jbgeach

I don't get this part. James said optical performance increases due to image compression. So I guess the question is: by how much?

It increases compared to using the lens without the adapter on a crop sensor, it will still be inferior to the lens being used on a Full frame camera. 

I have no idea why we even need large sensors when small sensors can gain 4 stops with an optical reducer completely overcoming any shortcomings with regards to noise and a shallow depth of field

 

The reason is enlargement ratio. There is always a degradation of image quality when enlarging an image. The smaller the sensor, the more times an image must be enlarged to make the display size. Example. MFT has to be enlarged about 10 x to print an 8x10. A Full frame sensor only has to be enlarged about 5 times. This means that the larger sensor will be able to hide more defects than a smaller sensor, because it has been enlarged so much. 

 

My wife as recently watching an American Civil War documentary and commented on how clear the images were for being taken 150 years ago. I explained to her that most of these prints were contact prints, with no enlargement taken on 8"x10" film. 

 

Larger sensors will always have a greater quality to them, however, this prevents the camera from "wasting" all the information that was just thrown away before, by focusing the full frame image onto a crop sensor.

 

A better way to think about this for those who understand anamorphic, is that an anamorphic lens makes you lens wider by compressing a very wide image onto the sensor, so no image is lost (cropped) the allows you to use a longer lens. 

 

Mine is on order

I will bite.

A crop factor is a way of estimating how a picture with a lens from one size sensor will look on the other.

Example. 35mm camera film has been arbitrarily defined as "Full Frame" a sensor with the same size as a film camera. Micro 4/3 has a smaller sensor, this means that a picture taken with a full frame camera and a m4/3 camera will look very different with the m4/3 picture having on the center portion of the photo.

The crop factor tells you what size lens you will need for an equivalent picture. So if using a 50mm lens with a full frame camera, so have a picture look the same from m4/3 you need a 25mm lens. This is a 2x crop factor, because the picture is zoomed in by 2x with the lens.

There are some advantages with smaller sensors including greater depth of field (more of the picture is in focus) and smaller lighter lenses. Larger sensors have better image quality and a 3d quality that is hard to define.

Hope this is somewhat useful, have to run

Jonathan

I love my NEX-7. So many of the issues people complain about just don't matter to my actual photography.
However, I don't shoot wide angle primes.
I do think that once the NEX-7 has met demand, they should put the 5n sensor in a nex-7 body, call it the nex-6 and charge just as much. For me I wouldn't switch, but it seems many others would.
OH, and make a 16-50 2.8 for emount.

Love your review - I had the same reservations about the x-pro-1.

To answer two questions in one:

first you must understand what the f-number really means.
F number is the ratio of the focal length to the diameter of the entrance pupil of the lens. f/D. To have a f number below 1 you must have a larger entrance pupil than focal length.

Note that f - number says nothing about how much light actually goes through the lens. The compensate for this, T stop was developed. T stop is equal to f stop if there is 100% transmittance of light. so if a lens has an f number of 1 and 90% transmittance its T-number is 1.1.

This is a big secret / one of the reason primes look better, the T stop on a prime is much lower than the T-stop of a complicated multi element zoom.

Anyway, this looks like a GREAT lens, really a bang for the buck considering what you get.

Steve huff has been testing it with the m9 and it really looks like a great stills lens as well.

Andrew - I have had better luck using the neutral profile as it. If you go -3 on the sat, contrast and sharp it is just too flat. However, at the default levels, I am very happy