Canon 17-40mm L or Canon 20mm Prime?

[eyst]

Hi guys! Sorry about making ANOTHER lens vs lens thread, but I have a relatively specific question.

I'm upgrading from my 300D into a 1DMKII, right now i'm moving from the equivalent 28mm into something wider, which is easier to get on the 1.3 crop factor 1DMKII. My needs are...

- I will be using it almost always at minimum aperture, therefore the wide aperture on the prime lens is not important to me.

- I will be using it on the widest angle setting possible. So when looking at the 17-40mm look only at the 17mm end.

- This is going to go on the 1DMKII, not the 300D.

- Sharpness is VERY VERY important.

- Minimising Barrell Distortion is VERY VERY important.


If the 17mm has LESS distortion than even the 20mm prime, and it's they are both relatively sharp as each other (at wide angle setting) than i'd definately opt for the 17.

However... I heard the 17-40 at 17mm isn't all that sharp, and being more wide angle i'd suspect it to show more barrell distortion than the 20mm prime. I just like the sound of a prime lens because it gives me the impression that it would have far superior performance over the 17-40mm. But like I said, the sharpness and barrell distortion mean alot more to me than getting just alittle bit more wide angle. Both lenses end up giving me more coverage than the kit lens at the moment anyway when I put these new lenses on the 1DMKII.

I'm not knowing which one of these lenses to get, if you couldh elp me out that would be great!

If you're curious as to what strange application i'm needing this wide angle lens for, it's for this http://home.iprimus.com.au/easton/motion/motion8.jpg then you'll know why I need this particular type of wide angle. Small aperture, big F number, wider angle, minimum barrell distortion possible and maximum sharpness attainable.


Thanks guys!

 

[oeyvind]

If you don't want any distortion... what you want is a TS-E lens like the 24mm TS-E.

 

[Kit]

I use both 17-40 and the 20. The 17-40 at 17 does have visible barrel distortion but sharpness is good. For what you do, the 17-40 gives you that extra convenience and flexibility for composition. So I would go for the zoom. You don't really need the faster prime since you said you wanted deeper DOF. That being said, should you go for the 20, mine's for sale.

 

[Kit]

A shot using the 17-40 with a 10D. Barrel distortion is quite visible as mentioned before but don't think its as big an issue for what you do though.

 

[kiwi2]

I've used both lenses. It's not quite fair to compare the 17-40mm at 17mm vs the 20mm bcos they are at different focal lengths. There is bound to be some sort of distortion when you go lower than 20mm. The question is how well-controlled it is. In my experience, the distortion in the 17mm is acceptable. The distortion in the 20mm is minimal too. Both are excellent lenses IMHO. I think you should be more concerned with the focal length that is suitable for you most of the time when you put the lens on the 1D MkII.

As for sharpness, I can vouch both lenses are sharp. But if you want to go into the finer details which one can resolve better and all that, I'm not quite in the position to comment because I don't quite believe in scrutinizing MTF graphs and choosing lenses based on that. Those are just lab-condition tests. Good to read but take it with a pinch of salt.

As for prime lenses being sharper than zooms (I mean respectable ones, possibly L and not kit lenses), there might be some out-dated lies in this view. Maybe 20 years ago, we can think this way. But given the sophisticated lens design these days, some primes are losing their popularity. The only reasons I should think people stick to primes are that they are relatively cheaper, the focal lengths are frequently used and they are light. Primes or good zooms are sharper is hard to dispute sometimes. Even if one can resolve (no pun intended) this issue by some elaborate tests, the question remains: How much sharper?

Take for example the 200mm f/2.8 and any of the 3 Canon 70-200mm L lenses. Theoretically we would expect the prime to be sharper because of its less complicated lens design. But really, how much sharper is it? In the end, what you lose out really big from the primes is the convenience of changing focal lengths by zooming while remaining at one spot. Some will convince you that primes force them to move around and see differently, but this is not a complete or satisfying reason I'd choose a prime over a zoom.

Much said, with so many new USM and L lenses for pros and advanced amateurs alike, some primes are losing their popularity (and indeed difficult to sell 2nd hand) for the reason I mentioned above. Eg: The 35mm f/2, 200mm f/2.8 and... yes, the 20mm f/2.8 you're contemplating.

P.S. Just to add, the 17-40mm gives a slightly warm colour cast.

 

[oeyvind]

Take for example the 200mm f/2.8 and any of the 3 Canon 70-200mm L lenses. Theoretically we would expect the prime to be sharper because of its less complicated lens design. But really, how much sharper is it? In the end, what you lose out really big from the primes is the convenience of changing focal lengths by zooming while remaining at one spot. Some will convince you that primes force them to move around and see differently, but this is not a complete or satisfying reason I'd choose a prime over a zoom.

