Stop Weining about Hg !!

For anyone collecting/using old cameras you will eventually encounter the battery replacement issue. Starting in 1991/92 there was a restriction on the sale of mercury content in batteries … this lead to the end of all mercury (mercuric-oxide) batteries. Silver-oxide batteries became the best replacement to powering cameras, but this battery used a higher voltage than the 1.35V mercury batteries, which means the older camera meters have to be recalibrated/modified to use them.

WeinCell makes replacements that are of the equivalent voltage … but they ain’t cheap, so here are some alternatives”

The O-ring and Jon Goodman’s 675 adapter are described by Rick Oleson: Cheap Easy Mercury Battery Replacement

same topic by Bruce Varner, here:

… and here is another discussion: Mercury-Oxyde Battery Problem



I don’t often swear, but when I do I mean it … so WTF were these Olympus engineers thinking to use GLUE to attach the front plate on this SP !!!

I have worked on many cameras that are not as finely engineered as this Olympus SP, and they typically had a front lens plate/cover that unscrewed. So I spent the last 30 minutes trying to unscrew the dam thing (though I should have clued in that there is only one slot). Noting the scratch marks from someone who tried to remove it, I continued to do so thinking that it was screwed in crooked and jammed the threading. I gave up and thunk that there is something odd about this.

Some googling later I realized that it was possible that it is just attached with some adhesive. Welllllllll, it’s true. Olympus in their bright minds decided to attach it with shellac !!!

I will get back to this camera after I have calmed down.

Special G … Olympus-35 SP

Hmm, I buy broken cameras … just because they are cheap, and they need help. I find out about what they are after the fact. Sometimes I get surprised, like the Minolta Autocord … and it appears this new camera is also a surprise.

The Olympus 35 SP is a compact fixed lens camera made in the early 70’s … and it appears to be more than just a simple point & shoot film camera … at least from what I have read on the InterWeb.

Ken Rockwell … KR says this camera is the best fixed lens rangefinder camera and the lens is on par with the Summicron … and that’s all I’ve got to say about that.

OK, now that I got him out of the way lets get on with it. I’ve always appreciated Olympus products … I dreamed of owning an OM-4 Ti. The camera looks like your typical 1970’s single lens cameras … except that is labeled with an SP and a G. So you ask, what’s so special about that?

Olympus35sp_DxOThe SP in the model name stands for SPot meter (OK, that’s just my guess) … yes, this camera has spot metering !! and centre weight. The SPn and UC versions are the same camera with just minor changes.

The G is part of the lens labeling, Olympus G.Zuiko 1:1.7 f=42mm … the G is in reference to the number of elements. A,B,C,D,E,F,G = 1,2,3,4,5,6,7. Olympus liked to add this element letter on their lenses, which is a really great way of identifying the variants of the same camera. Hmm, 7 elements in 5 groups … something not expected to find in a camera with a fixed lens (except for the Walz Envoy 35, 7 elements in 3 groups based on image engraved on the top of the camera).

Now, it appears that many others have the same opinion as Ken … this lens (and camera) is really that good … and much cheaper than getting a Leica CL w/ 40mm Summicron. Many people on the Web approve this message.

Cleaning the cat … 500mm reflex

I wanted to try out this oddity of a lens. I shoot a lot of wildlife, so a long focal length lens is handy. Even handier is a physically short and lightweight lens. I snagged this lens for a bit less than normal because there was obvious dust/stuff inside.

I first thought of just removing the front element by unscrewing the ring … but it would not budge. I checked the web, and others show a disassembly … Ok, doesn’t look that hard.

Tools – philiips screwdriver, cleaning stuff, and painters tape

First thing to do is get the tape out, set the lens to infinity focus and place a tape reference on the outside between outer focus ring and body.

TIP: try not to rotate anything during disassembly.

Next you need to take off the PCB board with the contacts. There are two screw holding it on and there is a spring underneath one side.

Next remove the screws from the mounting ring.

Pull off the mounting ring a bid and then maneuver the PCB through the hole to separate them.

The outer body is held on by the four screws.

Note that the PCB and chip are attached to this part, so try not to damage it … and it sits in a slotted area.

At this point you might want to get the tape out again and make more reference marks on any rotatable parts.

In order to remove this rotating focus collar you will need to remove some gears … make a tape reference to its position.

Tip: pull the lens while slowly unscrewing, and as soon as the two release place a tape marker. You’ll thank me when you put it back together.

Two screws hold the gears on.

Try not to lose any parts when you remove it … and also try to keep the lube.

Pull off the column.

Then just unscrew the two parts.

Clean up, and try not to scratch the mirrors.



Those tape marks will come in handy to make sure you correctly get the correct position of everything.

Holy Schmidt-Spiegel Batman … its the Minolta 500mm reflex !!!

The Minolta Maxxum AF 500mm f/8 Relex lens was brought out in 1989, and is a Schmidt-Cassegrain catadioptric lens.

In 1672, Laurent Cassegrain designed a telescope using two mirrors to reflect incoming light to the eyepiece. This design corrected spherical aberrations and also made the telescope shorter. Later on the Catadioptric system was created, and his utilized both refraction and reflection … corrective lenses and mirrors.  In 1930 Bernhard Schmidt redesigned the mirror shape and added an aspherical lens to correct for coma, and astigmatism aberrations. The Schmidt-Cassegrain design is currently one of the most popular telescope design used today … and it also caused many camera lens manufacturers to use that also. Almost everybody made one (well not really), but Minolta was the only one to incorporate it into their Auto Focus system.

The Maxxum 500mm reflex is a stubby barrel of a lens. Due to the way it is designed it can produce donut or crescent shaped bokeh … which probably explains why this lens is not more popular. As I mentioned before, this is an AF lens which can support centre point focus … and since this is a gear driven lens, the body has a direct influence on AF speed. You’ve got one aperture size of f8 so it can cause the AF to hunt … IQ is pretty good on this lens … you just have to know how to work the bokeh … overall I really like this small handful lens.

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