A combination of a sunny day, and some free tickets took me to Paradise Wildlife park in Broxborne, Hertfordshire to spend a little time improving my technique using big lenses.
Some while back I purchased a Sigma 170-500mm lens as a bit of an experiment to see whether I’d use a “long” lens, and hence whether it was worth looking at some of the much more expensive Canon offerings.
My initial thoughts about this lens were that I was disappointed with the sharpness of the images, however as I studied the images more closely it became apparent that some images were sharp whilst others weren’t. This meant the problem lay in my technique not the lens.
The 170-500 is a somewhat “low-tech” lens in most respects. It doesn’t have image stabilisation, it doesn’t have HSM focusing and it doesn’t have a f2.8 aperture, however it also doesn’t have a price tag in the thousands!
Recently I’ve been experimenting with shooting at much higher ISO than I would consider normal, i.e. up to 1600 ISO and so for my trip to Paradise Wildlife Park I decided to use these higher ISO settings to ensure I could shoot using the sweet spot in the aperture range and at faster shutter speeds. Although not massive the Sigma is quite a large lens and with such high magnifications (170-500mm on full frame equates to 280-800mm on a crop sensor camera like the 7D) any movement from not holding the camera and lens steady would be exaggerated so I chose to use my monopod to support the weight of the lens and give extra stability.
Although the day was sunny it seemed every animal was determined to hide in the darkest corner of their enclosure, and hence even with 1600 ISO I found many of my shots needed to be taken with the lens wide open to get a sufficiently fast shutter speed. I also switched the camera to Servo focusing since I knew my preferred focusing mode (single shot AF on the back button) wasn’t going to be suitable for moving animals.
To determine the slowest shutter speed to avoid camera with any given lens simply use the focal length as the shutter speed. i.e. with a lens at 200mm a 1/200th second shutter speed would be needed 500mm would require 1/500th second.
However despite these challenges I carried on with my day out and went in search of the big cats!
After a couple of hours I was happy with my shots (being October the light was beginning to fade already) and after reviewing my shots I came away with the following thoughts;
- Shooting at high ISO’s is fine so long as you don’t need to crop too tightly (however with the equivalent of an 800mm lens this is less of an issue)
- Auto focus will work but if you have the time using manual focusing will let you focus exactly where you need to. A long lens shooting wide open will not produce a large depth of field so there’s little room for error. I did feel that this was compounded by the Sigma’s relatively slow focusing.
- The monopod was great and worked better than a tripod had on previous days. Perhaps this was due to the inherent freedom to move a monopod around whereas you would need to have the head loose on a tripod to follow the action, at this movement itself might have caused some instability.
I hope you enjoy these images.
Learn more about Paradise Wildlife Park.