have more play since the photos are displayed at a fairly small size.

Note: Every camera has different ISO capabilities. The higher quality the camera the higher you’ll be able to set the ISO without seeing noise. You’ll also have a wider range of ISO setting options with higher quality cameras.

For instance:

Canon Rebel xti – ISO options: 100, 200, 400, 800, 1600 – I liked to keep this camera at 400 or below. It was usable at 800 but not preferred. At 1600 the image very noisy.
Canon 7d – ISO options: 100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 100, 1250, 1600, 2000, 2500, 3200, 4000, 5000, 6400 – I like to keep it under 1250 for the photos on this blog, but 1600 + 2000 are usable. I’ve increased it higher when going for a specific grainy look or trying to take people photos in low light when I don’t want to use my flash.

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So in what type of situation would you need to increase your ISO?

You’re shooting in low light and can’t reduce your shutter any further without creating a blurry image. Here you can increase your ISO, decrease your aperture, or a combination of both to properly expose the photo.
Your aperture/f-stop is at the exact depth you want, you can’t slow your shutter speed any further, but your image is still underexposed. Increasing your ISO is the only option here.
You want to create grain in your image to achieve a particular artistic look.

Increasing your ISO will allow you to shoot with a faster shutter speed and/or widen your depth of field. ISO, shutter speed, and aperture all work together to create a properly exposed image. If your shutter + aperture are dialed in exactly how you want but your image is underexposed your next option is to increase ISO.

Are you using a tripod? If so, there’s a good chance you’ll be able to keep your ISO pretty low since you can slow your shutter way down without experiencing camera shake/blur. But if you’re hand-holding and in low light you’ll probably want to play with increasing your ISO.

Note: There are some editing tricks in Lightroom [and Photoshop I’m sure, too] for decreasing noise when having to use a higher ISO.

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In the first 5 photos below I’m going to show you how changing only the ISO affects the photos. Watch the f-stop + shutter speed stay the same but the ISO increases to further expose the photo.

I wanted to keep it really simple with the photo subject.

above: f/2.8, SS 1/100, ISO 100 – highly underexposed

below: f/2.8, SS 1/100, ISO 200 – slightly underexposed

above: f/2.8, SS 1/100, ISO 320 – properly exposed

below: f/2.8, SS 1/100, ISO 500 – over exposed

below: f/2.8, SS 1/100, ISO 800 – highly overexposed

In the next photo set I’m increasing ISO while also changing the shutter speed to compensate for the increased ISO and create a properly exposed photo. You’ll start to see noise in the image as the ISO increases.

This is simply to show how increasing your ISO creates noise and degrades the image quality.

above: f/2.8, SS 1/80, ISO 200 – No visible noise.

below: f/2.8, SS 1/250, ISO 800 – At ISO 800 there is really no detection of noise when the photo is displayed at this size for the blog.

above: f/2.8, SS 1/500, ISO 1600 – You can start to see a bit of noise present but it’s not too noticeable at this size. If you printed the photo to a larger size you would see more of the noise.

below: f/2.8, SS 1/2500, ISO 6400 – This is my camera’s highest ISO setting and the noise is now very noticeable even at this small size.

An up close look at the 4 images above zoomed in by 75%. At ISO 800 the image is still fairly noise-free but you really notice the degradation at 1600.

Hopefully this gave you a better understanding of the ISO function on your camera. I always find it slightly difficult to explain shutter/aperture/ISO because they all work together to create the look you want with proper exposure.

Feel free to ask questions in the comments!

Ashley

Food Photography Tip of the Week |10|

Let’s capture motion: powdered sugar edition

Last week got a little wordy, so I want to keep today’s lesson simple + fun. It’s really all about getting your set up dialed in before you start and then playing with your shutter speed. Let’s get started!

