We conclude that this method of group level scan sampling provides valuable data for characterizing broad diet choice in chimpanzees and other species, but may be of limited use for estimating individual feeding time. However, group level scans tended to overestimate the percentage of observation time spent feeding, particularly for adult males. This validates previous methodology used to identify periods of high energy availability. Monthly means of the percentage of time spent consuming non-fig fruit calculated from group level scan sampling were highly correlated with those from focal sampling. In a 13-month study at Kanyawara, Kibale National Park, Uganda, group level scan sampling provided statistically similar measures of broad diet composition to those produced by focal data, despite considerable seasonal variation. By direct comparison with focal data collected simultaneously on the same population, we assess the validity of this simple group level sampling method for studying chimpanzee (Pan troglodytes schweinfurthii) feeding behaviour. The simplest technique is to record whether at least 1 animal is engaged in the behaviour of interest. An alternative is scan sampling, in which the behaviour of the group is recorded at regular intervals.
FOCAL PRO ALTERNATIVE PRO
Image Pro Plus 6.0 (IPP 6.0, Media Cybernetics Inc, Bethesda, MD. But boasting a bright f/2 maximum aperture for low-light work or for creative background bokeh effects, as well as some top scores for a Canon APS-C wide-angle zoom, the 14-20mm f/2 is an excellent addition to the Tokina line up.Focal sampling is the most accurate method for measuring primate activity budgets but is sometimes impractical. Focal cerebral ischemia reperfusion was induced by middle cerebral artery occlusion. If you want extra scope at the wide end of the zoom, the $599 Tokina 11-20mm f/2.8 alternative is as sharp at mid-apertures and marginally better at f/22, making it a good choice for landscape and architectural photography. The highest-scoring wide-angle zoom we’ve tested on the EOS 760D, it offers good image quality, with better control of chromatic aberration and improved sharpness at the wider aperture settings compared to the cheaper Tokina wide-angle zoom competition. Sitting in Tokina’s PRO lens lineup, the $840 14-20mm f/2 wide-angle zoom is an attractive third-party lens for Canon APS-C shooters, offering good build, internal focus, a clutch focus system, and a maximum f/2 aperture. Measurements: Class-leading transmission and sharpnessĬhromatic aberration field map comparison (13-14mm f/2.8)Ĭonclusion: Excellent choice for low light 0.12x magnification / 28cm minimum focus distance.We ran the Canon EF-S mount version of the Tokina 14-20mm f/2 through the rigors of a DxOMark bench test to see how it performs. Optical construction utilizes 13 elements in 11 groups, including two super-low dispersion elements located at the back of the lens to help correct aberrations such as ghosting and flare. Home audio Casques Car audio Pro audio Cahiers de tendance. By continuing to browse our website, you accept the use of these cookies.
FOCAL PRO ALTERNATIVE MANUAL
Tokina’s unique “One Touch Focus Clutch” mechanism also allows photographers to quickly disengage the autofocus motor and switch to manual focus, by simply sliding the focus ring forward on the barrel of the lens. The Focal website uses cookies to improve your navigation on the site, for statistical, audience measurement, advertising and personalisation purposes. The fixed f/2 maximum aperture lends itself to low light and to creative bokeh effects, and the lens’s internal focus system facilitates easier use of screw-on filters via the 82mm filter thread. Sitting in Tokina’s PRO range of high-grade optics, the $840 lens features an equivalent 22-32mm focal length in 35mm terms, making it ideal for landscape and architectural photography, as well as for shooting in restricted spaces. Focal makes products in six categories: 1) high-fidelity speakers, 2) home cinema, 3) multimedia and wireless, 4) headphones, 5) monitoring and pro studio, and 6) custom and public address. Focalboard is an open source project that is being updated continuously. All Focal products are engineered in France only a few lower-priced multimedia models and headphones are assembled in the Far East. They have a very well-balanced sound profile and a more stable fit, but they aren't quite as well-built. This guide is an overview of the basic features to get you started. The Tokina AT-X 14-20mm PRO f/2 (Tokina 14-20mm f/2) is a third-party wide-angle zoom lens for Nikon and Canon APS-C DSLRs. Sennheiser HD 560S: The Sennheiser HD 560S are open-back headphones that represent a viable alternative to the Philips Fidelio X2HR.