In the Field

About that ISO... Khutzeymateen Inlet (Great Bear Rainforest), BC. May 29, 2009.

It's always gratifying to photograph a wild animal that is so relaxed in your presence that it approaches you and then simply lays down to rest. This female grizzly was probably still uttering many sighs of relief when I shot this image- just the day before she weaned her two-year cub (aka "gave him the boot!") and she could finally just RELAX!

I've included this shot to make a few points about shooting high ISO images. This image was shot under very low light (heavy overcast skies with rain) and I was hand-holding a moderately long and heavy lens. To capture the image using the shutter speed and aperture I wanted required that I crank the ISO up to 3200. The image you see has no noise reduction performed on it (beyond the minimal "default" noise reduction applied during raw conversion).

Today's current batch of mid- to high-end dSLR's can perform amazingly well at high ISO settings, but they still have their limitations...

High ISO's and Digital Noise: Most shooters know that there is a relationship between ISO and the amount of digital noise in an image - the higher the ISO the more noise the image has. Cameras with lower photo-site densities on their image sensors (normally cameras with larger image sensors - those "full-frame" cameras) normally have lower noise at higher ISO settings than those with higher photo-site densities. Some of these cameras still exhibit acceptably low noise at ISO settings at at up to 5,000 ISO or higher (tho' it must be acknowledged that what's deemed "acceptable" in image noise varies dramatically between photographers). But...even with low noise, there's at least one other factor that will often stop you from cranking up that ISO...

High ISO's and Dynamic Range: Virtually all of today's digital cameras have their widest dynamic range (the brightness range of the light that the digital sensor can record) at their base ISO (which is normally their lowest ISO that is numerically recorded). The minute you start cranking the ISO up, the dynamic range begins to drop. Initially all cameras "resist" the tendency to lose dynamic range with ISO increase (some lose little to ISO 200, others to ISO 400, and the top high ISO cameras lose very little dynamic range up to ISO 800). But, eventually, all cameras lose one stop of dynamic range for every doubling of the ISO value (so, they eventually lose a "stop-for-a-stop"). Which means that when you start playing with high ISO's you can more easily lose shadow detail, blow the highlights, or both. So...forget about capturing all the detail in high contrast scenes at ISO 3200! BUT...if the scene is dominated by mid-tones (like this relaxed bear image), you can push ISO pretty darned high and not worry about losing highlight or shadow detail...

There are a few other things to keep in mind with high ISO image capture (and processing). For some reason, many cameras seem to produce wonky colour balances at high ISO. So if you shoot RAW images and normally leave your camera set to Auto WB (white balance), prepare to tweak the WB during processing. And, be careful when you're culling your images - many raw converters or image workflow programs (think Apple's Aperture or Adobe Lightroom or Bridge) use the "built-in" JPEG preview of the RAW image for image display and they can look absolutely gawd-awful (and it's really easy to think the RAW image is just as bad and thus you're tempted to throw it out!). The same can be true of your LCD monitor on your camera - often high ISO images look dreadful on the LCD and not worth keeping. Resist the urge to chuck them out! And, also be aware that image use (size, media) has an affect on image noise - noise always looks the worst when you view a full resolution image at 100% magnification. Simply reducing the resolution of an image (for instance, for display on a website) reduces the visible noise of an image significantly. And, many images that look noisy on a computer screen look much less noisy when printed.

If you're interested in how YOUR camera compares to others on the market in terms of high ISO performance, check out dxomark.com - they have a standardized means of testing image noise in cameras. Note that they value they report for each camera may or may not correlate with what you think is the "highest" ISO your camera can be used at. But the value they report serves a useful purpose in comparing cameras.

This image was captured during my annual "Grizzlies of the Khutzeymateen" Instructional Photo Tour in the spring of 2009. If you're interested in joining me on one of my photo tours into the Great Bear Rainforest, check out the details on my "Seminars and Workshops" page. My Instructional Photo Tours into the Great Bear Rainforest are run in conjunction with Ocean Light II Adventures - they offer a number of amazing adventure tours (including top-notch bear-viewing tours as well as tours of exploration of the Queen Charlotte Islands) and I highly recommend them!

Behind the Camera

About that ISO... Khutzeymateen Inlet (Great Bear Rainforest), BC. May 29, 2009.

Digital Capture; Compressed RAW (NEF) 14-bit format; ISO 3200.

Nikon D3 with Nikkor 200-400 mm f/4G ED-IF AF-S VR lens @ 380 mm - handheld. VR on and in "Normal" mode.

1/250s @ f5.6; no compensation from matrix-metered exposure setting of camera.

At the Computer

About that ISO... Khutzeymateen Inlet (Great Bear Rainforest), BC. May 29, 2009.

RAW Conversion to 16-bit TIFF, including first-pass/capture sharpening using Phase One's Capture One Pro 4.8. Two RAW conversions at different exposure settings. Exposure settings of -0.5 stops (for background and foreground) through to 0 stops (for bear).

Further digital corrections on 16-bit TIFF file using Adobe's Photoshop CS4. Photoshop adjustments included compositing and masking of 2 exposure versions, selective colour saturation and desaturation and selective sharpening for web output. No noise reduction on this image (except the default settings during RAW conversion with Phase One's Capture One Pro.

Conservation

About that ISO... Khutzeymateen Inlet (Great Bear Rainforest), BC. May 29, 2009.

Ten percent of the revenue generated by this image will be donated to Pacific Wild*

Species Status in Canada**: Special Concern (May 2002).

While Grizzly Bears (Ursus arctos) are not technically listed as "Endangered" in Canada, they have been extirpated from most of their historical range. Grizzly Bears are far more sensitive to intrusion/disturbance in their habitat than are Black Bears and are being increasingly forced into marginal habitat by human encroachment. The Great Bear Rainforest along the central and northern coast of British Columbia is one of the last strongholds of the Grizzly Bear in Canada, and even this population is coming under increasing pressure.

*Pacific Wild is a non-profit conservation organization that is committed to:

1. Defending wildlife and their habitat on CanadaÕs Pacific coast by developing and implementing solution-based conservation strategies. Pacific Wild supports innovative research, public education, community outreach and awareness to achieve the goal of lasting environmental protection in the lands and waters of the Great Bear Rainforest.

2. Working with a diverse array of communities, First Nations, groups and individuals to ensure that biodiversity protection is at the forefront of land and marine use decisions.

3. Mobilizing a concerned global citizenry to achieve large-scale wildlife protection.

Natural Art Images supports the efforts of Pacific Wild and encourages you to do the same.

**as determined by COSEWIC: The Committee on the Status of Endangered Wildlife in Canada