04-09-2015 09:03 PM - edited 04-09-2015 09:05 PM
The EF-S lenses that I've ever seen stop down to f/16 or f/22. Anything smaller would probably have serious diffraction problems.
04-09-2015 10:26 PM
A bit more detail in the question would help but I'm guessing it is actually asking why there aren't more FAST (large Aperture) EF S lenses. My guess to an answer is Cost to number of Sales. EF lenses work on far more cameras than EF S lenses AND they work on bodies designed for EF S mount. lenses
04-10-2015 08:06 AM
A bit more detail in the question would help but I'm guessing it is actually asking why there aren't more FAST (large Aperture) EF S lenses.
Yeah, maybe he meant to say "low aperture ratio". You're right to give him the benefit of the doubt.
My guess to an answer is Cost to number of Sales. EF lenses work on far more cameras than EF S lenses AND they work on bodies designed for EF S mount. lenses
But they usually don't cover the focal lengths that users of those cameras would prefer. Maybe a salient question is "Why doesn't Sigma still make their highly regarded 50-150mm f/2.8?" I had one of the early versions of that lens, and even it was good enough to be useful on the crop cameras of the time.
04-10-2015 10:33 AM
""Why doesn't Sigma still make their highly regarded 50-150mm f/2.8?""
I love that lens! I sold it along with my last crop body.
I have the 70-200mm version right now and it is every bit as good.
Quite franky I am surprised that Canon does not see the need to do this either. They must think that market will not support the very much greater expense of faster EF-S lenses. Maybe they don't see the need as all the EF fast aperture lenses work on crop bodies. Why dup them?
I believe the EF-S 17-55 f/2.8 IS USM is the fastest EF-S lens? It is nearly $900 bucks.
04-10-2015 12:23 PM - edited 04-10-2015 12:28 PM
Assuming you are looking for large aperture (low number) lenses...
Where EF-S is most imporant is with wide angle focal lengths, where large apertures are much less useful or desirable. Very short (i.e. very wide) focal lengths are considerably easier to handhold... so there's less need for a big aperture to shoot in low light. And very short/wide focal lengths naturally have great depth of field, are far more liklely to be stopped down to smaller apertures than used wide opem, since there's little to no opportunity to isolate subjects with a storngly blurred background.
There are already available large aperture lenses in the standard to telephoto focal lengths, such as EF 24/1.4L, EF 28/1.8, EF 35/1.4L, EF 35/2, EF 50/1.8 II, EF 50/1.4, EF 50/1.2L, EF 85/1.8, EF 85/1.2L etc. In other words, since a crop sensor camera like your 70D can be used with both EF-S and EF lenses, there's little reason to duplicate any of these. An EF-S version of any of these might be a little smaller, but not much. I don't think there would be much savings, either.
A few moderate price EF-S zooms make sense... such as 15-85mm, 17-55/2.8, 18-135, 18-55, 55-250... and one EF-S macro: EF-S 60/2.8. There's also the EF-S 24/2.8 which will serve nicely as a compact "standard" prime.
Perhaps the most important EF-S are 10-22mm, 10-18mm, focal lengths that are basially unavailable in the EF lens line-up. Making ultrawides large aperture would almost certainly degrade image quality, at the same time price, size and weight would be significantly increased.
But, otherwise, why duplicate what's already available and will work on both crop and full frame cameras? IMO Canon has done a very good job with their lens line-up and just keeps improving it year-to-year. I'd rather see them come out with updated versions of some of the good reliable old primes such as the 50/1.4 and 85/1.8... but still EF, definitely not EF-S only. That way I can use them on both my 5DII and 7Ds.
04-10-2015 06:48 PM
04-10-2015 07:14 PM
Thanks all for replying ! but canon makes a 7dm3
Well, no, they don't. Not for a few years yet.
why can't they make a efs with f1.8 f2 and so on without sacrificing angle on view.cuz always have to be calculating the crop factor.
You don't have to calculate the crop factor. The crop factor means nothing. All you have to do is memorize a few useful facts about EF-S lenses. like: "A normal lens is 33mm"; or "A 50mm lens is a mild telephoto"; or "An 11-16mm zoom is wide but not super-wide"; etc. Oh, and "A low aperture ratio means a wide aperture."
04-10-2015 07:52 PM
"The crop factor means nothing."
This is so true. They are simply numbers and are meaningless unless you love comparing everything to a 35mm film camera.
Sigma makes a 18-35mm F1.8 DC HSM A. Fast enough? And it is a EF-S type lens.