Questions about lenses and filters

[Norm12]

I have a Canon Rebel 4ti. I would like an opinion on whether I should purchase a EF-S 10-22mm f/3.5-4.5 USM Ultra-Wide Zoom for $599 or wait until the Canon EF-S 10-18mm f/4.5-5.6 IS STM Lens becomes available for $299.

My current lenses are all 58mm thread size so I am wondering if I wanted to buy a lens that was a higher thread size (62mm or larger) and I used an adaptor to attach my 58mm circular polarizer will that in any way interfere with the picture I am going to take?

Thanks in advance and please know I am new to DSLRs and just a hobbyist to start out with.

[TCampbell · Accepted solution]

You can put a larger diameter filter on a lens using a smaller filter, but not the other way around.  For example... my circular polarizer has a 77mm thread diameter, but my 100mm macro lens only calls for a 67mm thread (the filter is larger than the lens needs).  For THAT lens, I have a 67 to 77mm "step up ring".  

If you attempt to put a smaller filter on a lens that wants a larger size, you'll have dark corners caused by the edges of the filter being in the shot.

The new lens is essentially a cost-saving lens.  The STM motors are not as fast as the USM motors (the EF-S 10-22mm f/3.5-5.6 has a USM motor).  Also the 10-22 gathers a bit more light (f/3.5 at the wide end vs. f/4.5).  

The two lenses have nearly identical MTF curves, but considering the main curve is taken at wide-open and the 10-22 has a lower focal ratio, the 10-22 is probably actually a little better optically.

In other words... perhaps the only reason one might wait for the 10-18 to be available in stores is because it's price point is a bit lower.  We haven't had anybody do a direct comparison yet, but my "guess" (and that's all it is since I haven't seen the lens either) looks like the 10-22 is still probably the better lens.

One nit... I use wide-lenses for wide-field images of the sky at night.  There's not enough light to auto-focus so I do use the focus indicator on the lens to carefully dial in the focus to "infinity" for the shot.  The 10-22mm has a focus distance indicator on the lens... the 10-18 does not.  

[Skirball]

I'd probably grab the 10-22 from Canon, refurbished for $440:

http://shop.usa.canon.com/shop/en/catalog/lenses-flashes/refurbished-lenses/ef-s-10-22mm-f-35-45-usm...

I haven't been following "The Year of the Lens" very closely, so I don't know how the 10-18 is measuring up.  If it's markedly sharper than the 10-22 then I would consider it, otherwise I'd stick with the 10-22.  I know it's a good lens,with a long history of praise.  With new lenses you never know how it's going to perform in the long run.  The 10-22 also goes slightly longer, and I have to say that I have used the lens at 22 mm more than a few times.  It's also 2/3 a stop faster.

The IS on the 10-18 may make up the slower aperture for some, but personally I don't think I'd get much use out of IS on an ultrawide.  I frequently have my camera on a tripod if I'm shooting UWA.  But that's not to say everyone shoots the same type of photography.  I do love to use my UWA for travel, so the IS would be nice for dusk/night shots.

There's not much you can do about filter size. An UWA is going to be wider than 58mm.  I prefer sticking to 58mm and 77mm, because most of my lenses are that size, but if a great lens came out with an alternate size I wouldn't hesitate.  You probably won't be putting many filters on an UWA anyway.

[Skirball]

One note: if you get the 10-18, and decide to get filters, I would consider buying 77mm filters and using a step up ring. 62mm is an odd size and if you stick with photography you'll no doubt own a 77mm lens in the future.  UWA also suffer from vignetting when using a filter and the additional width would help with that (you would need to get a well made step up ring to make sure you don't get it from that).

[TCampbell · Accepted solution]

You can put a larger diameter filter on a lens using a smaller filter, but not the other way around.  For example... my circular polarizer has a 77mm thread diameter, but my 100mm macro lens only calls for a 67mm thread (the filter is larger than the lens needs).  For THAT lens, I have a 67 to 77mm "step up ring".  

If you attempt to put a smaller filter on a lens that wants a larger size, you'll have dark corners caused by the edges of the filter being in the shot.

The new lens is essentially a cost-saving lens.  The STM motors are not as fast as the USM motors (the EF-S 10-22mm f/3.5-5.6 has a USM motor).  Also the 10-22 gathers a bit more light (f/3.5 at the wide end vs. f/4.5).  

The two lenses have nearly identical MTF curves, but considering the main curve is taken at wide-open and the 10-22 has a lower focal ratio, the 10-22 is probably actually a little better optically.

In other words... perhaps the only reason one might wait for the 10-18 to be available in stores is because it's price point is a bit lower.  We haven't had anybody do a direct comparison yet, but my "guess" (and that's all it is since I haven't seen the lens either) looks like the 10-22 is still probably the better lens.

One nit... I use wide-lenses for wide-field images of the sky at night.  There's not enough light to auto-focus so I do use the focus indicator on the lens to carefully dial in the focus to "infinity" for the shot.  The 10-22mm has a focus distance indicator on the lens... the 10-18 does not.  

[Norm12 · Accepted solution]

Thanks everyone, I appreciate it. I kind of figured the filter question would get answered the way it did and I will wait and see how users like the new lens when it becomes available. I am just a hobbyist as to taking pictures so I do not want to get a lot of money tied up into cameras and lens so I want to be able to take the best pictures I can with the equipment I have. I'm hoping for positive reviews to the 10/18 as it will save me half the cost of the other lens. Thanks again!