E-SYSTEM STANDARD ZOOMS
ZD 17.5-45 v 14-45 v 14-54
what is the difference?
Brief Note: Anyone reading this article must undersatnd that its conclusions are based on several sets of data but from one set of lenses only. Since manufacturing and quality control are subject to human frailties there are bound to be differences in output between examples of the same lens. To be 100% accurate tests would have to use many examples of the each lens in each scenario and we all know that's not going to happen. These tests reflect what the average photographer might expect, out of the box.
Since Olympus introduced their first budget zoom with the E-300, the ZD14-45mm and then late last year the ultra-budget offering with the E-500, the ZD17.5-45 I've been contacted many times for an opinion as to how much 'worse' these budget offerings are compared to the pro-level ZD14-54. It's only in the last month I've picked up a ZD14-45 and so today I've done some comparisons between them. Please understand these are the sort of tests you can easily undertake at home; I don't profess they are scientific in any way but they are representative of 'ordinary' photography. I am quite happy to present the results here as research information to help your decision making process.
I have posted a quite detailed report on the performance of the ZD17.5-45 that came with my missus' E-500 and as part of that test I did some comparable shots with the ZD14-54 'just to see'! You can access that article here, should you wish to read it first. In that test I conclude that the ultra budget offering is a capable little workhorse that is by no means the 'crap' lens that some uninformed observers would have you believe. It is a budget lens with build quality and performance governed by cost. For a zoom lens costing an estimated £70.00 I found its results more than acceptable.
There's nothing in my methodology that needs much explanation. The camera is mounted on a tripod that does not move between shots. Apparent optical differences observed in the results for different lenses is down to lens position on the mount and internal configuration as the tripod head is completely static for each series of shots. The camera is switched off for each lens change. No filters or hoods are used. For this series of test shots I used the following:
* E-1 body with SHLD2 mounted on tripod and shutter activated by RM1.
* Camera (basic) settings: ISO 200; RAW; my personal default settings for E1 general use.
* RAW development via Olympus Studio with identical adjustments applied to each image file.
* The results posted below have not been altered in any way to favour one or other lens.
FULL FRAME RESULTS SET 1:
Three images of my standard test scene - sorry if it gets boring! I endeavoured to time the shots as close together as possible while the sun was obscured.
FRAGMENTS SET 1:
Lens 1. Not so sharp, colour a tad dark.
Lens 2. Slightly sharper, colour a tad washed out.
Lens 3. Slightly sharper again, more definition, colour a tad dark.
CRITIQUE SET 1:
Looking at the full frame results the only discernable difference is in the contrast and colour saturation. To my eyes (and comparing it with the actual scene) No 1 is too contrasty, No's 1&3 are over saturated and No 2 is a little washed out with a slight strange blue/grey cast. However we are being super critical here. None are much better or much worse than the others, though No 2 stands out because of the slight cast.
However, when we examine the fragments (100% crop and re-sized only) we can see areas of blurring (like compression blur) in No 1, definite sharpening from No 1 to No 2 and further sharpening and added contrast to No 3. The perceived sharpening improvements between No 2&3 might be due to either more resolution or more contrast, or a mixture of both; to be honest it is impossible to say. The blurring areas on No 1 are not processing artefacts as such but areas where the lens has been unable to distinguish or define the details. These areas are much less noticable in No's 2&3, though they are there.
FULL FRAME RESULTS SET 2:
The same scene but this time I waited until the scene was in full sunlight to exaggerate the contrast and see what the differece (if any) was in lens performance between reasonably well lit and brightly lit scenes.
FRAGMENTS SET 2:
Lens 1. Not sharp - cannot decipher letters, too contrasty, colour a tad dark.
Lens 2. Much sharper, colour about right, contrast about right.
Lens 3. Slightly less sharp, too contrasty, colour a tad dark.
CRITIQUE SET 2:
In this brightly lit scene that is in itself very contrast laden, the lens with apparently least contrast from the first test (that is lens 2) appears to give the best result. While it might appear to be less sharp when comparing the roofs of the three images above, detailed examination of each image shows lens 2 is marginally the best performer.
