17-40 mm L F4 or 16-35 mm L F2.8

[dangermouse]

I'm looking to get a new wide angle lens for my Canon EOS 300D (poor me, I only have the kit lens). I think a 10-20 mm or the like will be too wide so I was thinking of the 16-35L or the 17-40L. Also worth considering, I might get a s/h 5D next year.

I want to take great landscape photos, mostly locally (I live between Cambridge and Huntingdon) and would like to get into HDR. from time to time I might go further afield (around the UK).

So, I would buy a 17-40L new (~£470) but could only afford the 16-35 s/h at a stretch. There's one a very reputable dealer whom I trust for £730. I calculate the 16-35 is actually ~25.6-56 whereas the 17-40 is 27.2-64. Will I notice the difference at the short end?? Is it worth the extra for the F2.8 over F4?? I guess most of my shots will taken at small apertures on a tripod.

Advice most appreciated.

David

[Colin Southern]

Hi David,

I suspect that a lot of people "mis-understand" wide-angle lenses. As a general rule if they're used simply with the horizon centered to capture a panoramic type scene then the field of view is so wide that light falloff (not to be confused with vignetting) almost becomes a limiting factor. Personally, I find them far more useful in composing agressive shots where you can magnify the significance of relatively small foreground objects by being able to get relatively close to them.

So to answer your first question: "Will I miss the extra couple of mm (allowing for crop-factor)" when using the 17-60/4" ... probably not.

With regards to the 2 lenses, both offer the potential for very high image quality, but with the 16-35/2.8 being sharper around the edges. Although the 17-40/4 is a stop slower, landscape is typically shot at much smaller apertures - so this isn't likely to be significant.

One area that MAY be significant though is the potential for vignetting when using filters (especially stacked filters). If you want to shoot world-class landscape then inevitably you reach a point where you start using GND (Graduated Neutral Density) Filters - often stacking them. Some people initially think "what's the big deal with a bit of vignetting - it's easy enough to fix in post processing" - but stacked filter will take you past "severe vignetting" into "outright lens obstruction" category. If you're using stacked filters then you'll be "vignetting limited" with both lenses, but you'll be able to go considerably wider with the 16-35/2.8 before this occurs. (in fact often its a case of mounting the filters and then zooming in until vignetting gets to a point where it can be corrected in post-processing.

So to answer your 2nd question (regarding which one), "it really depends on what you can afford and how you're going to be using it - now AND in the future" ...

If you can buy a 2nd-hand 16-35/2.8 that's optically perfect then - personally - that's what I'd go for, but in reality, it's unlikely that anyone would want to take a loss on a state-of-the-art lens (unless they simply needed the money) - in which case their loss could be your gain. However if you can't envisage yourself getting into Lee type filters (which - when you use quality brands like Singh-Ray cost a lot of money in their own right) then you'd probably be better served by the 17-40/4.

At the end of the day though, I'd suggest not getting too hung up over the decision - it's not as if one is going to be totally right and the other totally wrong - there is a HUGE overlap between the two.

Hope this helps!

Cheers,

Colin - pbase.com/cjsouthern

[dangermouse]

Thanks Colin for a really useful and informative reply. I too want to use one of these lenses to get some real in your face foreground interest - so I very much liked your shots.

One thing I would have never guessed is that when using (stacked) filters, and zooming out, the 17-40mm L lens will become vignetting-limited before the 16-35. Why is that??

Cheers,

David

[Colin Southern]

Hi David,

I haven't really given it much thought to be honest - I assume it's due to the 16-35/2.8 being 1 stop faster and 5mm wider.

I did hear a rumour that one of the reasons Canon went to 82mm diameter was to address vignetting concerns, but I have no idea if there's any truth to that, or if it's just speculation.

Personally, I like to think of the 16-35/2.8 as being the "new and improved" 17-40/4 - apart from the small difference at the long end (a non issue when you team it with the 24-70/2.8 and 70-200/2.8 lenses - the only other "downside" is the price.

Let us know what you decide!

Cheers,

Colin - pbase.com/cjsouthern