zuiko digital super telephoto

300mm x F=2.8 ON TEST


The Zuiko Digital 300mm x f=2.8 is the most expensive in the ZD range of lenses. This SuperTelephoto is hand built to order in Olympus' factory in Japan. It has a formidable reputation and has been amusingly christened as 'Big Tuna' by Olympus fans. It's smaller sibling, the ZD150mm x f=2 is known as 'Baby Tuna'.

The ZD300mm is a typically large telephoto lens, weighing in at 7.2 pounds (3.3kg) with tripod mount, 11.2 " in length X 5.1" diameter with an additional 5" of lens hood. Though it's quite possible to use this lens hand-held, a tri or mono-pod is recommended.

The lens has the equivalent field of view to a 600mm x f=2.8 on a 35mm camera, with the equivalent depth of field to a 600mm x f=5.6 lens on a 35mm camera. Its optical specification is: 13 elements in 11 groups, 3 ED elements, 9 bladed diaphragm and a 'drop-in' rear filter holder (40.5mm). Angle of view is 4.2 degrees with a close focus distance of 2 meters. It is compatible with the EC14 and the EC20 (subject to camera body firmware update).


Scanned image of the ZD300mm x f=2.8

Lens architecture (courtesy of Olympus Imaging, Japan.)


This piece is a joint venture by Ken Rowe, a UK based amateur photographer and myself. Ken recently joined The Olympus Circle and told me he had the 'Big Tuna' for use with his E-1 and was soon to be buying an E-3. It seemed like a great idea to put everything together and produce an article that looks at the way the ZD300mm performs on both the E-1 and E-3. Unknown to me Ken also included some test images using the E-3 with the ZD50-200mm (2.8~3.5) and the EC14 Teleconverter to see how it faired against the hugely expensive ZD300mm.

After a few email exchanges in which we discussed the potential target, I received a CD with Ken's test images. These are jpg's taken directly from the cameras involved without any post processing. All I have done is crop out the main target area and re-sized these for ease of comparison; they have received no other processing.

Regarding the test, Ken says:

"As the objective of the test was to look at the ZD300mm lens results on both a 5MP and 10MP sensored E-System camera, I set the cameras to produce colours and sharpness as close to each other as possible and how I normally have them set for my everyday use.

Both cameras were set to the same in the following attributes: Aperture Priority, ISO = 200, WB = Auto, Metering = ESP, Saturation = 0, Contrast = 0.

The E-3 was set at LSF, Picture Mode = VIVID, Sharpness = +1. The E-1 was set to SHQ, CS2, Sharpness = +2. (I find these settings in each camera produce very similar results in terms of colour rendering and sharpness.

On the E-3 IS was set to OFF, both camneras set to S-AF although the EXIF for the E-1 shots indicates MF and I think this is due to my setting being S-AF+MF."

As the cameras are of entirely different specifications in any case those slight differences do not impinge negatively on the results. Strictly speaking we cannot directly compare the sets of images and the results should not be taken as definitive, more indicative. Nevertheless, it forms a good basis for comparison.


Here is the target set up by Ken. Test exposures were done on an early February day in UK so the ambient light is diffuse resulting from a bright day with hazy sunshine. The tripod was approximately 30 yards from the target and both camera shutters were triggered with a CB1 remote control.

The area edged in red is the cropping target.

E-1 & ZD300mm:

Let's look at the results from the ZD300mm on the 5MP sensored E-1.

Wide open the 300mm produces a slightly soft image.

This improves significantly as the aperture closes 1 stop.

At f=5.6 this is a well rendered and quite sharp image.

There's little difference between f=5.6 and f=8; the sweetspots, no doubt.

Here at f=11 the image is just starting to go backwards being ever so slightly less sharp.

At f=16 you can see diffraction has set in producing an unsharp image.

f=22 brings the worst image in the series, unsharp by some degree.


I've judged these results by looking at the GARAGE DOOR advertisement in the bottom left of the paper. The words above the illustration are: AUTOMATIC ROLL UP and if you compare how easily,or otherwise, you can distinguish this lettering will give you an idea of how good the delivered resolution has been.

It's plain to see the sensor is the bottleneck here with the lens resolution far outstrippimg that of the 5MP sensor. While the images are quite good, even at the sweet spot of f5.6 ~ f8 they are a little 'lacking' in 'bite'. However, when compared to the 10MP sensor on the E-3 these are not too bad at all. Remember that to double the resolution you need to quadruple the pixel count.

E-3 & ZD300mm:

Let's look at the results from the ZD300mm on the 10MP sensored E-3.

Wide open the 300mm again produces a slightly soft image but there is more detail here.

The improvement is quite dramatic as the aperture closes 1 stop.

At f=5.6 this is a very well rendered and quite sharp image.

There's little difference between f=5.6 and f=8; again, the sweetspots, no doubt.

Once again, at f=11 the image is just starting to go lose bite, being ever so slightly less sharp.

At f=16 diffraction has already set in producing a slightly unsharp image.

f=22 brings the worst image in the series, but actually not bad, we can easily read the chosen text.


In the above set it's plain to see the effect of having more pixels has on resolution. These are a lot crisper; have a bit of bite, especially in the sweet-spot apertures. It is possible to distinguish AUTOMATIC ROLL UP in all the images.

