Weekly Photo

As additional motivation to play with the camera, I’ve set myself the task of taking at least one interesting photo a week. Then I will post that photo on a Piquero web-page. This week’s photo is here.

The originals are JPG files but very large (1 to 2 Meg). So I’ve resized the photos to about 25% of the original. I also cropped the image to take out excess border data. That brings the files down to 54K.

I’m also going to add a link to the page over on the left hand side of the blog.

Another Field Trip

Nice day but windy today. Decided to take another field trip, since I was on my own for lunch anyway. Drove down to Lady Bird Lake, in Austin, to check out the ducks at Lou Neff Point.

Had a couple of features I wanted to try. (1) Some of the scene settings. And (2) Exposure bracketing.

I like the knarly trees that haven’t begun to bud yet. Just a tangle of bare branches. The park has a number of them. Took the monopod along and snapped a few trees. Tried the “Landscape” scene selection. The results did seem a bit richer in color.

The information stored with the image (back at home on the computer) indicates what settings were used. I only took minor notes, and then verified the actual settings back home.

The water and the ducks presented a different problem. Had a lot of reflection off the water, from the overhead sun. I tried different shots with the Exposure Bracket setting. The +0.3 EV (slightly over exposed) produced a better photo. This is probably the result of the reflection making the scene look brighter to the photometery system.

I can also bracket +/-0.7 EV. But the higher bracket gave a more washed out image.

Looking over the lake to downtown Austin let me try out “Landscape” mode. The pictures are darker than I want. I tried out White Balance (WB) bracketing. It didn’t seem to make much of a difference. I tried WB on a tree full of berries. This produced some noticeable differences.

One final experiment. Most of the trees are still bare branches. There is one, however, that is covered with orange/red berries. Very colorful. I took some photos with the “Macro” scene setting. Gave me a very nice blurred back ground, i.e. short depth of field, so a single cluster of berries could be isolated.

Back to the drawing board

Record high temperatures in Texas yesterday. Clear sky and sunny, so a good day to play in the back yard with the camera. I set up the experiment to test depth of field.

The results weren’t as straight forward as I’d hoped. I can detect the blurring but spacing the coffee cups along the tape measure didn’t give me the contrast I wanted. Plus, at greater distances I couldn’t be sure if it was blur or lack of resolution. I’d set the camera to Small quality, and had to look at 100% pixels on the computer.

I did, however, find a site DOFMaster that has a calculator. The numbers roughly correspond to my observations.

Particularly for the 80mm setting. It was clear that the near field was short, less than a foot in front of the coffee cup. The 35mm setting was harder, because you get about 1.5 to 2 feet in front and back. That was about the height of the total frame, so I couldn’t detect a lot of bluring.

The Wikipedia entry for Depth of Field has a lot of formulas. But it has a few example photos. It looks like F-stop is the critical parameter, along with subject distance.

I need to construct a better subject setting.

View Finder

I know that conventional lenses on a digital camera take a hit, about a 1.5 crop factor. In practical terms that means my viewing area is less wide. Reviewing the pictures I took at EPCOT, last week, it was obvious.

I decided to run a practical experiment this afternoon (Sunday). I wanted to see two things. (1) How wide is my vision? and (2) How much more than the viewfinder focus box is included in the picture?

My home faces West, so the setting sun hits my front door in the late afternoon. The sun would be at my back and provide great lighting. The house has a low wall, a bit over 5 foot high, in front of the house.

I took some oversized yardsticks (4 foot) and laid them on the wall. Then I took index cards, drew a line down the center of the card, and then folded the card (line inside). I positioned a card every 1 foot, using the yard stick to hold down the card, i.e. slipping the bent half under the yardstick.

I got my 50 foot tape out and fixed one end at the wall. Then I stretched the tape out toward the sidewalk, essentially at a right angle to the wall.

I got some quad ruled paper and recreated the viewfinder focus box.

With the camera mounted on the monopod, I’d take the camera out to a 5 foot mark and look through the lens zooming between 35mm and 80mm. At the two extremes I would note the index cards visible relative to some of the focus marks, and then snap a picture. (Here's a cropped example )

I’d record on my grid paper how wide I could see in the focus box, not the total viewfinder.

Then I would repeat the process at the next 5 foot interval, i.e. 5, 10, 15, 20, and 30 foot from the wall. The monopod was always at the same height. So, even though my lawn slopes down a bit toward the curb, all the pictures were roughly of the same scene and the same relative center. The index cards (i.e. the horizontal) were always visible.

Took the pictures with medium resolution. Then I took a few with small resolution, and a couple in large format. “Size” is really a designation for pixels not image dimensions.

After cleaning up my props, I downloaded the test pictures to my computer. Definitely cheaper than 1-hour photo processing. Then it is mostly a question of trigonometry.

