ZD EC 14
teleconverter lens on test
Of all my photography, telephoto work probably represents the highest percentage. This likely reflects the area in which I live and undertake the majority of my shots; deep in the Yorkshire Dales. Here in the sweeping majesty of rolling hills and heather clad moors the natural perspective is already that of wide-angle. Putting a wide-angle lens on a camera to capture an existing wide-angle scene can be overkill. As I explained to a friend once "all wide-angle lenses give me is more blue at the top and more green at the bottom" and I can't think of a more pertinent way of putting it. If I lived in a more 'scenically challenged' area I have no doubt my preference would be different. However, I don't, so it follows that a tele-converter, giving additional reach to existing lenses, would be an early addition to my E-System armoury. Having said that I was never greatly enamoured of OM converters, in particular the OM 1.4 times unit which promised much but failed to deliver. With this in mind, It was with some apprehension I ordered the EC14.
About 9 days later my EC14 arrives. Packed very securely in the silver E-System box the EC14 comes with front and back caps and its own little lens pouch made from black leatherette and suede material. I think these new style pouches are simply awful. The old OM system pouches were much superior but they did lack a hard base so, I suppose, (grudgingly) this new design does the job. The EC14 is made from dense machined alloy, quite heavy, well made and beautifully finished, matching the black finish on other ZD lenses. The two outer facing elements of the six that make up the converter are obviously coated - you can easily see the multi (coloured) coating. The element that faces the rear of the attaching lens is masked to the 4/3rds aspect; something I wasn't anticipating. On the body of the converter is placed an independent lens lock/release enabling the user to dismount the attached lens, leaving the converter fitted to the E-1. And of course there are the 9 pass-through pickups for transmission of lens information to the E-1. I begin to see why this piece is so expensive. BUT, how will this converter perform? Let's go see shall we?
Following my example shots with various OMZ's on the E-1 Body (you can see these here), I decided to use the same target in preference to my flat 2D test chart used previously. The procedure is simple. I set the camera on a tripod at 100 foot from the focus point, put it on P, set the mirror up for 3 seconds and use the remote control RM-1. E-1 settings are: ISO = 200; Sharpness -1; Saturation 0; Contrast 0; Colour Space sRGB; all else except mirror OFF. Images are recorded at SHQ and are reproduced here with no post-processing other than saving at 72 dpi to reduce size for web display purposes. If anyone wants full versions for critical analysis please contact me here.
IMPORTANT: While the reduced versions shown in this article serve for illustration, I have had the benefit of examining the full versions in great detail. Be assured that any significant differences between comparable images will be pointed out whether or not such differences are visually voided in the reduction process.
Test conditions today (dull) dictate that in P mode the E-1 will use the lens' maximum aperture throughout, which is what I want.
I take 5 shots with the ZD 50-200mm at 50, 70, 100, 150 and 200mm. I mount the EC14 on the E-1 followed by the 50-200mm and repeat the exercise taking 5 shots at the effective focal lengths of 70, 98, 140, 210 and 280mm. (Remember to double these to 'convert' into 35mm equivalent thinking).
I'm only showing the results from 50mm/70mm (widest FL of the 50-200mm lens) and those at 200/280mm (long end of the 50-200mm lens) for no other reason than I can't think any intermediate settings will be used much when using a EC14.
There was no-one more curious than me to see the results. Having done a series of tests with Telephoto OMZ's on the E-1 body I have an idea of the quality those lenses can produce (or not as the case may be). Just to remind you of the relationship between ZD and OMZ, the unconverted 50-200mm at 200mm is the equivalent FL of the OMZ 200mm f4 or f5 prime, while the converted 50-200mm at 280mm (more difficult to match) is approximately the equivalent of the OMZ 300mm f4.5 prime.
OK, let's take a look at the results;
No 1: ZD 50-200mm at 50mm
Of course you have to bear in mind that you lose a stop or there abouts with the EC14 mounted. When comparing shots 3 & 4 please remember that the result would naturally 'sharpen' as the effective aperture drops from the max f=3.5 in image 3 to f=4.9 in image 4. I believe this is what we are seeing here.
My tests confirm that the accurate light drop in these (poor) conditions, as registered by the exif information, between shots 3 & 4 is 1.4. This is slightly better than the official Olympus literature that indicates the EC14 converts the 50-200mm f=2.8-3.5 to 70-280mm f=4.0-5.0 (a 1.5 loss). I read somewhere, (my memory is terrible), that the easiest conversion is to multiply both focal length and aperture by 1.4. This is very simple and appears to hold good for the Zuiko Digital range of lenses. But from my past experience with analogue converters on film cameras this straightforward conversion was not quite as clear cut. However, my physics leaves much to be desired so I'll leave it to others to do the maths.
It is plain the EC14 is capable of excellent results, but how does the combination of ZD zoom + ZD tele-converter compare to the OM Zuiko prime telephoto's mounted on the E-1?
Let's see shall we?
No 5: ZD 50-200mm at 50mm, no tele-converter
NB: The OM 300mm is a six element simple telphoto prime whereas the ZD 50-200mm is a complex zoom with 16 elements, 3 of which are ED glass and the TC14 adds another 6 elements; 22 bits of finely machined and polished glass through which the light must pass unincumbered.
Purely for fun: The OM 300mm in the 90's cost £900; the combined cost of the ZD 50-200 and EC 14 is £900; a remarkable coincidence? However the ZD is auto focus and an 'intelligent' lens that passes information to the digital body; the 300mm is just a lens/paperweight/doorstop (I jest).
But the purpose of the second part of this article is to compare an OM Zuiko Prime Telephoto with a Zuiko Digital Zoom lens AND a tele-converter. I believe these results show just how far the Olympus lens makers have come. Anyone with experience of analogue converters will be well aware of the dramatic loss of light and resolution that occurs when using them on film cameras, regardless of what the makers told us. (They insisted a 1.4X converter lost one stop, and a 2X lost 2 stops). I don't think I'm alone in disagreeing with their claims.
However, with the EC14 in conjunction with ZD lenses, there appears to be nothing lost in terms of resolution and a minimal loss of useable light. If this is what 21st century lens making combined with digital technology is bringing us then I can't wait for more!
I'm converted too! These results are alarmingly good. I admit to being proven wrong. I genuinely thought any tele-converter would bring with it an inevitable loss of resolution. This is clearly not the case. Well done Olympus. For anyone like me who tends to use the telephoto end more than wide-angle, an EC14 is an excellent way of increasing your lens armoury at a 'reasonable' cost.
Prices: UK = £299 - £345; US = $385 - $425.
|Posted July 2005 14:04||Copyright © 2005 John Foster|