Here is an example: For a 300mm lens, divide 300 by 50 to get 6x magnification.

400x

4x is a common magnification for scanning objectives and, when combined with the magnification power of a 10x eyepiece lens, a 4x scanning objective lens gives a total magnification of 40x.

Most educational-quality microscopes have a 10x (10-power magnification) eyepiece and three objectives of 4x, 10x and 40x to provide magnification levels of 40x, 100x and 400x. Magnification of 400x is the minimum needed for studying cells and cell structure.

This characteristic results in a 1.5x equivalent magnification factor of your lens. A 600mm f/4 AF-S mounted with a Nikon D1h is a 900mm f/4 equivalent lens. That’s huge!

A 70 to 300mm lens a is a telephoto lens that has a zoom function. There is an advantage in using the 70 to 300mm lenses as they offer versatility. Such a lens can be used for daylight telephoto subjects including wildlife, travel, candid and portrait shots due to its wide range of focal length.

Get closer to the action With a 300mm maximum focal length (450mm equivalent on DX-format cameras) it brings even the most distant action closer. It’s an ideal lens for candids, travel and sports photography.

Best lenses for bird photography

1. Canon EF 100-400mm f/4.5-5.6L IS II USM.
2. Canon RF 100-500mm f/4.5-7.1L IS USM.
3. Canon RF 600mm f/11 IS STM.
4. Nikon AF-S 200-500mm f/5.6E ED VR.
5. Nikon 600mm f/4E FL ED VR AF-S.
6. Sony FE 200-600mm f/5.6-6.3 G OSS.
7. Fujifilm XF100-400mm f/4.5-5.6 R LM OIS WR.
8. Sigma 150-600mm f/5-6.3 DG OS HSM | Sport.

The sharpest aperture of your lens, known as the sweet spot, is located two to three f/stops from the widest aperture. Therefore, the sharpest aperture on my 16-35mm f/4 is between f/8 and f/11. A faster lens, such as the 14-24mm f/2.8, has a sweet spot between f/5.6 and f/8.

AI Servo AF mode