When we examine the fragments (100% crop and re-sized only) it's easy to see that in these conditions the ability to resolve detail dropped significantly in lenses 1 and 3 with lens 2 providing the best fragment and best overall result.
FULL FRAME RESULTS SET 3:
This time I've changed the scene. It's early evening, about 7.15pm and the sun has gone. It's just about dusk and the light is poor. I want to see how the three lenses perform in these less than ideal conditions.
FRAGMENTS SET 2:
Lens 1. Average sharpness, slightly cool colour, contrast about right.
Lens 2. Less sharp, colour better, contrast about right.
Lens 3. Sharpest of the three, good colour - warmer, contrast about right.
CRITIQUE SET 3:
In this scene where the light is failing fast and laden with red, all three lenses have done very well. So similar are the results that I had to keep checking the EXIF information to make sure I had one from each lens. I doubt you can tell them apart - I certainly can't. It is only the slightly improving 'warmth' that differentiates them and not sharpness, colour or contrast. The difference is marginal.
When we examine the fragments (100% crop and re-sized only) we see some difference in sharpness of the roof slates and chimney stack. Here No 2 is marginally the worst performer, with No1 showing a slight improvement and No 3 being the sharpest of the three, but the margins are not great by any means.
FULL FRAME RESULTS SET 4:
After spending some hours pouring over the results I decided I'd extend the test to include comparisons with the ZD 11-22mm and the OMZ 18mm. The following day, which was reasonably bright but overcast with typical UK 'milky' sky, I set the tripod up again and took the following 5 images:
FRAGMENTS SET 4:
CRITIQUE SET 4:
I'm really glad I did this extended test. I have now tested and compared FIVE Zuiko lenses at 18mm on the E1. This last test shows just how little difference there is between the ultra expensive ZD Zooms and the 'el cheapo' and for those with an arsenal of older OM glass how the expensive (£1000) 18mm manual lens compares. I asked my missus to look at them all in Photoshop to see if there were any significant differences. After some serious examination the only one she could establish as different from the others was the one taken with the OMZ 18mm; the rest were virtually indistinguishable, and I agree with her. You will notice I've not put comments under the full frames or the fragments as I believe they are unneccessary. The 18mm OM delivers the worst performance, though it is not a disaster by any means.
I took great care to ensure each lens was used at the same setting. I had difficulty registering a focal length of 18mm with the ZD 14-54mm in the 3rd and 4th set. It was either 17 or 19mm. The EXIF information has been carefully compared to ensure aperture and shutter speed were the same for all three lenses in each set of conditions. Only the image from the OMZ deviates from the rest in test 4 with a shutter speed of 1/125th at f8 compared with 1/100th at f8 from the others. I believe this test has been fair and equitable and reflects 'everyday' photography by any competent DSLR user.
The results vary with no particular result standing head and shoulders above the other. In fact the results show different performance by different lenses in varying lighting conditions and reflect the very real circumstances we all find ourselves while pursuing our hobby. That the results vary underlines there is no outstanding winner in this test, or more pertinently, no outstanding loser. It demonstrates the optical performance of each of these lenses at comparable points at either end of their zoom range, are very similar, in fact surprisingly so, for which Olympus must be congratulated. It's genuinely good to know that a cheap Olympus ZD lens does NOT mean a POOR lens. On the other hand it underlines that the Pro-grade lens range is expensive because these lenses will deliver the same performance as their siblings at much wider apertures, offering more photographic opportunities. It is the light gathering capability that costs the money, and not necessarily any additional resolving power. And of course the high grade lenses are significantly more robust, dust and drip proof.
Adding the ZD 11-22mm to the list in test 4 shows just how similar lens performance is, regardless of lens genre, or reputation, or price. I am disappointed to see so much purple fringing (PF) from this lens.
In addition the inclusion of the OMZ 18mm illustrates that older glass can be used and produces comparable results in terms of sharpness, though its colour and contrast are not as good as the modern zoom equivalent. PF is not as bad as I anticipated.
