Saturday, January 23, 2010

In Quest of Warm Hands

Winter in Ottawa is either overcast and relatively warm (right now, it has been overcast for several days, and it's -4°C (25°F)), or it is sunny and cold (-18°C (0°F) or colder). Most winters, we have a period of time where an arctic high pressure comes down, and we get a week of extreme cold, ranging from -30°C (-22°F) at night, to a balmy -20°C (-4°F) during the day.

Trees on Bates Island, Ottawa

Photography under these conditions is extremely challenging, to say the least. When the temperature gets down to -18°C, you have to dress accordingly, and protect any exposed skin to avoid frostbite (and a lot of pain). I have the appropriate clothing – long underwear, ski pants, heavy winter coat, and warm hat. However, covering my hands is another matter. With proper cold-weather mitts or gloves, it's impossible to manipulate the controls of a camera. With lightweight gloves, you can manage a camera, but your hands freeze very quickly, and it is very painful, especially when they thaw out.

So the question is: how do you keep warm hands in very cold weather?

Snow on a Sumac tree

A number of years ago, I bought some “photographer” gloves that had dots of some material that allowed you to grip a camera. They were knit gloves and gave a bit of warmth, but they were not windproof by any means, and were only good at temperatures above about 5°C (about 40°F).

I have also used some cross-country ski gloves that were much warmer, but I still suffered badly when the temperatures were very cold. I could use these gloves down to about -10°C (14°F). Any colder than that, I had to use my cold-weather mitts, and switch to gloves only for short periods.

This year, I have tried out a number of newly designed gloves with modern materials, and some glove liners.

The first set of gloves were purchased from a local “outdoors” store. I bought a pair of Manzella Stretch Fit gloves, rated as “warm, for outdoor aerobic activities”, a pair of Manzella Woodsman gloves rated as “warmest, for outdoor activities in extreme conditions”, as well as some polypropylene glove liners.

A Farm outside Ottawa

The Manzella Stretch Fit gloves are light skin-tight gloves with a very good palm and finger surface for grip. I first used these gloves on a street-photography walk down a downtown Ottawa street, when it was about 3°C (37°F) and windy. I was using my new Canon S90 camera, which is very small and hard to handle with gloves. I found that the glove's grip was good enough for the camera, but some of the controls were difficult as you might expect with a small camera. The gloves were just barely warm enough at this temperature. After about an hour, my hands were cold, but not painfully so. However, these gloves are not windproof, and I think that 3°C is the limit for warmth for my photographic purposes. My walk down the street was not aerobic by any means, and I think the story would be different if I had hiked for a half hour to get there.

I tried the Manzella Woodsman gloves on a much colder day, when it was -16°C (3°F). These gloves were not designed for photography or activities that need a good grip, but I wanted to see how warm they are, and whether I could manipulate my DSLR with them. In the end, the Woodsman gloves are very comfortable, and reasonably warm, but not suited for photography. I tried them with glove liners to see if they would be good in colder temperatures, but I found the fit too tight. I probably should have gotten one size larger to use with liners. Nonetheless, I really like these gloves, and they have replace my cross-country ski gloves for driving, and most winter activities.

A golf course near where I work

After much web searching to find warm photographic gloves, I finally found “AquaTech Sensory Gloves” from Outdoor Photo Gear (www.outdoorphotogear.com). They are waterproof, breathable, and have a silicon dots on the palm and fingers. On top of that, there are neoprene sections on the thumb and index finger with holes that let you stick your thumb and finger out of the glove to control the camera. After some email exchanges with the people at Outdoor Photo Gear (who were very responsive), I decided to buy them and see what they were like.

I tried the AquaTech gloves out on a windy 16°C morning, along with the Manzella Stretch Fit gloves serving as glove liners. I stayed out in the cold and wind for over 30 minutes, and this combination of gloves and liners did very well. It was still difficult to manage the Canon S90, but I expected that. I used my Nikon D200 quite easily, and although my hands got cold at times, I never felt that I wanted to get out of the cold.

The small holes on the index finger and thumb worked quite well. I didn't pull my finger and thumb right through the holes, but I found that I had a better feel of camera controls.

Hoarfrost on trees, taken on an extremely cold day, with freezing cold hands

The Manzella Stretch Fit gloves are a bit bulky as liners. If I had gotten one size larger Aquatech gloves, I think the thickness would be fine. The polypropylene liners that I got from the outdoors store are thinner, and work well inside the AquaTech gloves.

The AquaTech gloves are certainly the best I have tried, and I'm quite happy with them. They are very good for modestly cold weather, and when it gets really cold, they work well with glove liners. I highly recommend them for winter photography.


. . . Rob Williams
http://www.robertwilliamsphotography.ca

Friday, January 1, 2010

Canon S90 Raw format distortion

As I wrote in the last post, Raw format is a very important feature of the S90. One of the first things you will notice is that the S90's raw captures have a significant amount of barrel distortion. Here is the raw capture of a photograph of some bricks, taken at the shortest focal length, 28mm (actually 6mm):


Brick wall, raw format before correction

The amount of distortion declines as the focal length increases, until there is almost no distortion at 105mm (22.5mm actual). The good thing is that it is quite easy to fix, although it is an extra step in post-processing that adds time.

With Photoshop Elements, use the Correct Camera Distortion tool (Filter -> Correct Camera Distortion...).

Here are the settings I use to fix distortion at various focal lengths, using the "correct distortion" slider:

  • 28mm (6mm actual): +25

  • 35mm (7.49mm actual): +14

  • 50mm (10.7mm actual): +7

  • 85mm (18.189 actual): +5

  • 105mm(22.5mm actual): +1
Bear in mind that you may also want to correct for virtical and horozontal perspective as well. Here is the result of the correction, before being cropped:


Brick wall, corrected for distortion, before cropping

The jpeg version of this image is processed inside the camera. The camera corrects distortion, but I have found it is not corrected fully. Here is the camera-processed jpeg, with a slight barrel distortion:


Brick wall, corrected in-camera for jpeg


. . . Rob Williams
http://www.robertwilliamsphotography.ca