Lens hoods

Frequent readers of my blog will know that I like to tinker with lens hoods. Here is a summary of some of the lens hood solutions I like.

Panasonic Lumix G 20mm f/1.7 pancake

This lens does not come with a hood at all. While a hood is probably not much needed from a stray light perspective, I still like to put a hood on my lenses for protection against objects accidentally touching the front lens element.

My favourite solution is to put a 46mm to 37mm step down ring as hood. This gives some basic protection of the front lens element, while keeping the overall package compact.

I've checked that there is no extra vignetting caused by the step-down ring.

In addition, you'll need a 37mm front lens cap. Both can be gotten from various auction sites for about US$10 in total.


This lens features a traditional focus mechanism, in which the whole lens assembly moves back and forth. Adding extra weight to this assembly is generally not a good idea. However, the step-down ring doesn't add that much weight. Less than a glass filter would, anyway.

Another solution is to get a 46mm metal screw in hood designed for Leica Summicron:

While this hood looks stylish, I think it adds too much bulk. Besides, you might not be able to fit the front lens cap inside it.



Panasonic Leica Lumix DG 45mm f/2.8 1:1 macro

This lens does come with a hood, however, I am sad to say that I find the hood completely hideous:

This hood does look stylish, and reminds me of the older Leica hoods. However, it is much too wide, and could have been used for a wide angle lens. But this lens is a short tele. So the hood does not do a good job of keeping stray light out.

I prefer a hood that is a narrow as possible, while still not inducing any extra vignetting. I found the solution I like by adding three extra elements to the front lens thread: First a 46mm stand off ring (glassless filter), then a 46mm-37mm step-down ring, and finally, a 37mm-28mm step-down ring:

I was almost a bit surprised when I verified that this combination does not add any extra vignetting. But the front lens element of the 45mm macro has a rather narrow diameter, so I suppose it makes sense.

This "hood" does not add any extra diameter to the lens, which is good. In addition, you'll need a 28mm front lens cap. Such a cap is pretty inexpensive.


Olympus M.Zuiko Digital 45mm f/1.8

In a move which has annoyed quite some fans, this lens is not sold with a hood included. There is a hood you can buy from Olympus, which fits in to the bayonet mount. However, it is quite expensive.

I bought a collapsible rubber hood for screwing into the 37mm front threads. It works great:

This rubber hood cost me US$13, including shipment from China.



Panasonic Lumix G 14mm f/2.5 pancake

Just like the 20mm pancake, this lens does not come with a hood. Again, I've used the same solution as with the 20mm pancake lens: A 46mm to 37mm step down ring as hood:

In this case, I had bought a grey ring by a mistake, so I had to paint it black with enamel paint. No big deal.


This lens features internal focusing, so I am not afraid of putting some extra stuff onto the front lens thread.

Panasonic Lumix G 45-200mm f/4-5.6 Mega O.I.S.

This lens does come with a hood, and I think the hood is very well designed:

The only problem I can see, is that it is awkward to insert and remove the front lens cap.

I still changed this hood, since it was a tad bit too long for my camera bag. I got a 52mm screw in metal hood:

This alternative hood is probably not as good for protection, but is is more practical to use, and it's easier to add the front lens cap after use.



Other lenses

The kit zoom lenses generally have well designed hoods, and I see no reason to replace them.

Micro Four Thirds lens lineup

Here is a summary of the lenses currently available, the known upcoming lenses, and some thoughts about future lens needs.

See also my Lens Buyers' Guide for Micro Four Thirds.

Four Thirds system

The Four Thirds systems is a DSLR camera system originally developed by Olympus and Kodak. The first Olympus camera was announced in 2003 (the professional grade Olympus E-1), along with four lenses.

While the major players in the DSLR camera market based their digital cameras on their existing film camera mounts and lenses, Olympus did not have a significant user base at this time, and found it better to design a new system from ground up, based on the requirements of digital photography.

Aspect ratio and sensor size

The name "Four Thirds" cleverly refers to two things at the same time:

• The image aspect ratio. While the aspect ratio of 35mm film cameras is 3:2, the Four Thirds system has a more square aspect ratio of 4:3. There are many reasons for this, e.g., a typical print size is 8:10, with a more similar aspect ratio to 4:3. And professional medium formats are typically closer to square aspects, like 4.5x6, 6x6 and 6x7. However, since the introduction of Four Thirds, formats that are even wider than 3:2 have become popular. TV sets are now typically 16:9. I still think that 4:3 makes sense for photography. A more square format uses the image circle more efficiently, which is an advantage, assuming, of course, that you're not going to crop it down to a more rectangular format.
• The size of the sensor. The sensor has the same size as the imageing area of a 4/3'' diameter legacy cathode ray tube for video cameras. The actual size of the sensor is still significantly smaller than 4/3'', with the diagonal of the imaging area usually being 21.6 mm.

