AquaTech Soft Cap for Canon 600mm f4 IS USM

Highly recommended - much easier to handle (and much cheaper) than the originals canon cover

Do you have ascn-6 for Nikon？？？

I use this cap with the Canon 600mm v2. There aren't many options for this type of lens cap and this one works well enough but is a bit overpriced. My cap doesn't contact the lens and does bow out in the center to prevent contact. With the cap pressed in all the way I'm able to stand the lens on end and still not have contact with the glass.The logo in the center is raised but is not colored as in the product photo. I consider that a positive factor.

I could go either way between 2 or 3 stars. This is not exactly what I expected. I have the one of the 300 2.8, and I like it much better. You can would think they would be the same. They almost are. The one in the 300 2.8 version ends up bowing away from the lens with an air pocket of protection. This one fits very close to the lens in in the center. It doesn't touch the lens unless it gets pushed on very lightly. The other one has resistance. In other words, this does not protect the Canon 600 f4 very well at all. I am going to keep it. But I am going to use it in conjunction with another method of protection for the front element. This is an extremely expensive piece of rubber that doesn't do what it should, very well. It keeps dust off the lens, that is about it.

Received this product today, fits perfect and will not fall off lens, good protection.But for me I wish they would made the material lighter.