1. Get your shot set up. I know this seems like common sense but you really want your food to be positioned just right so you don’t have to adjust it once you start adding the powdered sugar element. Take a few test shots and make sure it’s what you’re going for. Also get your background, surface, light bounces, etc. in position.

2. Use a contrasting background color. The darker your background the more the powdered sugar will show up. However, if you want the powdered sugar to be really subtle you’ll want to use a light background color.

3. Use a tripod. There is no possible way you can hold a camera while sprinkling powdered sugar on doughnuts/cake/brownies/etc. and actually click the shutter to take the photo. Unless you have super powers.

4. Use a remote shutter. This is not 100% necessary, as the last 2 photos were not taken using one. However, it makes this task [and pour shots, etc.] much easier to pull off. This is the remote shutter [only $17] I use. All you have to do is plug it in then start snapping. Using a remote shutter allows you to stand right next to the food so you can sprinkle the powdered sugar with one hand while holding the shutter in the other and clicking to capture the image. Without a remote shutter, you’ll have to sprinkle with one hand and stretch your arm to your camera’s shutter to click at the same time.

5. For a powerful image shoot straight on + stack your food. Shooting straight on while stacking a few of your baked goods [unless it’s tall like layered cake] will create a lot of impact in your image and help to fill up the vertical space. You’ll feel as though you can really pluck the food straight from the screen, as it’s a bit more “in your face.”

6. Shoot vertically. This allows you room to stack the food and also leaving enough space for a long stream of powdered sugar. It also helps to create a more powerful image.

7. Shutter speed controls the powdered sugar movement. The faster the shutter the more “frozen” the powdered sugar will appear. The slower the shutter the more blurred the movement will be. Play around with the shutter speed while keeping the photo properly exposed until you reach the exact look you want.

8. Decide where your focus will be. Typically, in straight on shots like this you want to focus on the closest part of the image to the lens. For instance, I focused on the strawberry lemon curd oozing from the top doughnut in the 4 photos below.

9. Decide on your depth of field. I like to keep a fairly shallow depth of field so the focus is on the front of the doughnuts with the powdered sugar fading behind.

10. Get a mini mesh strainer or powdered sugar shaker. This is what you’ll use to achieve even shower of powdered sugar.

Time for a few examples so you can see what kind of settings I used and how they affect the motion in the image.

above: (35mm 1.2L lens) ISO 2000, f/3.2, SS 1/1250

In the above + below images I used a very fast shutter to create more definition in the powdered sugar and more clearly freeze the motion. The blurred specks are due to the shallow depth of field. If I wanted the specks more in focus I would widen my depth of field [larger number].

In the photo above I lightly tapped the strainer while in the photo below I gave it a harder shake.

below: (35mm 1.2L lens) ISO 2000, f/3.2, SS 1/1250

above: (35mm 1.2L lens) ISO 640, f/3.5, SS 1/400

In the image above I slowed the shutter speed by over half but it was still pretty face. The specks of powdered sugar lengthened because more of the motion was captured while the photo was being taken. The slower the shutter the more movement/motion you’ll see.

I decided I liked the more defined powdered sugar specks and went back to the 1/1250 speed. In the photo below I moved my hand to try and have powdered sugar falling in the background of the entire image. Like I said, it’s all about experimentation!

below: (35mm 1.2L lens) ISO 2000, f/3.5, SS 1/1250

above: (50mm 1.4 lens) ISO 1000, f/3.5, SS 1/250

In the photo above you’ll notice a much bigger blur to the powdered sugar in comparison to the first 4 photos. However, I felt the powdered sugar looked too blurred at this speed. I much prefer the image below which was taken at an even slower shutter speed of 1/80. The powdered sugar has a softer feel with more of an even look, while in the photo above it’s a bit harsher. The motion has less of that “blur” feel and presents more as smooth movement.

These shots were created for the cover of my doughnut cookbook and the image below was the final shot!

below: (50mm 1.4 lens) ISO 640, f/4.0, SS 1/80