FS7: Bad vignetting of my FS7 kit lens when on FF sensor

moldcad

moldcad

Veteran
Hi guys;
I have a question for you: has anyone owning the FS7 kit lens (SELP 28-135mm F4 OSS) tried it on a FF-sensor camera? Because I did - over a year into my owning of the FS7 kit and happily shooting with this lens in S35mm mode, I bought myself the A7Rii camera - hoping that this FF lens would finally get proper use on a FF sensor. And indeed - with actual (in 35mm terms) 28mm FoV at the wide end - it's now giving me many more opportunities. But unfortunately, I discovered something I'd never even know using this lens on the FS7 only: at the wide end, and fully open at F4.0 - it vignettes awfully in the upper left corner, so any bright sky takes are a no-no... Just wanted to ask you guys whether this is a "feature", or is my unit faulty? I almost suspect Sony were selecting out the worse lenses during quality inspection and sold them as FS7's kit lenses, hoping they'd only be used with APS-C (S35mm) crop and thus the vignetting would escape unnoticed... :( Please share your thoughts before I send it to Prime Support for repair... TIA,

Piotr
 
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My guess is that such a lens is engineered to be at the absolute edge of acceptable performance.

(hense sony's ability to deliver zoom lenses, at 1/2 the price of everyone else)

Use it with sonys lens correction in non log and this 'problem' probably becomes 'acceptable'

Of course your expecation for this lens to match a leica or cooke prime is not reasonable.

I doubt that it is broken.
 
Hmm... In this context, the FS7 mkII kit lens' price being almost double that of the 28-135mm in spite of it being just an APS-C lens, is even more interesting... would it be justified?

Piotr
 
I dont know sir, Ive always had a simple mantra that one uses zooms when running around and primes on architecture and landscape work. Im not a tech nerd.
 
Thanks Sam, sir :)

Piotr

PS. Yes I'm probably a tech nerd, but being and engineer probably this is natural. But I really do use my equipment to take actual video - believe me (and stills too, ever since I added the A7Rii to my arsenal) :)

PPS. This kit lens I have - being a zoom, i.e. a run&gun weapon - actually performs perfectly in A7Rii multiple AF modes (on the FS7, the AF is hardly usable at all).
 
moldcad said:
PS. Yes I'm probably a tech nerd, but being and engineer probably this is natural. But I really do use my equipment to take actual video - believe me (and stills too, ever since I added the A7Rii to my arsenal) :)
Click to expand...

Interested to see some of your work Piotr. Don't worry I'm not a hugely critical viewer - just always interested to see all the diverse videos and films produced by the contributors to this community of ours!

Cheers,

jason
 
Thanks Jason - unfortunately, my finalized work so far has only been the classical music DVDs and BDs I produced for the company called Castello GT (all mentioned here: http://www.castellogt.pl/plyty-wydane), and I'm not entitled to publish this materials as it's being sold in the form of the DVDs. BTW, haven't made any of them with my current equipment yet - for all those already published I delivered footage off my EX1. And with my current gear I only have some bits and pieces, graded for HDR and for my own private viewing only :). But if I decide any of those has already left the stage of testing and experimentation, I'll most certainly upload it and post the links here for the community to critically view and advise. Cheers

Piotr
 
Well actually I used to shoot kodachrome 64 on my old nikkors and it looked better than an alexa/f65 - anything - so my mantra is 'it is not the glass ruining your pics' - Of course Ive had some horrors - various consumer nikon zooms, and the like that were clearly smear factories. But of course a nikon prime 20 manual is actually quite costly with no electrics, or zoom so one would expect not to worry about it. If the sony zooms dont actually smear the image then Id see that as a victory for them :)

S
 
When you say there's vignetting in one corner (and I assume not in the other three??) that says to me that there's something off -- or misaligned. At one point I used a 28-135 on my original A7s with no vignetting issues that I can recall (or that the producer or editor mentioned). I don't own that lens, but I'd say that there's definitely something out of spec in the lens or the mount if you're getting uneven vignetting.
Does the lens otherwise track properly when on your A7r?
 
broughtonfilm said:
Comment deleted (oh duh ! )
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Haha - I managed to notice your comment before it was deleted - of course there are no ND filters on the A7Rii, so I'm using external high quality glass in Redrock micro MatteBox :) But nothing is obstructing the light path.

Piotr
 
Off centre is indeed evidence for the lens being wonk.

You sure your MBox is not fouling - maybe stop to F22 and point at the sky ?
 
Sam - with or without the Mbox, at F8 and up the vignetting is gone. Like I said: it's the worst at 28mm F4.0, the longer zoom and the smaller aperture it gradually vanishes. And I tested it w/o the Mbox, as well (of course).

Piotr
 
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