And don’t waste your money on one of those mutated fisheye adapter gadgets that screw into the front of another lens-they are sheer disappointment. Do yourself a favor and visit an actual camera shop to make your purchase so that you can preview the effects before summoning MasterCard. Those that fit on DSLRs render different results on full-frame DSLRs as compared to crop-frame APS-C format models. Many fisheyes work on mirrorless cameras only. Focus is easy, however, because the depth of field stretches from here well into next month. Inexpensive circular fisheye lenses are manual focus and Aperture Priority (or Manual) exposure only. I’m trying to get their input for the review but so far they’ve resisted my efforts to communicate with them.īeyond that, all of the predictable caveats apply. And if anyone knows how to contact Meike’s Marketing, PR or Sales Dept in the US, please let me know. Spoiler Alert: save yourself some time and just order the lens now.
In the next few weeks I’ll be posting a full review of this lens. Both are cool, but the circular is more fun, in my book, and the images are instantly recognizable as being fishy.Įvery image in this piece was shot with a Fujifilm X-E1 and a Meike 6.5mm f/2 Circular Fisheye. They are used in both stills photography and video recording, and you can even get adapters for some smartphones that allow you to simulate the dramatic ultra-wide effect. The circular fisheye, which we’re covering here, instead turns 180 degrees of reality into an amazing circle, leaving a black border and negative space in the unexposed area of the frame. A fisheye lens is an extreme wide-angle optic that allows you to capture a distinctive and distorted view of the world.
The full-frame type, as the label suggests, fills the entire frame with wonderfully warped, perspective-bending wideangleness. Unless you plan on close focusing (closer than 0.5m), setting the focus to between 1m and infinity, aperture to f/8, you can snap away all day long without having to touch the focus, or the aperture ring, as EVERYTHING is in focus from 0. This for me is the best bit about using a fisheye like this. There are two types of fisheyes, not including those found on actual fish. Focus distances on the lens include 0.3m 1m, followed by infinity. Here’s what extensive hands-on practice has taught me so far. Products like the Meike 6.5mm f/2 ($129) and 7artisans Photoelectric 7.5mm f/2.8 ($139) plus offerings from Bauer, Rokinon, Opteka, Samyang, Venus and some camera manufacturers are very affordable, exciting and-by and large-pretty damn sharp. With the camera in a fixed position, take several pictures showing the checkerboard in different positions, covering a good part of the field of view.Fisheye lenses abound, and many are priced under $199.VPI provides in samples' assets directory one 10x7 checkerboard file that can be used, named checkerboard_10x7.pdf. Print a checkerboard pattern on a piece of paper.
To create a set of calibration images for a given lens, do the following:
They are found in /opt/nvidia/vpi2/samples/assets/fisheye directory. VPI samples include a set of input images that can be used. The more images, the more accurate the calibration will be, but typically 10 to 15 images suffice. There is no single fisheye projection, but instead there are a class of projection transformation all referred to as fisheye by various lens manufacturers, with names like equisolid angle. Lens calibration uses a set of images taken by the same camera/lens, each one showing a checkerboard pattern in a different position, so that taken collectively, the checkerboard appears in almost entire field of view. A circular fisheye can be made full frame if you use it with a smaller sensor/film size (and vice versa), or by zooming a fisheye adaptor on a zoom lens. The mapping used for distortion correction is VPI_FISHEYE_EQUIDISTANT, which maps straight lines in the scene to straight lines in the corrected image. Then it uses Remap and the calibration data to correct fisheye lens distortion of these images and save the result to disk. This sample application performs a fisheye lens calibration using input images taken with the same camera/lens.