Lens Poll.

J A C S wrote:

Great Bustard wrote:

J A C S wrote:

Great Bustard wrote:

Let's say Sigma or Canon were to put out a new set of "slow" primes that, stop-for-stop, were every bit as good as the best out there, if not better, have IS, and were a lot smaller and lighter. Would you buy they at the same price point?

For example, consider the following examples:

• A 35 / 2 IS that was every bit as good as the 35 / 1.4L II stop-for-stop, if not better, had 5 stop IS, and not much larger than the current 35 / 2 IS.
• A 50 / 2 IS that was every bit as good as the Sigma 50 / 1.4A, stop-for-stop, if not better, had 5 stop IS, and halfway between the Canon 50 / 1.4 and Sigma 50 / 1.4A in size/weight.
• An 85 / 2 IS that was every bit as good as the Sigma 85 / 1.4A, stop-for-stop, if not better, had 5 stop IS, and halfway between the 85 / 1.8 and 85 / 1.4A in size/weight.

The only way for this to happen is to take an f/1.4 lens and artificially restrict it to f/2.

I think I have to disagree with you on this. I should start a thread on that in the PST forum.

Just to match the vignetting of an f/1.4 lens at f/2 you pretty much need what is called today an f/1.4 lens. Strong vignetting is responsible for weaker and poorer bokeh; one of the reasons f/1.4 lenses are much better at f/2 than f/2 ones (and not so great in terms of quality of the blur away from the center wide open).

I'll be pleased to learn something new!

https://www.dpreview.com/forums/post/59575854