14-140 exposure shift during zoom?

Yes, the Panasonic 14-50mm does breathe noticeably when focusing. Of the six lenses I tested, the only ones that do not breathe significantly are the Lumix 14-45mm f3.5-5.6 and the 45-200mm f4-5.6. The Lumix 45-200mm is really quite remarkable. While it's certainly not the highest performance lens in its class, it combines nearly all the most desirable lens features with the fewest objectionable drawbacks.

Here's a link to the series of zooming aperture fluctuation tests of the following lenses:

Olympus 35-100mm f2.0
Olympus 14-54mm f2.8-3.5 II
Panasonic 14-50mm f2.8-3.5
Panasonic 14-45mm f3.5-5.6
Panasonic 45-200mm f4-5.6
Olympus 50-200mm f2.8-3.5 non-SWD

http://www.dvxuser.com/V6/showthrea...-during-zoom&p=2259656&viewfull=1#post2259656
 
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Barry_Green said:
There is fluctuation during the zoom movement. If you use it as a variable prime, it'll always settle in where you want. But as you travel, it fluctuates.

Nature of the beast, I'm afraid. It's a $700 lens that does a million things automatically; it doesn't appear to do them all perfectly. If you want perfectly stable zoom & iris, you can get the Red Pro 18-85 zoom, but note that that's $10,000. And about 10 pounds.

If this was marketed as an ENG camera, and the 14-140 was marketed as an ENG lens, I'd say they were both pretty mediocre to lousy for that job. But it isn't, and I still say that if you had to do that job with an AF100 (and I would recommend against it) but if you HAD to, the 14-140 is still the best game in town. It's got the zoom range, the OIS, and the autofocus that make it the best substitute for a video camera lens that we can currently get, and it's cheap.

But no, it's not an ENG lens, and you're ideally not going to be doing a lot of zooming during a shot with it. If you absolutely need a low-cost, perfectly-zooming camcorder, the AF100 isn't it, you should be looking at the HMC150, HPX170, HMC40, HMC80, or any other designed-for-ENG camera.
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so if we want to use ANY zooms INSHOT do we need to stick with zoom lenses that have a consistent aperture through the range? i totally hear you that the camera/lenses are not targeted at ENG style shooting... but being restricted to zero zooming inshot is a major headache for me. HA! i am poised and ready to nab an olympus 14-35...
 
lpowell, thanks so much for doing these tests, the panny 14-50 seems tolerable. I would love to see this same test done with the olympus 12-60. Any one who owns that lens care to participate?
Right now i'm mostly relying on my sigma 18-50 2.8 as my documentary handheld lens. The aperture stays constant and focussing is mechanical. The drawbacks are that it's not quite wide enough, No OIS, and the throw on the focus ring is VERY short. But for now it will do.
 
Yes, thank you for the tests, lpowell! Very helpful. The Panasonic 14-50 does seem to handle zooms pretty well; I wonder if it does as well on the AF100? (Anyone tried it?) Could be that the difference between it and the 14-140 is in differing lens mechanics, or maybe it's just the particular camera and firmware you have operating playing well together?

And I second tacotim; I'd love to see someone post some zoom tests with the Oly 12-60mm (preferably on the AF100)!
 
Ljung, I can't speak for the 14-50, but i have the 14-140 and it exhibits the same behavior on both my af100 and my GH2
 
ozman said:
so if we want to use ANY zooms INSHOT do we need to stick with zoom lenses that have a consistent aperture through the range?
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Well... see, here's the thing -- you're talking about using still-camera lenses. They were never designed for zooming in-shot! That's something that you just don't do on a still camera.

Some may work, but I'm not at all surprised that some/many/most don't.

If you want a lens that's designed to do zooms in-shot, then you're looking at mainly cinema zooms, and those won't have auto-anything and will usually cost quite a bit more.

Look at lpowell's tests for some lenses that look like they might work out.
 
