Shooting Tips for 1" Sensor Cameras

Shot with a Sony RX100iii

The 1" sensor camera segment is on fire! It's easy to see why. They're are fun, affordable, portable and offer a big jump in image quality over a cell phone. There is something for everybody in these little cameras. They work well as high quality point and shoots. The compact models can fit in a pocket or purse. And because they have manual controls, enthusiasts love them as grab and go cameras that don't require a backpack full of lenses.

Nikon recently announced three new "DL" models representing three ranges of (equivalent) focal lengths: 18-50mm, 24-85mm and 24-500mm superzoom. (Why change lenses when you could just change cameras?) Canon has the GX-3, GX-5, GX-7 and GX-9 cameras. Sony has the RX100 and RX10 cameras that are very popular. Finally Panasonic makes the DMC-ZS100/TZ100 and the FZ1000 superzoom.

A "one inch" sensor is not actually an inch in diagonal. It's called a one inch sensor because it replaced the old one inch diameter cathode-ray tube in video cameras. The chip actually measures 13.2mm by 8.8mm (15.86mm diagonal) or about half the surface area of a micro four thirds sensor. Doing the math, the crop factor comes out to 2.7. The secrets to getting good images are to avoid diffraction effects, and give those small pixels plenty of light. But what exactly does that mean? Don't worry, these will be explained in the following paragraphs.

Keep the f-stop low, below f/5

When light passes by an obstacle like the aperture blades in a lens, some of the light is scattered due to diffraction. As the aperture gets smaller, this scattered light starts to blur the image. Diffraction has more of an effect on smaller pixels. For the size of pixels in these cameras, diffraction begins to negatively affect the sharpness around f/5, and by f/11 the image is noticeable blurry. To see this effect, look at the images below. Cambridge In Color has a calculator for finding the diffraction limit for different cameras. ( http://www.cambridgeincolour.com/tutorials/diffraction-photography-2.htm )

In general, it's good to keep the f-stop low because it lets more light onto the chip. On a full frame camera, shooting at f/1.8 would mean having a razor thin depth of field. Shooting a portrait with this f-stop might mean getting one eye in focus and the other eye blurry. But with a cropped sensor camera, you multiply the f-stop by the crop factor of 2.7. So in this case, 1.8 x 2.7 gives a full-frame equivalent of about f/5.

Here is a table of equivalent f-stops:

f/1.8 => f/5 (equivalent on full frame)

f/2.8 => f/8

f/4.0 => f/11

f/5.0 => f/14

Keep this in mind when shopping for one of these cameras, faster (lower f-stop) optics are better. Also as you increase the zoom, the f-stop will also go up. For example the RX100 mark 4 lens starts at f/1.8 at 24mm, but goes up to f/2.8 by the time you reach 70mm (equivalent). That's almost two full stops, but it's better than the original RX100's lens. That lens went from f/1.8 to f/4.9 at the full 100mm zoom.

Keep the ISO low

Smaller pixels don't handle higher ISO as well. This is because the number of photons recorded by the imaging chip has to be amplified more to get the same sensitivity as chips with larger pixels. This amplification boosts the noise as well as the actual image. Because of this, ISO 1600 might have the same level of noise as ISO 6400 on a full frame camera with larger pixels. We could call this "effective ISO". And if we divide the two, we get a number we could call the ISO multiplier, which would be 4 in this example. As it turns out, with some test shots, this is approximately the ISO multiplier between a RX100 mark 3 and a Sony A7r mark 2. Here is a table of effective ISO's between the two.

ISO 125 => ISO 500 (rough equivalent on full frame)

ISO 200 => ISO 800

ISO 400 => ISO 1600

ISO 800 => ISO 3200

ISO 1600 => ISO 6400

As the ISO's on these little cameras creep up, the effective ISO, or the amount of noise we can expect goes through the roof. So what are the best ways to keep the ISO low? Lower the f-stop (which we've already discussed) or put the camera on a tripod.

Flip out the screen when using tripods

Some of the cameras listed above have flip out screens, where the bottom of the screen goes right to the bottom edge of the camera. Many tripods have rubber pads on the plate where the camera attaches. As you screw the bolt into the tripod mount of the camera, these rubber pads can put a considerable amount of pressure on the bottom edge of the flip out screen. This may bend the hinges of the screen, and the screen will no longer lay flat to the body. The most straightforward solution is to flip out the screen before mounting the camera. That way no pressure will be applied to it. These cameras are small and work great with light travel-tripods and Gorrillapods because the camera weighs almost nothing.

Shoot RAW + jpeg for Black and White

Some pictures are just better in black and white--just ask the street photographers. There can be interesting scenes where the colors in the background are distracting. As a color photo, you can't make it work, but as a black and white, it does. Also there is an artistic mood and feel to black and white. Most cameras will only shoot black and white jpegs, but what if you want all the extra data and editing latitude of a RAW file? The answer is to shoot jpeg + RAW. The camera will show black and white through the EVF and if you play back the images on the LCD screen. But when you copy them off the memory cards, you will also have RAW versions that you can put aside for editing later. In the old days, people would use yellow or red filters for black and white shooting to increase contrast, or emphasize different colors. You can do the same thing with the RAW files.

Conclusion

So now you know everything you need to take brilliant photos with a 1" sensor. When you show your friends the photos, they'll ask "Wow, which camera did you shoot THAT with?" To which you can answer, "Oh, you mean this little thing...?" as you whip out your compact camera.

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