Lensbaby Burnside 35mm F2.8
General Image Quality
On the following pages we will look in detail at every measurable performance parameter, but for the moment we will consider those subjective elements that can make or break an image.
Field of View
35mm is a common focal length. What is unique about the Burnside is that Petzval lenses usually use a much longer focal length, making this lens something of a rarity.
On full frame, this focal length is well suited for quite a variety of purposes. It can serve for architecture, full- or half-body portraits, candids and group pictures, and many other purposes. On APS-C the field of view is of course narrower, bringing it closer to a “normal lens” (35mm’s field of view translates to an equivalent 52mm). The lens's relatively close focusing capabilities (up to 15 cm) increase its possibilities.
Note that, in part by design, the lens exhibits strong field curvature, which will significantly impact the sharpness in the corners. The Burnside should not be used for landscapes with wider apertures.
Color and Contrast
Petzval lenses are supposed to produce a stronger contrast than most modern lenses, with vivid colors.
The lens' rendering is not overdone, however. Colors are bright and well saturated, but remain natural and realistic.
Darker areas and shadows remain a good level of detail, with adequate if not exceptional transitions.
Metering and Exposure
With a fully manual lens, exposure is dependent on the user. The Burnside does not use stop-down metering and closing the aperture is immediately visible in the viewfinder.
Users must be aware that closing the secondary aperture will have some impact on the total exposure. Vignetting will increase, of course, but since the secondary iris is not placed at the lens’ aperture stop, the center will also darken when this iris is closed. It is advisable to use M mode and the green button after setting the main and secondary apertures.
Starbursts are absent at wider apertures, but present at smaller ones, like F8 below. Their shape is not usual: closer inspection shows that they are comprised of multiple lines diverging, creating a diffuse effect.
Lens Corrections and EXIF Data
There is absolutely no in-camera lens correction. EXIF information is still recorded, apart from the aperture.
On-Board Flash Usage
The K-1 does not have an on-board flash. When testing on a K-3 (an APS-C DSLR), we did not observe any shadow caused by the flash. This is not surprising considering the small size of the lens.
The Lensbaby Burnside takes some time to master. It is easy enough to set it at F8, open the secondary iris, and shoot away. However, that’s not where the distinctive nature of the lens is used to its fullest. It is also not advisable to simply shoot always at F2.8 with the iris closed. Different settings will work best in different situations, and each photographer will have preferences that will be discovered only through experimentation.
What is sure is that, when used properly and thoughtfully, the Burnside has the ability to add interest to scenes which might otherwise be bland and lacking. Taking the time to master the lens, and taking the time to set the shot, will deliver rewarding results.
In the next sections we will look at the optical performances of the Lensbaby Burnside 35.