Yes, but if you set it to f5.8 or smaller aperture manually it should not shift exposure from wide to tele. It should remain constant unless there is an auto exposure setting that is messing with it. Is it possible to set a full manual exposure mode so this doesn't occur?
 
razzi, if you must have a lens for zooming in shot now, i can confirm that the sigma 18-50 f2.8 (i have the pentax kmount version) zooms without any exposure fluctuations.
I also have a pentax smcA 35-105 f3.5 that zooms without fluctuating. That one serves as a great tripod interview lens. I'm sure there are others out there.
I am hopeful that sigma or one of the other lens manufacturers that have recently signed on to M43 will see our need for a zooming stabilized lens with consistent aperture.
 
tacotim, what adapter are you using to control the aperture on your k-mount sigma?

Also, I'm curious about the Panasonic 14-50mm now; wondering if it's mechanically impervious to exposure fluctuations the way my Tamron 17-50mm seems to be, or just much, much faster at making corrections to whatever weird stuff is happening with the elements? Is it possible to zoom back and forth really fast and confuse it? Also, exactly how bad is the breathing?
 
On the other hand, the Panasonic 14-50mm is capable of stabilizing this sort of handheld shot on a Panasonic G2:


There's no disputing the fact, however, that focusing is this lens' weak area. For this video, I got an initial focus-lock on the front of the bridge in AFS mode and then switched to manual focus just before hitting the record button. With the overcast daylight, I had enough stopped-down DOF to grab the shot without needing to pull focus.
 
Wow - this is all getting really disheartening (using a zoom lens as a variable prime for the AF-100).

It seems like just about every zoom has exposure shift - so you can't zoom in a shot (I'm not even talking run-and-gun ENG-type use - just the occasional desire to maybe zoom a shot for digital filmmaking).

On top of it, it seems just about every zoom (including those that DON'T have the exposure shift) have breathing problems when focusing. You can't even properly pull focus or rack focus for digital filmmaking.

And no OIS support on most zooms (for now).

Sheesh.

I had my eye on the Olympus 12-60mm f/2.8-4 ...but now I don't know what I should do.
 
Zooming with lenses

Zooming with lenses

What a great post. I just bought a 14-42 3.5-5.6 Panasonic. Brought down quickly by doing my own little exposure test with the lens. Yes, it is awful, a complete exposure shift even when you are set to 5.6. So, really all these cheap lenses are just that, cheap.

I'm back to where I started - a Fotodiox adapter for 39 bucks EOS to m4/3. And I just use my 24-105 Canon EOS, and my 17-40 Canon EOS. At f4 they are not significantly slower, and if you want, Canon makes f2.8 lenses. Are they cinema or ENG zooms? No, but the zooms are smooth and if you can live with the focus breathing you can pull off a shot.

There is also this option: a rather pricey adapter to put a 2/3" ENG lens (less than 2k on Ebay these days) from Abel Cine Tech:
http://blog.abelcine.com/2011/02/11/using-23-lenses-on-the-panasonic-af100/

thanks for all the great posts.
 
I have ranted long and hard with my own opinion about this camera and the use of "still lenses" on it. Especially zooms.

Apart from cine style zoom lens...you will not find a current zoom lens (stills style) that you will ever be really happy with as a zoom lens ( compared to the cine ones which are designed for the function in every respect).

Still zoom lenses as variable primes...different story.

Nikkor 17-35mm f2.8 constant ( manual aperture) ..I highly recommend. Then I run out of recommendations based on my own rules. ( I will not use a lens on my camera with OIS, AF, variable aperture across range,... then brand and quality factors). I have looked around a lot I might add.

Prime lenses...easy. Thats what a production camera uses.
 
That Nikkor 17-35mm f/2.8 seems like a really nice lens.

No OIS, no AF or push-autofocus - but none of these things are on cine lenses anyway - so it forces true old-school technique.

How is it w.r.t. breathing?

Also - Is there a mount adapter you recommend? (Voigtlander?)

Thx,

Steve
 
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