VaricamLT: Lightweight zooms

Milano,

You should be able to see the aperture diaphragm moving when you open and close the iris. Is it getting stuck between 2.2 and 2.9? If you're seeing a smooth open and close, then I suspect there's nothing wrong with the iris. Also check that there isn't additional movement of the ring beyond the movement of the diaphragm. Hopefully that makes sense.

As for the cleaning, I'd expect you'll have to do some on a used lens. I'd personally try to negotiate with the seller to handle some of the cleaning fee. But when someone says a lens is clean, all I assume is that they've personally looked it over. Not sent it in for service.

Also it looks like you have to really go beyond ordinary shooting situations to really see the flaws. So I personally might live with it for a while until I felt the lens needed other servicing.

You might want to send it to a lens shop for inspection. If you've purchased through a reputable 3rd party they should be ok with a professional's opinion as to the state of the lens.

In short a little bit of cleaning might be expected for a used purchase. Definitely shouldn't have mechanical damage!!!
 
I was puzzled with the aperture issue since I had checked if the aperture diaphragm was moving, which it did. So I tested the lens again under other lighting conditions and then the exposure changed immediately although it was a subtle change. So I regard it as "solved", that is: My testing wasn't thorough enough the first time. I've informed the store about this and aknowledged that I was wrong.

Regarding the statement of the lens being clean, for me personally it's simple: It is clean or it is not.
It can be more or less dirty, but the defintion of clean is the absence of dirt, isn't it?

The problem for me is that I was promised a clean lens, not a lens that has to be sent to Germany to be cleaned. If I had known that beforehand I would've never bought it. The store first wanted to share the cleaning cost and know seems to have changed their mind and can agree to pay the whole cost, but still these weren't the conditions for me buying the lens. I've already spent too much time on this issue, trying to find a place here in Sweden that can clean it, e-mailing the store back and forth, and so on. I have a business to run and spending this amount of time on an issue I was told wouldn't be there is kind of frustrating. I've found another (new) lens that I want to buy, but I can only do it if I get a refund and can return the lens. The store hasn't answered my request to return the lens (which I still haven't used, just tested for the issues) for two days now. In my opinion that is not very professional.
 
I recently compared the Zeiss LWZ2 15-45mm T2.6 to the Canon CN-E 15.5-47mm T2.8. Here are my conclusions, based on simple tests (I might be wrong in some conclusions). That is, the best thing is to try them out yourself if you have the chance.

Weight and size:
They are very similar. The Zeiss is sligtly lighter and shorter.

Build quality:
The Canon lens has a fantastic build quality. I wish that the zoom and focus ring on the Zeiss felt the same way and that the Zeiss was built like the Canon lens. It just feels good to use the Canon, everything is so smooth.

Features:
The Canon can be adjusted with a screw while the Zeiss needs shims, this is a clear advantage for the Canon lens. It also has a filter thread at the front, which the Zeiss lens doesn't have. On the other hand the Zeiss lens can change mounts easily. The Canon lens has to be sent to Duclos to get it modified, at a cost, but after that it can change mounts more easy than the Zeiss AFAIK.

Breathing:
At the widest bost lenses have almost no breathing. When zoomed in they do breath, but not very much. This is most noticed if you stop down a lot and when everything is more or less in focus. If things are out of focus and you're doing a focus pull that isn't the most extreme, you'll probably won't notice it. The Canon might breathe a little more when zoomed in, but I didn't check for that thoroughly.

Bokeh:
From what I had the time to check it looked pretty similar.

Close focus distance:
They're both good but the Zeiss lens is slightly better there.

Sharpness:
The Canon lens is sharper in the center of the image at 15.5mm but in the corners the sharpness isn't good at all. The Zeiss isn't as sharp but is much more consistent throughout the frame, but it's also much more sharp in the edges when at wide focal lengths than the Canon lens. At 20mm the results are pretty much the same as in 15.5mm. At 24mm the edge sharpness of the Canon improves.

Vignetting:
The Zeiss lens has visible vignetting at T2.8 but is greatly improved at T4. The Canon lens has a lot less vignetting at T2.8 but at T4 the lenses are more similar.

Light:
The Canon lens appears to let in more light at the same T-stop setting. The vignetting of the Zeiss lens gives the image a darker look overall but also when the image is compared in the centre and when stopped down, the Zeiss seems to be slightly darker.

