15mm limited vs 18-135mm@18mm

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left eye
left eye Senior Member • Posts: 2,551
15mm limited vs 18-135mm@18mm

I always knew my 15mm had soft sides and corners - having compared it with my 17-70mm many years ago (that lens now given away). The 17-70 was super sharp right into the corners, optically at 17mm it could have been a prime, the longer end was another story.

Anyway, how good, or bad, is the 18-135mm at it's wide end? - when compared to the 15mm.

I shot both lenses with a sequence of AF tune values, then picked the sharpest in the centre and as far out to the sides as possible. The more I critically shoot with the 15mm the more I realise it is de-centred, with less than good performance on the left. It's the original green ring version, I could send it in but either it'd be sent back saying it's within spec or it'd end up softer on the right etc (I doubt the sides/corners of the 15mm are ever perfect). Focused on far distance, the left side is v.sharp in the foreground.

Overall the 15mm is sharper than the zoom except on the left side - where the zoom pulls ahead (I've marked where the 15mm loses out).

A good result for both lenses I think (de-centring aside).

Focused on the central tree, far horizon. From raw, same ACR settings except for white balance adjustment, full-res examples...

15mm @f6.3

18-135mm @18mm f6.3

GH5 PL12-60mm @12mm f5.6

Thought I'd throw this in, the camera I use mainly for video.

Turns out the GH5 PL12-60mm is much sharper across the frame though tonally not as rich. I'm not keen on the mirrorless experience but the lenses, including the zooms, do seem to be reliably sharp (and never required AF tuning). Much prefer the KP experience, just wish the lenses were a notch up in performance especially the sides. Anyway still can't stop using the KP!

I've now got the AF tune values for all my lenses, so will now end testing - and use them as intended.

The left side of the 15mm will now be bugging me though!

 left eye's gear list:left eye's gear list
Fujifilm X100V Olympus E-300 Fujifilm GFX 50S Panasonic GH5 Pentax KP +11 more
Panasonic GH5 Pentax KP
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