Friday, July 16, 2010

The Superlative Nikon 50mm f/1.4D AF

Back in 2008, I sold off my trusty 50mm f/1.8D AF prime lens, with the idea that I will upgrade to the faster version of the lens. I even placed the order for it on Amazon. For some reason, Amazon had difficulty in fulfilling the order and kept postponing the delivery. I got fed up and cancelled the order and got the 105mm VR macro lens instead.

It was always in my schedule to eventually get the f/1.4 lens, and when Nikon introduced their AF-S version of the 50mm f/1.4, I thought that is the lens I should go for - but the steep price of $440 kept me at bay.

So when I saw an ad for a used 50mm f/1.4 for around $200, I was really really tempted even though I was not sure whether I could afford it. The decision became much easier when my wife urged me to go ahead and pick it up. All photographers should have a wife like mine.

The f/1.4 lens is 2/3rd stops brighter than the f/1.8 counterpart (i.e. 66% brighter). That makes a big difference when it comes to shooting in low-light situations.

The lens can be shot wide open without any worries (i.e. images appear sharp even when the lens is fully opened at f/1.4) unlike some lenses that need to be stopped down by a stop or two to get ideal results.

This picture of my daughter Erika was taken at f/1.4.

BTW, it is a ritual of mine to first take a picture of Erika with any new lens that I purchase.

The f/1.4 also makes it possible to completely blur out the background because of its extremely shallow DOF (depth-of-field). This is easy to see in the picture above. Erika was standing in a mall when I took the picture - but the whole background is completely blurred out.

The shallow DOF makes it very tricky to get the right focus. Even a slight mistake can render the picture out-of-focus so nailing the focus is extremely important when shooting wide open with this lens.

This picture really demonstrates the wafer-thin DOF of this lens. In this picture (shot wide open at f/1.4), just 2 or 3 lines of text are in focus, while the rest of the book (both front and rear) are out of focus. This can best be demonstrated by a 100% crop of the above image.

The area of focus is just a few millimeters. Imagine if you were shooting a portrait with this lens, it would be extremely important to get the camera to focus on the eyes of the model to ensure that the portrait appears sharp. Of course, you must keep in mind that the depth-of-field is also determined by the distance to the subject. Closer the subject (as in the case of Erika above), nailing the focus is paramount. However, when the subject moves further away, the depth-of-field increases. This means that if you are shooting a photo of a person who is 10 meters away, then focusing on any part of the body will be just fine.

Traditionally, on the film cameras, 50mm was considered the "normal" lens because the area of coverage provided by a 50mm is similar to the coverage that we get with our naked eyes. And this principle still applies if you have a FX sensor camera such as a Nikon D700, Nikon D3S, Nikon D3X, etc. However, when you mount this lens on a DX sensor camera such as the D90, D300s, the camera gives you a field-of-view of 75mm because these sensors have a crop factor of 1.5 (so 50mm x 1.5 = 75mm).

Since 75mm is an ideal range for portraits, this becomes an ideal portrait lens when mounted on DX sensor cameras.

Conclusion: If you love low-light photography or portrait photography, you owe it to yourself to invest in a 50mm f/1.4.


Mathai said...

Did you shoot these with the new body? how is it? :)

Cajie said...

Yup. This is shot with the D300. I am experimenting with its low-light performance before I post my impressions on the new body.