Monday, September 28, 2009

The Kluge

When I first started this macro project I would have been super proud of this fly image. But I have moved on to the Kluge. Or more accurately the Kluge and a more commercial version now that I've added another flash to my collection.

My 35-70 mm Vivitar mounted directly on the camera give me images with magnifications that varies from a 1/10 (40mm) to a 1/4 (70mm) life size. Add extensions tubes and I can push it up to lifesize or greater imagery. With all the problems.

I don't 'hate' tripods. I just prefer not to be bothered with carrying one around. So if I'm doing 'studio' work in the family room I'll set a tripod up, mount the camera and xy stage on it and shoot away.

Shooting bugs out in the fields and gardens is a different matter. My old manual lens aren't image stabilized. I'm certainly not either as I lean forwards and backwards to bring the bug in and out of focus. And the bug (always) and the flower (with any breeze) are moving.

The one time I tried a tripod in the field or more accurately my back yard I followed advice I'd read in a manual. Find a flower that a bug will love, set up tripod , focus on flower, and wait patiently for bug to strike a pose. Took awhile but once one did, I snapped off five images before it flew away.

Woopee, golly gee. Bound to be keepers since the bug was twice as big as the tiny yellow flower I picked.

I ran in the house to examine my macro masterpieces on the computer. OOPS. Big HEAVY bug on TINY little flower bends flower stem and move everything out of focus. So much for the How-To-Take-Buggy-Pics-In-Your-Backyard manual. Time to think up Plan B.

The problem reduces down to light and speed. With a dash of focus thrown in. With the fly image I had bright sunlight. And a stationery bug for once or I wouldn't have posted the image. Something I didn't have in the roughly 100 other shots I took before I captured this keeper. My success to failure ratio wasn't good.

The obvious solution is a flash to freeze all motion--flower, bug and camera shake. Even better I could have the light I needed. Could shoot with a full stack of tubes for magnification and a tiny aperture for depth of field.

The D60 has a built-in flash with both TTL and manual mode. Unfortunately the lens with extension tubes sticks out so far it blocks the light when I move in close for the shot.

I could have also mounted my best flash on the hot shoe to raise it higher--a dedicated Canon flash unfortunately but the garage sale price was so good I couldn't pass it up. It works fine in manual mode on the hot shoe or with my radio controls and I can dial down the power from full to 1/128 power. Be perfect if I could have tilted the flashead downwards.

So I built the Kluge. Three feet of 1/8 by 1 aluminum strip, a metal switch plate, some hardware and tubing gathering rust in the garage. Add some sawing and drilling and tapping and there you have it. Not exactly something I can fold up and put in a camera bag but the flash mounts beneath the camera so the flash tube and the lens axis are in the same plane.
With it I took the Bee image. And I didn't have to take a hundred plus shots to get it. With good detail too as you can see with the 100% crop of the bee's eye.

Then just as the bee-buzzing--blooms season was ending I found another flash at a garage sale. A Sunpac 322 with a head that can be tilted down. It can't be mounted on the camera; the discharge voltage would fry the electronic, but with my second radio receiver it works fine on top of an old flash mount I had hanging around.

And since the mount folds up to fit in a camera bag, I suspect it will compete with the Kluge come spring when the bee are buzzing blooms again.

Wednesday, September 23, 2009

DIY Closeup Lens

Since the 500 mm lens works well if I don't push it beyond its limitations I'm obviously not going to tear it apart to make an achromatic closeup lens. But I did have another candidate--a zoom lens mounted on a twenty year old video camera with an Vidicon vacuum tube and all the high voltage electronic needed to make the tube work. It came with a separate VCR recorder for the big tapes that fit in a waist harness and--I assume--an equally large and missing battery power pack. Totally non working but since the main attraction of the deal was its big camera bag the camera stuff ended up being stashed away in my basement for some future optics project.

Removing The three tiny screws at the front of the lens didn't loosen anything. (Brought to mind some advice I received as a cub designer/draftsman-"If you goof up put a screw in the goof-up holes to fool them all not in the know.") Since I couldn't locate any other screws and don't own a lens retaining ring spanner out came the hacksaw.

Unfortunately I made a bad guess about the length of the lens assembly. I ended up sawing into what turned out to be an air spaced achromatic doublet. Fortunately I noticed the hacksaw chips between the two lens before I sawed the inner holder in half. After I pulled apart the pieces--they were held together by a press fit using paper shims--I ended with a closeup lens that looked terrible but still worked. Since the hacksaw chips were at or near the principle plane of the doublet they cut the lens transmission by a percent or two but didn't show up in the image.

A powerful closeup lens as it turned out with a focal length of 2.5 inches or 16 diopters. A lens that pushes this method of macro photography to its limits. But once I bought a 52-52mm coupling ring out of Hong Kong it turned my 18-55 mm kit lens into a macro lens. Of sorts. At the 18 mm end I'm in pincushion distortion and vignette heaven.

At the more reasonable 55mm end--judge for yourself. While the closeups aren't as sharp as those from the vivitar macro lens and extension tubes, the closeup lens takes up very little room in my camera bag and is far easier to use. There is something to say for auto focusing, metering and vibration reduction in macro photography.

