My trip around the world couch surfing with Pentaxians has taken me to rural Virginia. Vincent Waldron is a family doctor in a tiny town near the Blue Ridge Mountains who amongst other things takes wonderfully sensitive shots of his family and the district. The landscapes are often done with pixel shift, which is why I was keen to talk with him.
As someone else once noted of Vincent's pictures: "God created sunrises and sunsets, but most people go thru the day without paying attention, as if all is taken for granted. Only some people make it a habit of stopping to observe and to capture the beauty of the fleeting phenomena."
In turn, Vincent has said, "For me, the photograph is the goal, but the real pleasure is in the journey. Being outside early in the morning, smelling the freshly mown hay, or hearing the birds beginning to wake up, is enough for me, even if the photos don't turn out."
His Flickr is definitely worth checking out:
Vincent1825 | Flickr
Me: Thanks for hosting me last night, Vincent. I can't wait to drive into the Appalachians later today. I did take a swig of the stuff in the little keg in the hallway, and I must say, I thought your local moonshine would taste better!
Vincent: Uh ... that's not whisky, Ian, that's window cleaner.
Me: Apology accepted! Okay, we should start with some humour, you're gonna love this ... 'Who is the coolest doctor in the hospital?'
Vincent: If we must. I don't know, 'who is the coolest doctor in the hospital?'
Me: 'The hip consultant.'
Outwardly, Vincent didn't seem to react, but a medical professional can obviously exert great control over their body, anyone else would've been doubled up in laughter, so I followed it up:
Me: 'My favourite game to play in a hospital is hide and seek. But they keep finding me in the ICU.'
(After a pause) Vincent: I think I feel my pager going off. I might be needed at the clinic ...
Me: Okay, okay, let's get into it about Pentax pixel shift. The Bayer array used with the sensor in nearly every digital camera sees the world as just three colours - green, red and blue - and the camera has to make a guess as to what the true colour of each pixel in the scene is. In Pentax pixel shift, the camera's sensor moves by one pixel for each of four exposures, and the data is combined to get a more accurate estimate. Since noise is random, it's unlikely to be repeated in the same pixel with each shot, too, and more likely to be averaged out. Are these advantages you see over a standard picture, Vincent?
Vincent: Yes, Ian, I find that pixel shift adds some color depth, improves shadow noise, and allows for more sharpening before artifacts start to show up.
Me: Since four pictures are being taken and merged, won't movement between the frames cancel some of the advantages?
Vincent: So, the key to pixel shift is having a minimal movement - both subject and camera. I know some people have claimed to have good results with hand held pixel shift, but I am not convinced. A steady tripod and electronic shutter really can help improve results. If you have a scene that has a lot of movement, you won't have good results - going out in a typhoon, even with a steady tripod won't give good results because the wind will keep the frames from matching up.
Me: Right. There's a setting in the camera to mitigate that?
Vincent: Motion correction is a feature that is designed to fix movement in the scene. Basically it masks in the first image shot for any areas where the camera detects motion. But the first caveat is that any scene with lots of motion will require masking of the whole image and you are better off shooting a single image. The second is that hand held simply won't work. Pixel shift requires a pixel level adjustment and that isn't possible hand held.
Me: Understood. Now, not all software understands the four images inside the Pentax RAW file, right?
Vincent: There are two programs that will process RAW pixel shift files. Those programs are Raw Therapee and Pentax's DCU. Other programs may be able to process RAW pixel shift images, but they will produce artifacts anywhere where there is movement in the scene. Pentax uses the first image, but Raw Therapee will allow you to choose any of the four.
Me: You get beautiful images with big dynamic range and crispness across the frame like the shot people will see below ... what are your typical settings?
Vincent: My standard shooting procedure is to shoot on a tripod and use a remote to trigger the shot. Settings are f11 and ISO 100 on full frame and f8 and iso 100 on APS-C. I use Raw Therapee to generate a 16 bit Tiff file that I edit in Lightroom.
I thanked Vincent for his hospitality and also took another swig from the window cleaner container on the way out ... in some bars I've been served worse.
To finish with, there's the story of the older woman who goes to see her GP.
"Doc," she says, "I have a little problem. I hate to bring it up, but I thought it might be an indication that there is something wrong with me. I'm constantly passing gas -- it doesn't smell and is completely silent, but I thought maybe I should get it checked out."
Her doctor examined her carefully, wrote a prescription and asked her to return in a week.
When she came back, he asked her how she was doing.
"Terrible! I pass gas just as much as ever and they are still silent, but now they smell just awful!"
"Good," he said, in response. "We're getting your sinuses cleared up, now it's time to work on your hearing ..."
Find the rest of the series here: Clackers' Beginners Tips (Collected) - PentaxForums.com
 Sunrise and Puddle by Vincent1825, on Flickr
|
