Everything in this article is also applicable to the previous C-series cameras from Olympus: C-40x0Z, C-30x0, and even C-20x0Z (where the 'x' stands for a digit differentiating between similar models), but not to the more recent ones: C-5060WZ and C-7070WZ.

Why a lens adapter?

The collapsible, motor-driven lens in the '5050 does not have a filter thread. Besides, it is not mechanically secure enough to carry the weight of any auxiliary lens attached to it, even if there were a way to fit one.

The lens adapter (also known affectionally as the "lens tube") can be used for three purposes:

• To protect the lens from mechanical damage, and to avoid the motor struggling when the camera is turned on while a lens cap is in place;
• To provide a mounting thread for filters (with the UV or daylight filter protecting the lens front element from dirt, water droplets or mechanical damage);
• To allow for mounting of attachment lenses expanding the available range of focal lengths (view angles).

What you sacrifice using a lens tube is the neat compactness of the camera with it lens retracted: it no longer fits ever-so-snugly under your jacket. The tube adds about 2.5 cm to the camera's depth.

The choice if yours, but it is not irreversible. You may decide on a case-by-case basis whether to equip your camera for a given outing, or not. I have used a lens tube on a C-3000Z at the time it was my main (and only) digital camera. With the '5050, I am a little undecided, but after a few months with this camera I find myself using the adapter most of the time.

Which one?

There are a few lens adapters designed to work with the '5050 (or other Olympus C-series cameras). All of them have a 41 mm rear thread (fitting into the camera body), differing in the front thread size, and, to a lesser degree, in the overall length.

• Olympus sells an adapter designated as CLA-1 since the original C-2020 was introduced back in 1999. It has a front thread of 43 mm, and the length (excluding the thread which goes into the camera body) of 23 mm. (The same adapter together with a 43-55 mm step-up ring is sold as CLA-5.)
• Tiffen offers a current model named OLYC3000AD, also with the front thread of 43 mm, but longer: 26 mm.
• There is also an older adapter by Tiffen, OLYC2000AD, of a conical shape, still available at some outlets, with the front thread of 49 mm, and also 26 mm long.

In addition to the above, Kenko makes two adapters: one being an almost exact copy of the CLA-1, and one with the front thread of 52 mm. I haven't tried either of these two, so all I can offer is a link to the THK, their U.S. distributor. (Some dealers mention other Kenko adapters for the '5050, but the THK site does not list them, and I have not seen even the pictures.)

CKC Power, an outfit specializing in digital camera add-ons, also have a number of adapters fitting the '5050, which you may check for yourself, especially if you need some other filter thread diameters.

In this article I'm focusing on the Olympus and Tiffen models, as being most common and most readily available. As these are the only ones I have used, I will not be able to answer your questions regarding other adapters.

Let us have a look at all three models mounted on a C-5050Z camera, each with a filter attached to the front.

For those who like to know such things: the pictures were taken in my seven-dollar tabletop studio, outdoors, late afternoon, shade, cloudy. Camera used: Olympus E-20, aperture priority with -0.3EV compensation, 1/3 s at F/8, zoom EFL=140 mm, tripod.

Does size matter?

The Olympus adapter is about three millimeters shorter than the Tiffen ones. This is, I believe, for historical reasons: when it was introduced back in the pioneering days of the C-2020Z, Olympus attachments had various rear threads: from 46 to 55 mm. This is why the adapter was made a little shorter than needed for the fully extended lens — the step-up ring necessary to match the tube's 43 mm front thread to that of the auxiliary lens would provide extra spacing.

A side effect of that is that you also need that spacing to use just a filter, or a lens cap, on the CLA-1. If you try to mount a filter directly on the tube, the front of the lens will jam into it when fully extended.

One exception is a polarizing filter. These usually have two rings: one with the filter mount, and another one, holding the filter glass on top of that, to allow rotation. This adds some extra space, just enough to accommodate the lens. Therefore usually you will be able to use a 43-mm polarizer directly on the CLA-1.

Of course, the CLA-1 could have been just a tad longer, to free us from the step-up ring hassle when filters are used. The designers wanted, however, to keep the spacing between the lens front and the lens attachments as small as possible. This, theoretically at least, assures better optical quality and minimizes the chances of image corner cut-off and/or vignetting.

The Tiffens are long enough to accommodate the lens, and filters can be used on them without any extra spacing. This is an advantage, but what about the vignetting and the optical quality loss?

As a former physicist I don't take anything for granted. From general considerations, the spacing issue will be more critical, if at all, for wide-angle attachments. Therefore I used the new Olympus WCON-07 wide-angle converter mounted on both tubes (CLA-1 and ALYC3000AD) to shoot pictures of a lens resolution target; then I compared both samples under magnification. The moment of truth: I was not able to see any differences in resolution between both tubes, although I expected to see at least some. There was also no vignetting visible with the use of the longer (Tiffen) adapter.

Mind it, this was not a measurement, but a qualitative, although painfully scrutinizing, comparison. Still, if I cannot see a difference in an image magnified on my screen, I will not see it even in a 9x12" print.

Therefore my conclusion here is clear: the size difference between 23 and 26 mm does not matter optically, not in any degree I could notice. You may base your choice between the available lens adapter models on other factors.

The CLA-1 is just a millimeter short of being able to fit the extended lens; the Tiffen tubes are two millimeters longer than necessary. Settling down on one length of 24 mm would make all this discussion irrelevant, and I don't quite understand why both makers didn't do just that.

Choosing the right adapter

Now this seems to be simple. With the optical question answered, and having used both the (new and old) Tiffens and the Olympus model, I prefer the (new) Tiffen OLYC3000AD for a number of reasons:

• The Tiffen allows to use filters without an additional step-up ring. This is not only the matter of convenience, but also of the viewfinder being partially obstructed by the adapter/ring/filter combo. On the Tiffen model the obstruction, visible at the bottom, is very slight, and only at the widest zoom setting. With the CLA-1 you have to use at least the 43-46 mm step-up ring; being wider and bringing the total length to that of Tiffen, the combination obstructs the view significantly more. (This is also why the "old" Tiffen is out of the competition.)

  One reader reported success using a filter straight on the CLA-1, without any rings. Obviously, either this was a polarizer, or some filters may have the glass little bit more to the front, just enough to accommodate the lens.

• The Tiffen has a matte black finish, matching the overall look of the C-5050Z better than the glossy surface of the CLA-1. It also has a nicer (less nerdy) shape. These may be just cosmetic differences, but still. The obtrusive white-painted Tiffen logo can be easily obliterated (or almost so) with some nail polish remover.
• 43-mm filters, usable on the OLYC3000AD, are less expensive than the 46-mm ones fitting the CLA-1 with the 43-46 mm step-up ring. (Theoretically, you could use a 43-43 mm ring before the filter, but the only way to get one seems to be by taking the glass out of a 43 mm filter, a waste).

You can buy the Tiffen tube at a number of U.S. dealers, including my favorite source, B&H Photo. The Filter Connection, a small-town business dealing only in filters and rings, has a well-stocked inventory, and is another checked and proven alternative.

Problems with the built-in flash

What else you may need?

If you are going to use any attachment lenses, you will need the right step-up ring(s). For both new Olympus lenses, WCON-08 and TCON-17, this will be the 43-55 size.

If you plan on using the tube for lens protection (with a 43 mm UV filter, in case of the Tiffen adapter), remember that your lens cap which came with the camera will be now too small (41 mm instead of 43 mm). You need a 43 mm snap-on lens cap.

OK, this is perhaps the longest article on a $15 accessory I have ever seen. Now get out and take some pictures.