I've been shooting in a lot of dark slot canyons recently, and I find myself lusting after a small, ef-s wide angle prime that is between f1.4 and f2. I'd be happy with anything between 12-18mm. I know Canon doesn't have one out yet, anyone think there is enough demand for something like this in the future? Maybe from a third party, like Sigma? What alternatives are out there for low light, ultrawide, and lightweight?

You're looking for an EF-S lens, but your profile lists a 5D.

Wouldn't you need an EF lens?

, sorry about that, need to update the profile I guess. I have a 5D, 40D, and an XT. What I am really after is a superlightweight combo for the XT, that can get me wide and fast aperture. Unfortunately, it looks like a pipe dream...

I have a hard time taking the 5D through the canyons, because it is heavy, and the abuse intimidates me. But a 5D mated to a 35 f2 or 28 1.8 does work well, and I've used it before. Just looking for something similar, but XT style.

The 15mm fisheye is about as wide as it gets, or there's the Sigma 8mm f3.5. But to have something that wide with that big of an apeture.. I'd think the lens would have to be enormous and weigh half a ton.

Hi Will, thanks for commenting.

The 15 is actually a good compromise, but still not f2 fast... That big old front element sure is awfully exposed too... But I have used it, and it worked purdy well.

As to the size issue, an EF-S lens that is that fast would be much smaller than an EF lens, simply because the image circle would be so much smaller, so the optical elements are not nearly as big. I am no optics expert though, but it seems like it wouldn't be that difficult to put together a fast wide prime for a cropped sensor. Maybe it is though?

For example on weights, a 17-55 2.8 is similar to a 24-70 in FOV and aperture on their respective bodies, but the EF-S weighs 1.4lbs, compared to 2.1lbs for the EF version. Or compare the 50-150 2.8 Sigma with a 70-200 2.8 Canon. Sigma is 1.7lbs. Canon is 2.8lbs. Canon 10-22 is 13.6 ounces, the 17-40 is 17.5 ounces. Not perfect comparisons, but it shows the difference is significant.

That is one of the reasons I would like to keep the crop sensor around, it should allow for lighter weight systems. I guess my question is this: is there a reason why a fast ultrawide digital lens hasn't been designed yet? Is it that the engineering is just that much more difficult?

I think one issue is that with an extremely small DOF, that it would in a way negate the purpose of a wide angle lens where you want to get a lot in the shot because a lot of it probably wouldn't be in focus. Something to consider anyway.

There is no such lens as you describe.

You might want to try the 10-22. It's one of the best wide angle lenses made for any format, IMHO. While it lacks a fast aperture, few practical situations tend to require high speed at these focal lengths.

Have you considered a small tripod?

Will Patterson wrote:
I think one issue is that with an extremely small DOF, that it would in a way negate the purpose of a wide angle lens where you want to get a lot in the shot because a lot of it probably wouldn't be in focus. Something to consider anyway.

True, but with a smaller image sensor and circle, DOF is also increased. A super wide on a crop sensor would still have substantial DOF. But that isn't what I'm after. I want a fast aperture, so I can have higher shutter speeds, i.e. to stop motion (such as people). I can always stop down if I need to.

garyvot wrote:
There is no such lens as you describe.

You might want to try the 10-22. It's one of the best wide angle lenses made for any format, IMHO. While it lacks a fast aperture, few practical situations tend to require high speed at these focal lengths.

I realize there is no such lens. The question is more hypothetical. Is there a demand for this type of lens? Is it practical to manufacture? From what I am reading, it appears there isn't much high demand for this type of lens. I want it, but perhaps the cons outweigh the pros.

There are practical situations where fast shutter speeds are critical, which is why I'm interested in a super wide with a fast aperture. (i.e. stopping motion in low light in slot canyons...)

invalid2 wrote:
Have you considered a small tripod?

Yep, carry one frequently. But that doesn't give you a larger aperture, or faster shutter speeds. I guess when sensors start recording at ridiculously high ISO's, I'll have my solution with my current lenses

Anyways, interesting to hear what people think. It sounds like there aren't many people who care for a fast ultrawide. Maybe I shoulda posted this as a poll

It's very difficult to create UWAs.

It's very difficult to create fast lenses.

The combination is nasty. Look at the 24mm F/1.4... Hardly the optical performer. While an EF-S would be a smaller image circle, the complications of designing UWAs still is retained due to the higher pixel density (and therefore pickier sensor) of the XTi.

I doubt it's impossible. That said, I doubt there's much demand for a soft 10mm F/2 that needs to be stopped down to F/8 to yield sharp corners. Most landscape photogs tend to live by their tripod– and be thankful you aren't in the 4x5 days, when you lived with your tripod on your BACK.

If you're looking for a solid compromise, try the panasonic wide format point and shoot. It's portable, affordable, and shoots wide.

Or you know, go out and buy a noblex and have a helluva lotta fun.

24mm 1.4 is probably the closest thing--perhaps it's not great optically compared to a 135mm L or something but it's a very good lens! But of course you'll need to bring your 5D. Would be an awesome combo though if you like a wide view AND narrow aperture.

In defense of the 24L, mine is great, though when new out of the box, it consistently back-focused. Took two trips to Canon (CPS) to resolve.

Some lenses seem to be harder for Canon to manufacture consistently well, but that doesn't mean the lens design itself is poor.

It's so difficult making an UW to start with let alone a super fast one. Be happy with the new 14 f/2.8L II or get the impressive Sigma or Tamron 14 f/2.8. The Tamron is supposedly an damn fine lens if you can't afford big dollars.

There's some stellar Leica and Zeiss primes too, but big dollars.

You aren't likely to see a super wide (for crop cameras) f/2 or f/1.4 prime. First, super wide lenses don't generally get apertures like that. Look at the front end of a super wide and I think you'll understand why. Second, I doubt that Canon would have much of a market for a _prime_ lens in the super wide range that only worked on EFS bodies.

I think f/1.4 to f/2.0 is asking a bit much and f/2.8 might be more realistic and would also allow it to be a reasonable size (not to mention price).

I'm not sure if other people want a lens like that but if Canon introduced something like a 15mm f/2.8 EF-s (equiv FOV to 24mm), I personally would be one of the first to place an order. My standard travel / "on-the-go" kit would become crop body + 15 f/2.8 + 24-105L covering everything I really need without much bulk. I know the 10-22 would serve the purpose also, but the prime would likely be smaller and would probably outperform optically to some degree (and yes I know the 10-22 is good).

... and I would guess that a (non-L) 15mm f/2.8 EF-s could be made in a similar size to the current EF 20mm f/2.8 ? ... not sure