Is there a "soft" copy of a 400mm prime?

I'm almost ready to buy my first "L" lens, a 400mm f/5.6. I will use it mainly for bird photography so I guess it's the best choice for me.

My question is, is there a "soft" copy of the 400mm? I've read a lot about "soft" copies of the 100-400mm so I decided to go with the prime. As this is my first L lens, I don't have any means of gauging its sharpness. Also, since I am used to having kit lenses with IS (not to mention that I am a photo newbie), I am anticipating that the first photos I will be taking using this lens will definitely be soft. Therefore, if I do get a "soft" copy of the this lens, it will take some time (way beyond the return date) before I realize it.

I would like to hear feedback from 400mm shooters and their experience, if any, on using different copies of this lens. Are all 400mm created equal, that it doesn't matter if I buy a used or a new one? (The only con I can think of on buying a used one is if indeed there is a "soft" copy.)

Any feedback is greatly appreciated.


Many thanks,
Eric

mine was razor sharp wide open, worked well with a 1.4TC on it too

If you are going to use it for birds, set up a high contrast test target at the distance you are most likely to shoot birds at, mount it on a tripod and take some test shots, good shutter speed as well. Then look at them and see if you are satisfied. Shooting with a long lens does take a bit of getting used to.

Mine is tack sharp, shoot birds at f6.3

Mine is tack sharp wide open. I use it for surf shots from the beach.

Thanks for the replies. All of you got tack sharp primes and I assume have not encountered "soft" ones. I guess that confirms that all primes are created equal.

@Ken & Rocky, thanks for the tips.

Moving from kit lens to 400mm f5.6 will take a while. Do some controlled tests to see how well the lens works. It should be sharp wide open. Mine was sharper at f5.6 than at f8.

There is very little glass in the 400mm 5.6 prime compared to the 100-400mm zoom. I believe this is why there is a variance in copies of the zoom, and more reliability with the prime. I personally bought the prime. Mine is deadly sharp.

I've not heard of any copy variation in the long primes (which is not true of the 100-400), so I reckon you're safe.

Thanks for the affirmation on how sharp this lens is. Having not handled this lens before, I'm afraid that I might cut myself in the process.

Now, I'm really dying to buy one immediately.

Not mine

Owned three when I shot Canon and all perfect ... great with a 1.4x too so long as you are steady, or on a beanbag/tripod/mono. Also owned three 100-400's in my time and not happy with any of them ... all a tad different.

@Rich - Whoaaa!!! Superb hummer shot!

@condyk - Thanks for the info. Having shared your experience on 3 copies each of both the prime and the zoom, that further seals my decision to buy the prime. Hopefully, I can place my order on this beauty early next week. Ahhhhh, super excited already.

Mine was soft on my 40D. With Micro Focus Adjustment on my 7D and 5DII it was much better.

Oh no! So there is a soft copy of this prime. My camera has no micro focus adjustment so I guess this will be a gamble. Anyway, will still push through with the purchase as I presume that there is a slim chance of getting a soft copy of this one over the zoom.

... crossing my fingers....