Filter fun

I've been a Canon camera user since I got my first SLR camera as a teenager. Rebellious tennis star Andre Agassi was promoting the new Canon Rebel and that was good enough for me. I progressed thru several Canons, first film then digital, and grew a decent sized lens collection. Since I was a big sports shooter I had my eyes set on the big telephoto lenses and was always glad that Canon produced some of the sharpest telephotos available. But in the past few years, as I've started doing more landscapes, I found Canon's wide angle lenses did not perform as well. Many other Canon shooters had the same feelings and some found a way to mount Nikon's very sharp ultra wide angle lenses on their Canons. Some Canon clan would shun such treachery and liken this to putting a Chevy 350 in a Ford Mustang. But the days of Andre Agassi were long gone and I had no such loyalty to a company that wasn't producing the results I wanted.

So a few years ago when a cheap Nikon lens popped up on Craigslist courtesy of a bad divorce I jumped on the bandwagon. After waiting almost 6 months for the special adapter to be made in England I was off shooting landscapes as sharp as my sports shots. The pictures were awesome. Razor sharp and clean across the whole image. The only drawback to the lens was that it's front element was so big you couldn't mount filters on it. So in tricky light situations like bright skies and dark foregrounds at sunset I had to revert back to my old cruddy Canon lenses. Of course many other photogs complained about this, too, and eventually several filter makers came to the rescue with special holders that mount to the body of the lens. It looked good until I saw the price. All were $300 and up. The holder was almost 3x the cost of the filters.

Being the cheap engineering bastard that I am I looked for a way around this. The holder didn't need to be anything fancy. Just something that could mount around the body of the lens with grooves for sliding in the filters and have a way of keeping out stray light around the edges. Building my own holder would be a good way to satisfy my thriftiness and have fun with the power tools. I sketched up a design and started cutting. I took some old 1/2" plywood that was used for the drawer sides on Abby's dresser and cut a 4" hole in the center, about 1/4" larger than the diameter of the lens.

I cleaned up the board then cut some scrap 3/4" pieces of poplar hardwood, also left over from Abby's furniture, about 1" wide by 6" long. The filter I wanted to mount was a little under 1/8" thick, about the same thickness as the cut of the saw blade. One quick pass on each piece about a 1/4" deep gave a groove for the filter to sit in.

I used a little foam cushioning around the hole to give a snug and soft fit around the lens and help block stray light from reflecting between the filter and lens. I nailed the sides on and a test fit looked good.

I painted the interior flat black

and then cut some old black fabric and stapled it around the top and bottom to block the rest of the stray light.

Of course I would decide to finish something like this just when all the cloudy skies that needed filters would be going away for the season. Luckily there were a few clouds out a couple days ago for Abby and I to go check out the horse ranch near our house at sunset.

It's not the greatest example of what this lens and a 3-stop graduated neutral density filter can do but at least I know it works.

Another popular trend with filters now is the use of extreme neutral density filters to produce long exposure (one minute or longer) images in daylight. I'd always enjoyed doing something similar by moonlight. But being able to take those pictures in the daytime would be beneficial. I already had an old Kodak gel filter that could add 13 stops to my exposure, basically changing my shutter speed from 1/30 of a second to 120 seconds. The filter was too small to fit on the holder I just built but would cover my old Canon lens. Since a filter like this is used too create a motion blurred scene the poor sharpness of the lens would probably add to the effect I wanted. But like my filters for the Nikon lens, I had no way of mounting it to a camera.

Since I had the tools out it was time to make a holder for this filter, too. This filter had to be completely light tight. There were some old used holders on EBay for around $20. But like I said, I'm cheap and like to build things. The basic idea for gel holders is a clamshell design with a circular opening on each half and padding inside to hold the gel softly in place. I took a piece of 1/8 mdf leftover from the drawer bottoms of Abby's armoire and cut an opening about 82mm in diameter. The front filter thread on my Canon lens was 77mm and I had a 77-82mm adapter ring that I didn't need anymore. Fitting this ring to the holder would allow me to screw the holder right onto the lens. With a little sanding I fit this ring snuggly into the opening. On the inside of each board I glued a piece of black fabric and cut a circle to match the opening. When closed the fabric would help hold the gel in place and squeeze together to give a flat enclosure and prevent light leaks.

I put the filter in place and added a little electrical tape to hold everything in place.

Like the filter holder for the Nikon this one really benefits from clouds in the sky. The Saturday after finishing this there were a few midday clouds hanging around while shooting the UCD baseball game for work. I brought the tripod and set up the camera to see what I could get.

Again, not a spectacular shot but the motion in the clouds got me excited about what could be if I find a good location for shooting. Even though I haven't had the chance to put these filters to their full effect I'm still happy that my designs worked and didn't cost anything but time.

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