nom de produit：SHARPSTAR-Askar ACL200
Paramètres du produit：
Product parameters:
Lens focal length: 200mm
Frame size: Full frame
Lens structure: 3 sets of 6 pieces
Aperture blade: 10 pieces
Minimum aperture: 22
Nearest focusing distance: approximately 3m
Focusing method: manual focusing
Focusing type: coarse motion and micro motion
Inching distance: 1mm
Filter diameter: 82mm
Maximum diameter and length: Φ 100x195mm
Weight: 1.8KG
Focusing:
This lens adopts two manual focusing modes, thick and thin, which can make precise adjustments to the sky stars for easy focus.
1. Fine focusing:
After connecting the camera, rotate the coarse focusing ring to roughly focus the lens on the object to be photographed, allowing for quick and convenient focusing during ground scenery photography.
2. Thickness focusing:
On the basis of coarse focusing, rotating the focusing ring can perform fine focusing stroke control on the shooting object, which is particularly effective in starry sky photography. It is usually combined with the screen magnification display function that most cameras currently have, which can accurately locate and locate the focus position, making the star point present the most delicate and clear image effect.
Aperture effect:
Although this lens is a professional astronomical camera lens, the effect of capturing scenery is also considered in the design. Therefore, an aperture component that is rarely seen in astronomical telescopes is added, allowing the F4-F22 aperture range to be freely adjusted when shooting scenery, facilitating correct exposure and controlling depth of field.
1. The world's first 200mm focal length astronomical professional photography camera lens adopts the appearance and structure of the camera lens, integrated design, compact, lightweight, and simple to use;
2. The uncompromising optical design for star point optimization eliminates the need for complex accessory equipment to capture the starry sky, making it no different from a typical camera lens in terms of usage;
3. Excellent color difference control, no need to worry about general camera lenses and astronomical telescopes
The resulting color difference halo causes blurry imaging;
4. Full frame screen with built-in flat field function, effectively correcting peripheral star point coma and distortion;
For astronomical photography, F/4 belongs to the fast focal ratio, which effectively shortens the exposure time and reduces the burden of long-term tracking accuracy on the equatorial instrument;
6. For starry sky photography, two sets of focusing modes are adopted: mode one is coarse focusing, and mode two is 1mm fine focusing, making focusing no longer a problem;
7. Special optical optimization design has been made for scenery photography and an F/4-F/22 aperture design has been added, making it possible to use it for ground scenery photography while shooting the starry sky. It kills two birds with one stone and has a minimum focusing distance of 3 meters.