The whole test shows how much contrast affects results. For many decades Olympus have produced good contrasty lenses with optical coatings designed to enhance image contrast, adding to the overall 'perception' of sharpness. However, in high contrast lighting situations they do not perform quite as well.
The slight colour cast evident from the ZD17.5 - 45mm in test 1 is, I believe, the result of single coatings on the budget zoom.
Purple fringing is evident in all results, especially test 4 - and just where you'd expect it to show. However, I don't get excited about PF as it is not a 'digital' phenomena, nor is it difficult to remove if you find it offensive.
For any reader who would like to examine the RAW files that these images are derived from I will be happy to email or FTP them if they ask. You can rest assured I have not attempted to skew the results in post processing; I have no reason to do so as:
(a) I have already invested in the above lenses so I have no axe to grind, and
(b) it might have been reassuring to see that high cost lenses deliver significantly and proportionately more optical performance (but not so).
For those who have not worked out which lens is which, here are the lens identifiers across tests 1 to 3:
Lens 1 is the ZD 14-45mm
Lens 2 is the ZD 17.5-45mm
Lens 3 is the ZD 14-54mm
For test 4 the lenses used are in the same order as above with the ZD 11-22mm used for image 4 and OMZ 18mm used for image 5.
Knowing how good the little ZD17.5-45mm is at close-up work (not macro), I thought it might be interesting to do a quick comparison between it and the ZD14-54mm as it too has good close focus capabilities. I have not included the ZD14-45 as its configuration gives a pretty poor close focus of only 38cms compared to 22cm (14-54) and 28cms (17-45). Once agin the testing process rather surprised me. On the face of it you might think the ZD14-54 will win hands down as it is a better built lens with 22% closer capability than its cheaper sibling; not so. Here are the results:
As with most impromtu 'macro' or close-up work the average amatuer does not have proper macro-type lighting and makes do with what is to hand. (After all, if you are going to specialise in this type of photography you will more than likely buy a true macro lens with matching ring flash). This 'make do' approach is certainly the case here. I lit the subject from the left with a desk lamp and set each lens to FL of 45mm at f11 and adjusted the height above the subject via the tripod head to be as as close as possible but still maintaining good AF response (no hunting).
The ZD14-54 sits physically closer (against the 17-45) by over 31mm measured on the tripod column but the big disadvantage is that the larger and closer lens body blocks out much of the light even though I adjusted the source to compensate. In addition, although physically closer and at the same focal length of 45mm the captured image is smaller by about 15%. And if you are thinking that the lens will be better at FL 54mm, this is not the case as it needs to be lifted higher to enable AF and the final image at FL 54mm is marginally smaller than FL 45mm. In other words the close focus capability of 22cms is not consistent through the zooming range.
The tiny ZD17-45 sits higher above the subject allowing even lighting and also produces a significantly larger image. Compare the two images above and I think you'll agree for this type of work the little ZD17-45 is not only more functional, it actually produces a better result all round. Those getting this ZD 'free' with their E-500 must surely be smiling now! In my opinion it is a pretty good close-up lens for the occassional 'macro type' shot.
For those wondering how far removed from a true macro rendition the two images from the ZD's are, I repeated the exercise with the OMZ 50mm Macro lens which boasts a half life-size image. This 50mm OMZ lens sits at around the same height above the subject as the ZD17-45 allowing even lighting. I estimate the result from the ZD17-45 is 1/4 the size of the OMZ 50mm so it is way off being a macro lens. However, the smaller image viewed against the true macro rendition compares much better than I'd anticipated, and for all but really critical work a quarter crop and enlargement from the ZD17-45 will give a very acceptable macro rendition.
BARREL & PINCUSHION:
I now have a temporary test board to show barrel and pincushion effects. I am acutely aware of this omission in my reviews and have been trying to work around the shortcoming. My target is a little crude but it serves its purpose, for now anyway. As soon as I have an improved target and test set-up I shall repeat these tests. (Results are much in line with what you would anticipate).
