Why aren't there any primes with IS?

Seriously? Why not?

I want a f/1.4 prime with IS, gosh darnit.

Pair that with a 50D with ISO up to 12800, who would need a tripod?

EDIT: haha, wait. I meant short focal length primes.

Canon EF 300mm f/4 USM L IS

If you "need" IS on a 1.4 lens at 50mm then you have a serious issue of some kind.

KarlosDaJackal wrote in post #6363024
If you "need" IS on a 1.4 lens at 50mm then you have a serious issue of some kind.

Serious issue like not enough light? You're damned right.

One explanation might be that primes are all about optical excellence. The inclusion of an extra, moveable, optical element for the IS mechanism runs contrary to that and represents an optical compromise that the designers and many prime users don't want. Due to the greater effects of camera shake at the longer focal lengths the inclusion of IS is becomes a "necessary evil".

Cadwell wrote in post #6363042
One explanation might be that primes are all about optical excellence. The inclusion of an extra, moveable, optical element for the IS mechanism runs contrary to that and represents an optical compromise that the designers and many prime users don't want. Due to the greater effects of camera shake at the longer focal lengths the inclusion of IS is becomes a "necessary evil".

Isn't the 300mm f/2.8 IS considered one of the sharpest lenses Canon makes though?

El Duderino wrote in post #6363052
Isn't the 300mm f/2.8 IS considered one of the sharpest lenses Canon makes though?

Some people will tell you that, some people will also tell you that the older non-IS was sharper. There are many opinions.

However, you have to compare apples with apples. The optical design and the design challenges of a 300mm f/2.8 prime are very different from a 50mm f/1.4 prime. What works well in one doesn't necesarily work well in another. Just because including an IS element in a 300mm doesn't cause "much harm" doesn't mean that doing the same thing in a 50mm or a 35mm will work in the same way.

Cadwell wrote in post #6363071
Some people will tell you that, some people will also tell you that the older non-IS was sharper. There are many opinions.

However, you have to compare apples with apples. The optical design and the design challenges of a 300mm f/2.8 prime are very different from a 50mm f/1.4 prime. What works well in one doesn't necesarily work well in another. Just because including an IS element in a 300mm doesn't cause "much harm" doesn't mean that doing the same thing in a 50mm or a 35mm will work in the same way.

Thanks for the explanation, it makes sense.

Still...a guy can dream can't he?

I don't know why they don't, but I'm pretty sure it would cost a sweet bundle of cash if they did add IS.

What about a 300mm F4 I am sure even at F4 you would need IS

I would also think that there's very little space in short primes to mount the required extra lens group.

Bob

They all have it as an optional extra. It's called a tripod.

This is where the in body IS is useful. I've used a Sony alpha with my Minolta 50 1.4 AF prime and I was impressed at the IS for the shorter focal length. Though I still prefer Canon.

El Duderino wrote in post #6363039
Serious issue like not enough light? You're damned right.

Well if you go to the trouble of getting a 1.4 lens and an ISO12800 camera and you still don't have "enough light", i think a tripod would serve you much better than 4 stop IS.

Canon Bob wrote in post #6363107
I would also think that there's very little space in short primes to mount the required extra lens group.

Why would the space in a 50 F/1.4 be tighter than in a 17-55 or 17-70 ?
The answer seems to lie in the simplicity of short primes (good quality at low cost) which would go down the drain if IS in introduced. Adding 4 or 5 IS lenses to a 13 lens construction seems to hurt less than adding it to a 6 lens construction.

KarlosDaJackal wrote in post #6363024
Canon EF 300mm f/4 USM L IS

If you "need" IS on a 1.4 lens at 50mm then you have a serious issue of some kind.

maybe he is an amputee who sold his fake leg to buy the lens and has an inner ear problem...