Zoom lens f/1.8 or faster?
 

Hi. I have the following Canon lenses for my 7D:

50mm f1.8 prime (Nifty-fifty)
10-22mm
28-135 IS
70-200 L
And some other junky ones.

With my video work I see that I'm going to my cheapest lens of the bunch more and more (nifty fifty) because of the shallow DOF and low light abilities. However, I find myself really wishing I had something with some more range, like a 35mm to get closer to a true 50mm (35 x 1.6), but not be stuck with just 35mm.

I'm willing to drop some money into this next lens, but I would like it _NOT_ to be a prime lens, but to have some ranges somewhere between 25mm and 75mm, while I still want it to be as fast as possible.

Is there anything that's a f1.8 or faster with these specs that's NOT a prime (fixed mm)? It doesn't have to be Canon.

Any suggestions?

As far as I know, the fastest 35mm zoom lenses start at f/2.8 and go up. If you want a faster lens than that, it's gotta be a prime.

I can't think of any either.
Steve

all the zooms are at the most f2.8 from what i've seen, i think its to do with lens optics and engineering.. if there was a 1.8 it would probably cost you huge $$$$$!

You have to go prime to get wide angle greater than f2.8, like the Canon 35mm f1.4L

The Panavision Digital Primos open up to a 1.8 or maybe some are even faster. I think it won't be long before the rental houses will have PL adapters for the DSLRs, so you might be able to rent an adapter and lens package for shoots where you have the need (and the budget). But down at the lower end of the food chain where most of us thrive, you've got to go with primes if you want anything faster than 2.8.

That fast Canon 35mm would be an excellent and versatile lens. Canon also has an f1.4 24mm L lens for about the same price as the 35. And there's a much cheaper f1.8 (non-L) 28mm.

Canon has registered a patent on a 17-50 that's f2 thru the range... it won't be cheap.

Going with an F2.8 zoom, or fast primes are really your best options.

Shorter DOF, zoom and better low-light? Sounds like a 5Dm2 w/ 24-70/2.8

Did you know that a 5Dm2 w/ 50mm @ f2.8 and a 7D w/ 30mm @ f1.4 both focused at 2m/6ft have roughly the same DOF? 26.32cm for the 5Dm2 and 23.37cm for the 7D.

Very true. You have to open up more to get the same shallower depth of field because the chip is smaller; conversely you have to stop down less for more DOF. That's one reason I consider the 7D ideal for the type of shooting I do. Since I'm normally alone or with only a soundman on a shoot, I don't have an assistant for follow focus. The 7D gives me good control over DOF so if I need to increase it some, I can without going up too much in ISO. On a recent shoot, for example, I had a subject moving around in the frame left to right and going back and forth to a shelf about 8 feet in the background. Since I couldn't follow focus and keep with the follow action, I went from a 2.8 to a 3.5, guesstimated the hyperfocal distance, and got the whole action in focus by increasing the ISO just enough for that extra stop. With a bigger chip I would have had to shoot at a 4.5-5.6 to get the same DOF, which would have meant raising the ISO even more. I'm not knocking bigger chips--love 'em. But if you don't always have an assistant to follow focus for complex shots (lots of follow action),the shallow DOF can eat your lunch. I like the ability to make it shallow when I want, but I also like the ability to make it deeper as well.

yes you can argue either that the 5d is worse in low light or better..

theres one line of thought that you should never be above f4/f5.6 on a 5d and never above f2.8 on a 7d..

The Power of Focus | Hurlbut Visuals

It's not better worse. It's just that the bigger the chip, the shallower the depth of field and that is something you have to deal with. On bigger crew shoots you'd most likely have an assistant with remote follow focus, or at least a whip. If' you're by yourself, that's more difficult.

That rule would only apply for a given framing (focal length and distance from subject) with a given look as your goal. For a macro shot I might want f/18 and at a long distance, wide open can be just fine.

Those can be good guidelines for a given style of shooting. I'd avoid the word "never" though...

One has to remember that Shane was shooting the Navy Seals film with theatrical release in mind; many using these cameras are posting and viewing their work purely on computer screens often at reduced sizes and have not yet realized how much focus issues magnify when viewed 40 feet across.

For a long zoom (say, 70-200), T2.8 will be plenty fast enough to be able to maintain any kind of focus, without doubt on the larger sensor cameras i.e. 5D and 1D.

BTW Bill, you referenced the Panavision Digital Primos--those were built for the 2/3" format. Panavision has not updated their 35mm Primo zooms in years, the fastest of which remain at a 2.8. This maximum aperture is echoed by most of the PL mount zooms (Angeneiux, Cooke). Also bear in mind that these will ultimately work best on the 7D--they may have partial coverage on the 1D and likely not worth using on the 5D.

Incidentally, you can't rent Panavision lenses without a camera any more, partially due to their lawsuit against Canon and these sensors. Even Shane has to include a film camera when he uses the Primos (the Arri 2C being the least expensive they offer).

I belive fuji has an 18-50 t2 zoom out now in PL mount. No SLR zooms are that fast.