18-55mm kit lens at 55 mm with 16 diaopter close up lens

without closeup lens

Saturday, September 12, 2009

As I mentioned in an earlier post CPM has moved. On the last weekend in the old building they held a garage sale to get rid of what they didn't want to cart away. Among the goodies was an ancient 500 mm Cambron lens that I remembered seeing for sale at an earlier fundraiser.

The Cambron name is not synonymous with quality, but the bigger problem was the oddball bayonet mount that fitted some equally oddball camera of the 1970's. (a Kiev perhaps) So I moved on to buy other things--lightstands, a photoshop book and a Nikon enlarger lens that may make an excellent UV lens if it turns out not to have a coating that blocks UV.

After I'd gone home I had an idea. As a lens the Cambron may have been useless but if I removed the front lens element it might work as an achromatic close up lens. This idea became even more appealing when, after some Internet research ,I discovered the lens was actually a relabeled Tamron--a lens maker noted for its excellent optics.

So I went back over to CPM on Saturday, saw that the lens was sitting where I left it, and came home with my very inexpensive prize. Turns out I was the only customer that showed up that morning and it was, 'you want it--name a price" day.

Later when I was trying to decide if I should borrow or buy a spanner wrench to remove the lens retaining ring or do a cheapie and take a hacksaw to the barrel, I happened to give the oddball bayonet mount a good twist. To my great surprise it loosened slightly and then unscrewed off. I had bought a T-mount lens!

Tamron was and still is a manufacture of after-market lenses. They had invented the T mount forty odd years ago. No matter what brand of camera a prospective customer owned all the salesman in the camera store had to do was to screw on the proper mount to make what was then a $250-300 sale. And all I had to do was get on ebay, buy a Nikon mount, and up my total investment to $15. Love those garage sale lenses.

Warning--at first I thought it was a M42 lens and almost ordered that adapter. The T mount has the same diameter (42 mm) but has a .75 mm thread pitch rather than M42's 1mm pitch.

So what can this lens do?

The duck picture was taken handheld at a Madison conservation park. I hadn't planned to do my first tests that way and had brought along a tripod. But when I set it up I discovered I'd left the mounting screw in my homemade close up kludge (staring in a future post). Using two rules of photographic thumb, when hand held the minimum shutter speed is equal to your focal length (750 mm equiv on my D60) and the sunny 16 rule (iso 800 to go with the lens's widest f#) it was shot at 1/1000sec at ISO 800 and f8.0.

An ok image once it is reduced for posting it is softer than I hoped when it it viewed full size.

The image quality does improve with a smaller f#. The hand held shot of the swing set was taken from my computer room window across the greenway and a 100 yards away. The noise is higher at 1600 ISO but the nuts holding the swings to the top cross bar must be no more than 1/2 inch in diameter. For a comparison the second image was taken with my 35mm "normal" lens.

Now for a few nature shots. I drove to Fish Camp Park where the Yahara river emptied into Lake Kegonsa--a spot where where swans gather. No swans when I arrived. Then as I stepped out of the car to test the lens on the local ducks, I looked up to see a flock of Mute Swans fly in. Twenty seconds of great images with the camera still locked in the trunk--if only I hadn't stopped for a muffin and coffee at PDG.

Oh well. With luck a power boat would come down the river and I could photograph them taking off. Which didn't happen. By the time the only boat I saw came by the swans had swam up river and around a bend. But I did take my share of feeding swan images. This one was taken from about 100 yards at iso 100, f16 and 125 sec using a tripod.

The other two images are of a pair that were hiding in the reeds across the river. After they decided to visit my side of the river I shot them from about 25 yards using the same settings. The image with the flapping winds is uncropped. The one of the head was cropped to remove a sidewalk in the background.


Sunday, September 6, 2009

As promised--continued

A short one. Due to some accidental keystrokes I published my last post on lens resolution while I was spell checking and otherwise editing it. Since I was still setting up my new laptop--I went with the accident and moved on to other tasks.

Eight X magnification--alas, twas but empty magnification. That means everything was bigger but there was no new detail. Even at 5X magnification I was pushing the ability of the 35mm Minolta lens to resolve detail. The finest 'hairs' on the moth's antenna were 5 pixels wide. This calculated out to be 7 microns wide or about 1/8 the diameter of the average human hair.

And if any of my hundreds of readers (humor, humor) ever want to do this at home the procedure is simple.

Use your version of my trusty machinist rule to see how big the spot you are imaging is. Convert to microns (1/1000 of a millimeter) if your part of the world never got the metric urge. Divide that number by the number of pixels in your sensor to give the micron per pixel number--1.4 in this image.

Then count the number of pixels in the tiny stuff to learn--
a--how big the fine stuff really is.
b--where your lens's resolution craps out.

And how do I know I ran up against case b? Looked at the slide with my microscope.

In an ideal world I'd now upload the microscope image. But the box of slides is buried--I suspect--under the mess of toys, books and other debris in Charlotte's bedroom/toyroom/storeroom. Time for a cleanup. But not today. The weather is too nice this weekend to waste on a cleanup.

So this post maybe continued again