Steve Cole Photography

I recently ended a long quest to pick up my “wildlife”zoom lens. As a brand, Pentax has not kept up with developing long length zooms (or primes for that matter) for use in wildlife photography. The Pentax branded lenses out there hail from the end of the days of film and the FA series of lenses. For modern times, options are really limited to a few offerings made by third party lens developer Sigma.

Sigma has been producing their 500mm (750mm equivalent with the Pentax 1.5x crop) beasts for a while and their offerings boil down to the 150-500 or the 50-500, which is affectionately known as the “Bigma.” Based on my research, the 50-500 was held in high regard for both it’s image quality and value. The current version of this lens retails for about $1600 in a Pentax mount and uses a HSM motor for focusing. Pentax’s own lenses with HSM motors have been suspect so I wanted to avoid this and target a used copy of the previous version of this lens (the 50-500mm F4-6.3 APO DG).

I thought I had scored a deal on one using eBay but the seller had mistakenly listed their Nikon mount lens as a Pentax mount.There’s nothing worse than opening a box and realizing the lens you see won’t fit your camera! Anyways, fast forward a few weeks and I found an individual selling their one year old Bigma for $825 on a Pentax forum. For an additional $50, the seller threw in a UV and Polarizer filter so I jumped on it.

I’m not really a wildlife photographer but occasionally find myself in those kind of situations. What’s more, there have been a few times when I knew that the extra length beyond my normal 300mm tele would have yielded a much stronger composition and image. I’ve wanted to take this lens out for a spin but haven’t had the time until a few days ago. I tried stopping by the Mosquito Lake Rd bridge over the North Fork Nooksack River but there wasn’t a single Bald Eagle to be found. If I was going to use this lens, it would have to be landscapes.

Before that, however, I stopped briefly at Nooksack Falls. I hoped to get a “wintertime” counterpart to my ladder-aided shot of Nooksack Falls from last summer. To my disappointment, much of the snow that fell a couple weeks ago has melted away..

After that, I continued up the Mount Baker Highway to hit the slopes at the Mount Baker Ski Area. The skies were partly sunny with clouds drifting in and around the neighboring peaks. Perfect for dramatic photos! I decided to only use the Bigma so all of these photos were taken with the 50-500 and a UV filter:

I’m really happy that I picked it up. It is a HEAVY lens and weighs in at over 4 pounds. I won’t be taking this out on a hike very much! Another caveat is its construction so you should be mindful of its use during extreme conditions. Living in the wet confines of the Pacific Northwest, I’m very accustomed to being out in rain and snow. My camera body has weather seals but my lenses do not. I have not found this to be an issue overall but the Bigma is put together slightly different.

Six screws retain the front most element of the lens to the rest of the extending body of the lens. Given our proclivity to rain, I’m real concerned about moisture penetrating this seal. Thankfully, I have found an inexpensive solution but I’ll blog about that after I have had some time with it in actual rainy conditions. My Manfrotto ballhead can support the weight of the lens and camera but it is sensitive to vibrations. Using the camera’s timer or better yet a remote control helps mitigate for this.

The extra 200mm at the extreme end of the range does make a difference. There’s been one composition out along the Shuksan Arm that I’ve wanted to shoot but have been unable to since it won’t fill the frame at 300mm. It now does and hopefully I’ll be able to shoot it before the end of ski season next month. Focusing is fairly fast and snappy but it has hunted for focus in low light and low contrast conditions. I’ve been able to work around this by either selecting a higher contrast focus point or by pointing the lens at a higher contrast portion of the scene and then recomposing for my original scene.

The Canon / Nikon versions of this lens have a few switches near the mount which control zoom creep and manual / auto focus. The Pentax version only has the zoom lock switch and I gave myself a heart attack as I unintentionally discovered that manual / auto focus is controlled by a push/pull of the focusing ring. I thought I had broken the lens!

My last comment is about the lens hood, which requires some consideration. The horizontal petals almost half the depth of the vertical petals, presumably to avoid appearing in the frame at 50mm. My very first attempt using this lens was at a local estuary wetland during a windy rain. Although I was perpendicular to the wind, it was blowing water droplets in and onto the front of the lens. This is something I have not encountered with my Pentax DA55-300 which uses a lens hood with a uniform, deep length. This isn’t calamity by any stretch but I think folks should be aware of such things. Sometimes the photos we take can’t be duplicated so I would hate to loose a photo because I didn’t check for water droplets!

[UPDATE] I haven’t had many opportunities to use this lens until recently when I visited Boundary Bay in British Columbia to photograph the Snowy Owls. You can see those photos in my blog post here.