The Four Thirds sensor size is about 30-40% smaller than the APS-C sensors commonly used in other DSLR systems. This has various consequences:

• In theory, a smaller sensor usually means worse high ISO capabilities, and worse dynamic range characteristics, given the same number of pixels, and the same sensor technology.
• The depth of field is larger with a smaller sensor. This means that given the same distance, field of view and aperture, more will be in focus with a smaller sensor. This is both an advantage and a disadvantage. In landscape photography, you will most often want sharpness across the image, and a wide depth of field. On the other hand, in portrait photography, it is often desireable to have a narrow depth of field, to achieve isolation of the subject, and blurring of the background.
• A smaller sensor will limit the useful range of apertures more, due to diffraction, again assuming the same number of pixels. Diffraction will make the image blurry at pixel level when using small apertures. This is not due to bad design, but rather the result of the laws of nature.
• Designing lenses and cameras around smaller sensors is in some ways easier: They can be made more compact.
• A small sensor gives a higher crop factor. The crop factor of the Four Thirds sensor is roughly 2x, meaning that the focal length in mm for a Four Thirds lens must be multiplied with 2 to get the equivalent focal length on a traditional 35mm camera. Hence, a 14mm lens on Four Thirds is a wide angle lens, corresponding to 28mm on a traditional film camera. Some suggest that with this background, systems with a high crop factor are good for people who need long lenses, e.g., for wildlife photography. However, there are lenses to suit virtually all needs in the Four Thirds system.

Lens design

Another important aspect of the Four Thirds mount is the register distance, also called the flange focal distance. The register distance is the distance between the lens mount and the sensor plane. With the sensor size being smaller than for other DSLR systems, the Four Thirds system also has a smaller register distance. This aspect of the camera systems makes designing lenses, especially wide angle lenses, easier.

Olympus lenses are commonly more telecentric than lenses from other systems, especially lenses that were originally designed for film. The telecentric property of a lens means that the light rays coming from the lens hit the sensor at a more normal angle across the field, especially in the corners. This is important for digital photography, since the sensors are sensitive to the angle of the light rays: If the light rays are hitting the sensor at a narrower angle in the corners, a significant portion of the light will be lost in the sensor pixel bins, giving heavy vignetting. More telecentric lenses generally give less vignetting in the corners. However, designing telecentric lenses is more complicated, and some of the size advantage of the smaller sensor is lost with this property of the lenses.

History

The original cameras in the Four Thirds system were not so compact, and, while they were innovative, they were also somewhat strange looking. Later, Olympus launched smaller cameras, with the E-4xx series being the smallest DSLRs on the market at the time of availability. The cameras have also been more traditional looking after the first two-three years. After some years of maturing, the Olympus DSLRs are not very different from the competitors, beyond being somewhat smaller.

Panasonic and Leica have also issued cameras in the Four Thirds system, however with major components Olympus sourced. The Leica branded cameras have largely been similar to Panasonic models, with smaller changes to the design and software. Since this time, both Panasonic and Leica appear to have withdrawn from the Four Thirds system, with Panasonic focusing more on the newer and more compact Micro Four Thirds system, and Leica designing their own high end cameras, e.g., the Leica X1. Leica still appears to have some involvement in the design of lenses for the Micro Four Thirds system, with the Leica branded 45mm f/2.8 macro lens launched in the autumn 2009.

A new standard was announced in 2008, the Micro Four Thirds. This shares the sensor size with Four Thirds, however, leaving no room for a mirror assembly. Panasonic G1, the first camera for this standard, was launched in the autumn 2008. The new system has been very successful in Japan, and Panasonic cameras and lenses have been scarce in Europe and especially the US in 2009, suggesting a high demand.

According to the statistics quoted above, the Olympus E-P1 Micro Four Thirds camera was the most selling Olympus camera model in Japan 2009. This has prompted some concern that Olympus might discontinue the regular Four Thirds line, and focus exclusively on Micro Four Thirds. I think the chances for this are slim at the moment, since Olympus has a large and good back catalogue of Four Thirds lenses. While the E-P1 camera has sold a lot, I am sure that they have sold a lot of Four Thirds lenses as well, not recorded by the statistics.