RF24-105/4 performance

Started 3 months ago | Discussions thread
Thomas A Anderson Contributing Member • Posts: 895
Re: RF24-105/4 performance
1

Peak freak wrote:

koenkooi wrote:

Peak freak wrote:

Update: I finally got a chance to do some controlled tests outside. [Tripod, IS off, remote]

In short, the lens seems to suffer from quite strong field curvature coupled with some mild decentering. If focusing at anything less than infinity, edge blurring becomes pronounced. Curiously, the corners hold up well compared to the boarders even though they are often even further behind the plane of focus.

I did several tests at different F/L's. Most tests were focused at about 13m / 40feet which should provide ample DoF at 35mm / f8 but there was consistent blurring on the lefthand side. (A little on the RHS but not enough to be a problem).

One set focused at infinity offered acceptable results.

I have a suspicion that it might be front focusing, exaggerating the problem, but difficult to ascertain because there is so much DoF at f8. I'll do some more tests. [I am aware that mirrorless shouldn't FF, but also aware that they occasionally do].

Did you have a filter on the lens during testing? There have been a few cases on this forum where a UV filter influenced DPAF focussing.

Thanks for this. Yes, a Hoya HD digital UV filter (I think).

I'm suspicious because some images I know I focused at (or near) infinity exhibited the same edge softness as I am getting when focusing at closer distances. Having no distance scale on these new RF lenses doesn't help.

You can display the distance scale on your camera screen.  You can also switch to manual focus and use the MF Focus Assist (or whatever it's called....the little green arrows that light up when you're focused correctly).

The lens has some weird characteristics (that another poster also mentioned). I'm comparing some of my adapted EF16-35/4 lens at 35mm (which has the same filter). It sometimes has some edge softness too, but it is like a predictable, smooth roll off. This is different, with 'blobs' of blurring and sometimes ghosting.

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