Flaring:
I didn't check for that but my guess is that the Canon has a bit more controlled flaring.

CA:
The Zeiss has slightly more CA from what I could see, but they both seem to be pretty good. I also compared it to a Sony CineAlta 35mm T2 and they're all quite similar from what I could see in that particular situation.

Focal length:
This is actually quite interesting. At 15.5mm they're almost identical but the Canon gets a bit more in the frame at the edges (read more under Distortion). At 20mm and up the Canon lens has a more narrow field of view. This means that when set on 45 mm the Canon lens has a more tight image than the Zeiss lens, which means that already at that point it has a wider zoom range than the Zeiss lens.

Colour and contrast:
This was a big surprise, because the colour turned out to be quite similar. The Canon lens is a tad more warm. The Sony CineAlta 35mm T2 that I also compared them with has a much more neutral look. Zeiss claims that the Zeiss LWZ2 15-45mm T2.6 has a similar colour to their other lenses, but I'm not so sure about that. It looks like it could be more warm, at least from what I've seen from the Ultra Primes. Both zooms could be matched very easy.

The Canon has more contrast in some situations while the Zeiss appears to give a more "even" look. I didn't check for this much, it's just an impression. In some instances I would probably not be able to tell which lens was used, if only judging the colour and contrast.

Distortion:
I saved this for last since it turned out to be a big deal. The distortion that the Canon lens has makes it "unusable" in my opinion. The Zeiss lens has some distortion too, of course, but when they are compared the Zeiss lens wins this by far. At the widest, the Canon lens has a very obvious barrel effect. The image is so skewed that it's easily noticed, and this isn't just the edges. Even in the center of the frame things look swollen. This means that it makes faces look more round than they are. It just looks bad, im my opinion. The Zeiss lens looks much more natural.
When zoomed in things change. On the Canon the edges change character and get an obvious pin-cushion distortion while the center still has some barrel distortion, at least up to 24 mm but maybe even further. The Zeiss looks good in the center and has some pin cushion effect in the edges when zoomed in. At 45mm it looks quite good I think, while the Canon can't have lines look straight at all at any focal lengths, as far as I could see. The distorition is so obvious IMO, that I wouldn't use the Canon lens.


At first I had planned to buy the Canon lens and sell the Zeiss lens. The Canon lens is a better lens (or similar) except from edge sharpness and the distortion. I could probably live with the soft edges, but the distortion is just too bad IMO for a lens this expensive. My friend with whom I tested it (he is a great stills photographer) thought it was crap, especially when the price was considered. It was actually quite frustrating, since I really love the build quality of it, it just feels so solid. If there only was less distortion the Canon CN-E 15.5-47mm would've been a great lens. Perhaps Canon should've decreased the focal range and reduced the distortion instead...

I'll see if I can arrange to compare the Zeiss LWZ2 with Angenieux and Arri Alura lightweight wide zooms some time in the future.
 
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Nice comparison, thanks. Confirms my operations, Canon tries to make a nice lens, but does not quite get all of the bits right. They seem to concentrate on the mechanical side, at the expense of the optical quality. In the last 20-years, Canon optical quality seems to have taken a dive, relying on "in camera" correction of optical issues instead of getting it right in the first place.
This is why I do not use or buy Canon lenses. I even removed them from my ENG cameras, and replaced them with Fuji ENG zooms. Zeiss at least gets the optical quality where it needs to be to do the job right.
Cheers
 
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I bought another zoom instead, the LWZ.3 21-100. It arrived today and so far I'm very pleased. The colours seem to match adequately, although I have to make further tests. The LWZ.2 is slightly warmer (more yellow) than the LWZ.3.
Wide open at 21mm the LWZ.3 actually seems to let through more light than the LWZ.2 at 21mm T2.6, but I have to test that further to see if it's correct. There's almost no breathing at 15.5mm on the LWZ.2, the breathing increases slightly when changing the focal length. The LWZ.3 works in an opposite manner. There's almost no breathing at 100mm, but as the focal length is changed to wider, the breathing increases slightly. The LWZ.2 has a slightly wider FOV at 21mm and 45mm than the LWZ.3. The LWZ.3 is a bit longer but feels a bit lighter. _20171204_181404.jpg
 
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