View Full Version : Whats the best E mount lens for depth of field?


Chris Law
January 9th, 2012, 02:43 PM
Hello, ever since my venture into buying the NEX-VG20E camcorder I have being learning new things about lenses that I never had to take into account before.

When I start creating films in the near future im looking to get the best 'bokeh' effect which as far as im aware means having a lens with the highest f.stop possible. But my question am I wrong to think that Sony don't offer any E mount high f.stop lenses?

If my assumption is correct that would make the stock lens the best one for the job, or am I missing something here?

Les Wilson
January 10th, 2012, 08:21 AM
Every lens has depth of field. I assume what you meant was "shallow depth of field" or sDOF as opposed to "great" or "long" depth of field.

Bokeh is a function of several factors that you can manipulate.

Time to read up. Do some searching on the basics of exposure. Here's one to start with: Depth of Field Myth (http://www.bluesky-web.com/dofmyth.htm)

Chris Law
January 10th, 2012, 09:19 AM
Hello, yes I was after a 'shallow' depth of field' look. That link you posted is useful, the only thing that im still confused is how this f.stop thing works.

For instance on this picture the f.stop is f/32 (top-left corner) and f/5 (bottom-right corner)
File:Jonquil flowers merged.jpg - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/File:Jonquil_flowers_merged.jpg)

But as far as im aware of the picture with the f/32 should have the best depth of field since thats the highest after all. What am I getting wrong here?

David Sholle
January 10th, 2012, 10:18 AM
Incorrect use of terminology is getting you confused. First of all, the phrase best depth of field is somewhat ambiguous, and it seems that you are confusing best depth of field with shallow depth of field.

One of the reasons that people choose large format sensor camcorders (or digital cameras) is because it is possible to achieve shallow depth of field, sDOF. In a sDOF image, the object of interest will be in focus and the background (and potentially foreground) will be out of focus. The term bokeh refers to how a lens makes those out of focus parts of the image look. This is affected by the design of the lens and by the shape of the iris in the lens. Some lenses are said to have very pleasing bokeh.

Another problem with the terminology here is the use of high f number. Some take that to mean f/32 while some take that to mean f/2.8. Assuming you want to achieve sDOF, an f/2.8 lens would do that, while an f/32 lens will not achieve that effect. Some refer to an f/2.8 lens as a "fast" lens, as it lets in more light, and in photography, you can take a shorter exposure with it than with an f/32 lens.

The wikipedia link you refer to perfectly illustrates the relationship that sDOF has to f number. The f/5 lens is a faster lens, or a lens with a wider open aperture compared to an f/32 lens, and the picture clearly demonstrates that the f/5 lens has a shallower depth of field compared to an f/32 lens.

Back to your original question - The Sony E lens line is slowly growing, and with the popularity of the NEX camcorders and digital cameras, it should hopefully have more lenses available in the future. Two different E series f/1.8 lenses are available now (or very soon), one a 50 mm and one a 24 mm. These can achieve sDOF if used wide open, that is, set to f/1.8. Please note that both lenses can be stopped down to f/22, which means that the iris in them closes down and lets in less light, but achieves deeper DOF (the opposite of sDOF). The fastest lenses, such as these f/1.8 lenses, will almost certainly be prime lenses, that is, lenses of fixed focal length. Zoom lenses will usually start at f/3.5 or so, and in some cases at f/2.8.

Right now Canon and Nikon (for DSLRs), and to a lesser extent micro 4/3 (for mirrorless cameras) have a wider variety of lenses available than does the Sony E mount. But hopefully the E mount will keep increasing in popularity, as mirrorless system cameras (as opposed to DSLRs) continue to increase in popularity.

Chris Law
January 10th, 2012, 01:44 PM
Thanks for your help, shallow dof makes a lot more sense to me now. I was just wondering since Sony and Ziess both sell f1.8 E mount lenses is their any real difference in the recording quality from Ziess, apart from the Ziess lens being a wider angle. I would be looking to get the best shallow dof look and if the ziess did offer a lot better picture I guess it would be worth the extra money.

Jean-Philippe Archibald
January 10th, 2012, 02:11 PM
The zeiss one might be marginally sharper, and will probably exhibit a better build quality, perhaps better control over CA and other optical caracteristics. But for video work, both lenses should produce perfectly fine results. The obvious difference between these two lenses is definitly the angle of view.

You must decide if you need a wide lens or a normal lens.

David Sholle
January 10th, 2012, 03:59 PM
The following site does technical reviews/test of lenses, and you might find it useful:

Camera lens tests, user reviews, camera accessory reviews - SLRgear.com! (http://www.slrgear.com/reviews/index.php)

Douglas Grillo
January 10th, 2012, 10:35 PM
Maybe the 50mm f1.8 will be the best all around lens for the Nex,nice aperture, Optical stabilization, autofocus.. waiting to arrive.

Glen Vandermolen
January 10th, 2012, 11:15 PM
I'd recommend getting an A-mount adapter, there's a lot of lenses for alpha cameras.

Les Wilson
January 11th, 2012, 06:30 AM
...I was just wondering since Sony and Ziess both sell f1.8 E mount lenses is their any real difference in the recording quality from Ziess, apart from the Ziess lens being a wider angle. I would be looking to get the best shallow dof look and if the ziess did offer a lot better picture I guess it would be worth the extra money.

How shallow the depth of field is will be determined by the size of the VG20 sensor, the focal length of the lens and the aperture setting. Therefore, the amount of the image that is in focus and the amount that's blurry will be the same for two lenses with the same focal length and set at the same aperture. So if the amount is the same, which is "best"?

The difference is going to show up in terms of clarity, distortion, chromatic aberration and bokeh. That's what sites like photozone.de and other lens testing sites can tell you. However, if you look at images from the two lenses and don't love the differences, then you won't appreciate what you are getting in the more expensive lens so don't spend the money. Frankly, the Z lens seems like overkill for a low end camera like the VG20 and for someone just starting to learn. There's plenty more equipment you require besides a camera which will approach the cost of the VG20. Just my two cents

John Jay
January 12th, 2012, 01:23 PM
Opinions will vary, but I consider the bokeh displayed in these model shots to be amongst the best there is

E50 f1.8 OSS的人像试拍 - EVIL论坛 - 色影无忌 - (http://forum.xitek.com/thread-955101-1-6-1.html)

E50/1.8 OSS

ps wait for the images to load its worth it