OBSERVATIONS ON BARREL & PINCUSHION:
The images above reflect what I expected and what we all knew anyway; the lack of distortion is directly proportional to the more complex the zoom lens structure and its price. In other words (generally) with zooms the more you pay the less distortion you get and vice versa. (In zoom lenses barrelling occurs at extreme wide angle and pin cusion appears at extreme telephoto).
Of course there is more to a lens that pure optical performance and close focus ability. I've briefly mentioned aperture spread above, but also consider the focal length capabilities of each of the 'standard' zooms and the other factors. I've summed up each of the lenses thus:
1. The high grade ZD14-54mm is the best specified in terms of brightness and focal lengths. A 35mm equivalent 28-108mm x f2.8~3.5 with 15 elements in 11 groups offers much - a bright almost 4x zoom with close focus capability of 22 cms (not throughout the zoom range) appears very respectable. Its wider aperture offers more control over depth of field (bokeh) for atmospheric shots as well as more opportunity for handholding in poor lighting conditions. Its construction is far superior being a mixture of magnesium and engineering plastic and is both dust and drip proof, but it is much larger and heavier; weight = 435 gms. Lens barrelling is minimal and well controlled. Handling and aesthetics are more attractive with slightly better features such as a mounting grip and a distance scale (of dubious use). Filter size = 68mm, Price in UK is around £400.00.
2. The low grade (budget) ZD14-45mm is the 'mid' range choice. A 35mm equivalent 28~90mm x f3.5~5.6 (3.25x zoom) with 12 elements in 10 groups it loses out in both telephoto reach and brightness. Close focus is poorer than the high grade option at 38 cms. Its construction is poorer too being entirely plastic (except the mount), but of course it is lighter at 285 gms. Barrelling is quite noticeable and will cause problems with your wide angle images. It has no distance scale. Filter size = 58mm. Price in UK is £150.00.
3. The 'super budget' ZD17.5~45mm is certainly at the bottom end of the choices. A 35mm equivalent of 35~90mm f3.5~5.6 (2.6x zoom) with 7 elements in 7 groups it loses out at both ends to the Pro-grade offering, but only at the wide end to the low grade option. However its close focus capabilities that on paper do not seem especially remarkable at 28 cm throughout the zoom range, in practice prove far superior to the ZD14-54 'Pro-grade' lens. Barrelling is worse than the ZD14-54, but not as bad as the ZD14-45 (it shouldn't be as it is not as wide-angle) but it will cause minor problems in your wide angle images. Its construction is on a par with the low grade option though the lens mount is plastic; its weight is only 210 gms. No hood is supplied (a bad omission in my view). Filter size = 52mm. This lens comes 'FREE' with E-500's purchased in UK & Europe. Estimated price is £70.00.
'Standard' or 'Kit' lenses inevitably receive a lot of attention from their users. It figures therefore that opinions differ widely and reflect not only the quality and capability of the actual lenses involved, but also the aspirations and experience of the user. Having said that I know many E-System users who are not overly impressed by the expensive ZD14-54mm and others who are delighted with their ZD14-45mm. My time and experience with the tiny ZD17.5-45mm certainly says it should not be summarily dismissed as 'rubbish', far from it. I have endeavoured to give you a feel for all three lenses in this article in a totally unbiased manner by illustrating how good they all are, their limitations and where any problems start to arise. I have no axe to grind as I already own all three.
If you are thinking about your first ZD 'standard' lens, upgrading what you already have, maybe adding a back-up lens or (heaven forbid) selling your ZD17.5-45, I genuinely hope this page helps reach your decision.
A SECOND OPINION:
There is a further discussion of the ZD 14-45mm versus the ZD 14-54mm at my good friend Andrzej Wrotniak's site. Our articles are not linked in any way; we coincidentally and independently responded to requests from readers for comparisons. Please read Andrzej's article; our methodology and style are very different (and of course Andrzej is a physicist), but we reach similar conclusions. You can go directly to his article here.
NOTE: This article seeks nothing other than to inform. Only you can decide what equipment you want/need for your use. Bear in mind I own these lenses, out of my own pocket; I have nothing to gain or lose by publishing this article, photographs, examples or opinion.
|Posted September 4th 2006||Copyright © 2006 John Foster|