The calculator function in Windows is a bit limited. It will do square roots but not sine or cosine. Not to worry, I have my CRC Math tables and a slide-rule for backup. (The slide-rule doesn’t have a sine scale but does have a T (tangent) scale.)

It looks like the 35mm opens up about 36.52 degrees. That works out to 6.6 ft from 10 feet out, between the focus box brackets. The resulting image adds about 1.5 feet outside the focus box, on both sides. (Distance from target x .33 = one half of the focus box view.)

The 80mm setting is a little less than half that. At 20 feet, 6.32 feet are in the focus brackets, about 18 degrees of view. The image adds about a foot to the edges, on both sides.. (Distance from target x .158 = one half the focus box view.)

The images are identical for S, M, L images. So the number of pixels (resolution) changes but not the image width.

I think my next excursion into physics will be to lay out the tape and place my markers every foot straight out, stretching in front of me like a path. Then if I focus on one marker, I should see the depth of field impact to other markers.

Field Trip

The field trip was a success. I learned a lot about the camera and the monopod. In no particular order of priority:

• The quick release worked about the way I’d hoped. I need to occasionally tighten the mounting plate on the camera, but it was easy to snap in and snap off.
• Tilt head can be a mystery for the TSA. The guy in Austin couldn’t recognize it, but he may have been new. Tampa didn’t have a problem with it.
• Had some improvement in the “shake” indicator. Found it was best when I was sitting on a bench. But I did take a few low light shots, standing up, that came out well.
• Overall weights weren’t a problem. I carried the monopod, head, camera, and extra lens in a backpack. They weren’t a burden. Didn’t always fit in the provided self/storage on a ride, but that’s a function of monopod length.
• Monopod just fits into the backpack on the diagonal. Most of the time I let it poke out between the two zippers. But, I could, in a pinch, wrap a plastic bag over the whole works and close it in the knapsack.
• I might want to get a longer hand-strap on the monopod. It was just as easy, however, to carry it in the middle, like an umbrella. I usually took the camera off the mount when I was moving to another location. This afternoon (Sunday) I was running another experiment and left the camera mounted as I moved back and forth to the clipboard, carrying the monopod.
• A pratical observation. Start extending the legs from the bottom, if you’re planning the full length. You might not be able to reach the lower leg if you have you hand in the wrist strap.

Bought The Monopod

Ran some errands today, kind of all over the Round Rock and Austin area. In the process, I picked up the monopod. I had planned on getting it Wednesday, on my way back from SCORE. But the camera store doesn’t stock them.

Instead I got out the yellow pages and checked with other camera stores. Found one that had them in stock.

What I picked up was a Bogen (Manfrotto) 676B Light Monopod.. About 19 inches collapsed. Looks like it’s going to do the job. It will certainly pack in the duffle-bag. That was one requirement.

I also picked up a Bogen 3229 swivle head with quick release. It has a mount and a release mechanism. The release part has an extra pin for locking.

I wasn’t paying attention to where the lens was pointing relative to mount mechanism. When I unscrewed the lock for tilting, the camera move forward and pointed down. Fixed the orientation and now can swing from horizontal to vertical.

And the main feature, being able to move from monopod to hand-held was accomplished. Perhaps not as fluid as I want for November. But that will come with practice.

A Third Leg

Between primaries and planning a trip to Florida, haven’t been very active with this blog. Last big step was solving the air travel.

I’m back to focusing on the digital camera and gear. I’ve starting looking at monopods rather than tripods for the Antarctic trip. Weight and bulkiness seems to me the key factors. The use of a monopod is usually good for sporting and nature events where the photographers move frequently. That sums up my impression of Antarctica.

Assuming the land visits will be like the Galapagos. A fair amount of hiking, even along the beaches to see the wildlife. I think a tripod would be too bulky. A monopod will give me some stability.

Obviously, as the weight of the monopod goes up, so too the weight it can support. The smaller compact units, while reasonably priced, only support a 10-11 pound payload. If I had a huge telephoto lens, this would be a limitation.

I decided to weigh the Alpha unit with the 30-80 mm lens, the most likely configuration. Came out 1 lb 14+ oz. My film unit, with an 80-200 mm lens was 1 lb 15oz. The lenses themselves are spec’d at 6 3/16 oz and 10 9/16 oz. So I’m only looking at 2.5 lbs on the payload.

Bogen makes a light monopod. They also have a quick release swivel “head” that looks interesting. It isn’t a ball-mount. Just the ability to tip from horizontal to vertical. But it provides a mount for the camera that can be snapped in or snapped off the monopod. That is intriguing. That would save time if you can go from mounted to handheld without a lot of extra “screwing around.”

The tilt head adds 0.6 lbs. The tilt head has a max capaity of 5.5 lbs. Still more than enough for the 2.5 lbs of payload.

If I pick the equipment up this week, I can take it to Florida for a field test. We are going to visit Epcot. So, that would be my first real use of the camera and monopod.