Everyone who enjoys a reasonable proficiency in the beautiful German language is aware of the concept of the Eierlegende Wollmilchsau. This highly theoretical animal, the literal translation of its name being “egg-laying woolmilksow”, would provide the lucky owner with wool, milk, eggs and pork, all from one source. The term is often used to highlight the fact that a certain product is unable to fulfil all wishes and excel on every single aspect of its use, and the prospective owner will have to compromise on some features. Photographically speaking, an Eierlegende Wollmilchsau would be something like a small, light, full-metal, weather resistant 12-450 mm f/1.4 zoom with excellent image quality and a $100 price tag. Unfortunately, physics is a little bitch, engineers are no magicians and companies operate for profit, so we won’t be seeing anything like that … ever.

The reason I have recently been pondering on that magical animal is because I am considering upgrading one of my lenses. Over the past years I have acquired a couple of new lenses – 35 and 50 mm primes and a 55-300 mm tele-zoom. However, for landscape and outdoor exploits I still primarily rely on Pentax’ standard kit lens, the DA L 18-55 f/3.5-5.6 WR. While it certainly served me well for the past five years, I am convinced that I have outgrown it and it does not deliver the image quality my K3 deserves. Recently I have got more into mountaineering and outdoor activities. I am an active member of my university’s mountaineering club, and am spending a lot of time in the Scottish Highlands, which may well be my favourite region on earth. So I am looking for a lens that can deliver decent image quality across the frame at a rather wide end (less than 18 mm on APS-C), is long enough to fill the frame with climbers up on a wall (ideally > 70 mm) and is rugged and can withstand the often fickle and hostile Scottish elements.

What I want

High optical quality. I’m not looking for professional Canon L grade quality, but it should be significantly better than my current kit lens. Sharpness and micro-contrast are my primary concern, but flare resistance, CAs etc. should not be too horrendous either.

Useful focal range. As I want to cover everything from landscapes to climbing, I need wide-angle to moderate tele. 18-50 is the minimum here, something like 16-85 would be perfect.

Weather sealing. That’s a big one, for obvious reasons.

Fast aperture. This is really a rather secondary factor. It would come in handy when it is getting dark and I need reasonably fast shutter speeds, but how often will I photograph base jumpers at dusk? Not that often, I assume.

Fast and silent AF. Like all of Pentax cheap lenses up to this year the DA L 18-55 WR features a screw-drive AF. That thing is loud (think ‘electric screwdriver’) and not exactly fast, so something silent and fast would be a blessing. It is not a must, but would certainly come in handy for shooting sports.

Reasonable price. That is the obvious crux – I can get everything listed above, but it will cost a lot. I am on a student budget, and that means I am looking at something around €400 ideally. Going over €500 would hurt.

The candidates

I have already ruled out the Pentax HD DA 20-40 f/2.8-4 Ltd. due to it not being versatile enough, the DA 16-45 f/4 for the same reason plus the wobble issue, and the DA 18-135 f/3.5-5.6 due to its mediocre optical performance. I have not yet been able to handle any of the lenses listed, so everything I write is based on a wide range of reviews online.

Pentax HD DA 16-85 f/3.5-5.6 DC WR

My favourite. Best focal range out of the bunch, high build quality, comprehensive weather sealing, a very high image quality across the frame and a fast and silent AF. The lack of a constant f/2.8 aperture does not matter much, and I would immediately get this lens if it were not for the price tag – €600 really is a bit much for a student on a budget.

Pentax DA 16-50 f/2.8 SDM AW

Pentax top-of-the-line standard zoom offer a constant f/2.8 aperture, even better weather sealing than the DA 16-85 and superior build quality. The optical quality seems to be good, albeit not as good as one would expect from a €850 lens, especially on the edges. The AF is silent, but not very fast, and the focal range okay, but the aforementioned retail price rules this option out immediately.

Sigma 17-70 f/2.8-4 ‘Contemporary’

That one is tempting. The AF is fast and silent, it has a variable, but fast aperture, the focal range is better than the rest of the bunch apart from the DA 16-85, he build quality is good and the image quality is apparently on a very high level. What keeps this lens back is the lack of weather sealing and the fact that most reviews note distinctly soft edges at the wide end that do not sharpen up upon stopping down. That really is a bummer for my landscape photography ambitions. At €400 this lens is a very realistic option though.

Sigma 17-50 f/2.8 HSM

The second Sigma comes with a shorter focal range, but very high image quality and without the weak edges at the wide end. The AF is fast and silent and the build quality decent. As all the third party options in this list, it does not feature weather sealing. It usually retails at around €350, so definitively within my budget.

Tamron 17-50 f/2.8 non-VC

The Tamron is one of the most popular options for people who seek to upgrade from their kit lenses. Optically it seems to be on a similar level to the Sigma 17-50 f/2.8, albeit some reviews see the Sigma slightly ahead. In terms of focal range, build quality and the lack of weather sealing it is virtually identical to the Sigma. Where it does fall back is the autofocus – while the CaNikon versions of the lens feature a built in AF motor, the Pentax version uses screw-drive AF from the camera. Oh for god’s sake, which year is it?! That thing is loud and annoying … At €290 it is the most affordable of the bunch though.

So … which one?

You tell me! I certainly cannot afford the Pentax 16-50 f/2.8, so goodbye to that one. The Sigma 17-70 f/2.8-4 is tempting, but soft edges are a big Nono for landscapes, so that one is off the table too. Between the Sigma 17-50 f/2.8 and the Tamron 17-50 f/2.8 the latter is €60 cheaper, but I really want to leave the screw-drive behind. So if pressed, I would go for the Sigma.

That leaves the Pentax 16-85 f/3.5-5.6 and the Sigma 17-50 f/2.8. Image quality wise they are probably pretty close. The Pentax has the more versatile range and the weather sealing, the Sigma has the constant f/2.8 aperture. And the Pentax costs €600 vs. the Sigma’s €350. My brain yells “Sigma!”, my heart whispers “Peeentaaax!”. So the choice is between saving up a bit more, waiting for Christmas and maybe being lucky on a cashback promotion for the Pentax, or simply going with the Sigma. As always I have this weird gut feeling that I will go for the better option …

Source for title image: Georg Mittenecker under the CC BY-SA 2.5 license