I think you should compare a prime like 200/1.8 or any of the tele.

 

[eyst]

Thanks guys!

From what you guys have said I think i'm going to opt for the 17-40mm, it sounds like the only advantage of the prime is being that it's cheaper and lighter.

If at 17 i'm getting too much distortion, I can always go as far up as 21mm again before I get as much coverage as I originally did with the kit lens + 300D combination. And i'd assume i'd get a much sharper and higher quality result with this than on my 300D combo. That alone is enough to warrant the upgrade, not to mention the extra megapixels on the 1DMKII.

 

[arm]

In digital mode, most distortion can be removed in software unless it is a complex type. Even fisheyes can be adequately corrected.

See: http://luminous-landscape.com/reviews/imagealign.shtml

 

[sequitur]

if you don't mind the slow f-stop
get the sigma 12-24.. it has really very little distortion, lesser than a 17-40.


i personally like distortion at wide angles because i don't usually shoot landscapes. even if i do, the distortion sort of gives me a very "wide-angle" feeling which i like. that said, it's all personal preference. personally i like lenses that have light fall-off at the corners too (nope none of the mentioned lenses have this).


anyway, at the end of the day, it's what you shoot and what you like to shoot.

by the way the sigma 20/1.8 is a good prime to consider. stopped down (some people say) it's as sharp, if not, sharper than the 17-40 f4.

 

[oeyvind]

if you don't mind the slow f-stop
get the sigma 12-24.. it has really very little distortion, lesser than a 17-40.


i personally like distortion at wide angles because i don't usually shoot landscapes. even if i do, the distortion sort of gives me a very "wide-angle" feeling which i like. that said, it's all personal preference. personally i like lenses that have light fall-off at the corners too (nope none of the mentioned lenses have this).


anyway, at the end of the day, it's what you shoot and what you like to shoot.

by the way the sigma 20/1.8 is a good prime to consider. stopped down (some people say) it's as sharp, if not, sharper than the 17-40 f4.

12-24 has more distortion than 17-40!

 

[sequitur]

12-24 has more distortion than 17-40!

dunno

seen a test somewhere where the dude shot landscape shots on a film camera using 12-24

there's the wide angle perspective but when he shot the standard window blinds test - it was straight across

 

[oeyvind]

dunno

seen a test somewhere where the dude shot landscape shots on a film camera using 12-24

there's the wide angle perspective but when he shot the standard window blinds test - it was straight across

http://194.100.88.243/petteri/pont/Reviews/a_Sigma_12-24_f4.5-5.6/a_Sigma_EX_12-24_f4.5-5.6.html

if u shoot straight, there almost no distortion on 16-35 or 17-40 as well... duh

 

[Kit]

Don't know about the 12-24 being a prime but I've got some unusual results from the one and only I've tried out so far. At both 12 and 24, the lens seemed ok stopped down but at 17, sharpness falls significantly even stopped down.

As mentioned before, the 17-40 does display some barrel distortion.

 

[ST1100]

If you don't want any distortion... what you want is a TS-E lens like the 24mm TS-E.

TSE does not correct barrel/pincushion distortion, which is caused by lens optics; it corrects perspective distortions, caused by camera/subject positioning.

 

[oeyvind]

TSE does not correct barrel/pincushion distortion, which is caused by lens optics; it corrects perspective distortions, caused by camera/subject positioning.

sure... but the fact is all the distortion that one see here is caused mainly by that.

 

[kiwi2]

Thanks guys!

From what you guys have said I think i'm going to opt for the 17-40mm, it sounds like the only advantage of the prime is being that it's cheaper and lighter.

If at 17 i'm getting too much distortion, I can always go as far up as 21mm again before I get as much coverage as I originally did with the kit lens + 300D combination. And i'd assume i'd get a much sharper and higher quality result with this than on my 300D combo. That alone is enough to warrant the upgrade, not to mention the extra megapixels on the 1DMKII.

Yes, I should think the 17-40 would be more suitable for you. The 20mm ain't cheap brand new and for a few hundred $ more, you can get an L zoom. Unless you can get a used 20mm for a good price in the region of S$500 or so. Even then, you have to convince yourself that this lens will be on your camera body most of the time (because you feel comfortable with the focal length) or that you need the f/2.8. Else you might find yourself the inconvenience of having to change lenses very often. Worse, it'll be a white elephant.