The major difference to my eyes are the images from the E-1 NOT in the sweet-spot that are clearly much worse than those from the E-3 in the same range, yet those in the sweet-spot are only marginally worse. In other words the rendered images within the sweet-spot are not that far apart; yes there's a difference but perhaps less than you might imagine. But images not in the sweet-spot are much worse from the E-1 than the E-3; more in line with what you might think.

E-3 + ZD50-200 & EC14 (to give 280mm at F=4.9):

Ken decided to test the ZD300mm x f2.8 against the ZD 50-200mm (f2.8~3.5) + EC14 at its maximum of 200mm making it an(equivalent) ZD280mm x f=4.9, just to see how big the difference is. The images below have been cropped in the same way and re-sized to match the above. There's very little physical difference in the crop size.

At an aperture of f=4.9 this is the combo wide open. Not too bad at all; we can read the chosen text.

Closing the aperture to f=5.6 produces a marginal improvement; the chosen text is easily legible.

At f=8.0 this is a well rendered and quite sharp image considering the combo.

Here you can see diffraction is just starting to show; the image has marginally less bite, but is still acceptable.

At f=16 the image has deteriorated considerably as diffraction is amplified by the EC14.

At f=22 we see the effects of small apertures; this is quite horrible.


In the above series of six images I think the ZD50-200mm in combination with the EC14 Teleconverter does quite a good job bearing in mind the difference in price between the two lenses (lens combinations.) The ZD300mm costs around 4,500 whereas the combination will cost you 1000. Is there 3000 worth of difference - well only you can judge.

Certainly in the first three crops (f=4.9, f=5.6 and f=8) there is little to compalin about; these are better than the ZD300mm on the E-1. Compared to the results from the ZD300mm on the E-3 I think they stand up quite well. OK they are a tad softer with marginally less bite but you can still easily read the selected text without difficulty. Is the combination on the edge of its resolving power? Quite possibly considering the amount of glass the light is coming through (22 elements in 20 groups) there's a lot of potential for a bad surface. But we won't know until the next generation of E-cameras arrives with increased pixel counts.

Again, and just the same as the ZD300mm performance on the E-1 and E-3 diffraction kicks in around f=11 to f=12 but in this case the EC14 magnifies the diffraction effect making it appear much worse in the crops at f=16 and f=22.

Don't forget the defocused areas produced by the ZD50-200's 7 bladed diaphragm plus EC14 will not be as well achieved as the 9 blades of the ZD300mm's diaphragm. Unfortunately we don't have an example to show you.

So what's the difference? Wide open the combination sets off at f=4.9 as opposed to f=2.8 with the ZD300mm. That's very nearly a stop and a third. Therein lies the significant difference, the ZD300mm is innately faster. The apertures level out at f=5.6. Performance from the combination is surprisingly good, way better than I'd anticipated compared to the Big Tuna. But please remember we have only examined the centre of the images, corner resolution may not be as good.


To illustrate how the above images will look after a bit of processing (levels, contrast, colour lift and one pass of unsharp mask) here are three exmples at the sweet-spot of f=5.6.

E-1 with ZD 300mm f=5.6 - has taken the sharpening quite well; overall a good result.

E-3 with ZD300mm f=5.6 - sharpened up well; to my eyes the best of the bunch (to be expected).

E-3 with ZD50-200mm and EC14 f=5.6 - again, very respectable.


There's not a great deal to put between these processed jpg images. With more processing skills they could all improve. If I had to mark them I'd put the E-3 with EC14 and ZD50-200 in third place (because of the slight grey tint to the image), E-1 with ZD300mm second and E-3 with ZD300mm first (as we might expect).

As with all lens tests much depends on the conditions on the day of test and ones own level of applied subjectivity to the results as we all see things differently. And, of course, lens test shots are by their very nature, boring!

Here's an image of Ken's test rig.

Ken's E-3 loaded with the Big Tuna. An impressive sight and judging from Ken's gallery shots capable of great images.


Nothing is more effective than showing the results, even low reesolution web images, so here's a couple from Ken's gallery we thought would show off the ZD300mm's capabilities more than boring test shots. There are more images to look at in Ken's gallery that can be seen: here.

E1 ZD300mm+EC14, A, f4, 1/2500, ISO200.

E1, ZD300mm, A, f4, 1/1600, ISO200.


We don't think there are any conclusions to draw from the exercise. I first suggested it to Ken to see where diffraction kicked in with this lens on his E-3. It's pretty obvious that Ken was interested in more!

The more you pay for a lens the more you get; not necessarily in additional dollops of resolution but certainly in the critical area of lens speed allowing the photographer greater opportunities in poor ambient lighting conditions. Plus of course more sophisticated things like weatherproofing, build quality, more and fully rounded aperture blades, better defocusing, AF limit switching etc.

The E-3 and E-510 have an in-camera Image Stabilization system that promises even better results on those occasions where you have to use the ZD300mm hand-held.

We hope this little article has given you food for thought, if nothing else.

If you have any observations please contact me here.

NOTE: This article seeks nothing other than to inform. Only you can decide what equipment you want/need for your use. I/we own most of these cameras/lenses, out of my/our own pocket; I/we have nothing to gain or lose by publishing this article, photographs, examples or opinion.



Posted February 2008 Copyright © 2008 John Foster & Ken Rowe.