Points in Focus Photography. Blog. Photography. Guides. Reviews. Focal length is a measure of how strongly a lens bends or focuses light. A lens focal length doesnt care about the sensor behind it at all, its a property of the lens and only the lens. (and trying to find a DSLR Astrophotography Untracked. sharpening or color enhancement. Switch your lens to manual focus and use magnified live mode to focus your lens on a brighter star.
Finally, step down your lens at least one fstop from wide open. be aware that it is limited by the focal length of your lens. With a 50mm lens, 3second exposures are fine May 04, 2017 Hi All, I got a Minolta MD 50mm 3.
5 Macro and the lens is working fine. but I have problem with stabilizing the image. I know I need to go and change the focal length from Image Stabilizing screen, but what focal length shall I use? giving the fact that I'm using it as macro (close to subject) and I'm also using it with 1: 1 converter (I'm not sure if this will change the focal length) Nov 26, 2016 Calculated focal length at MFD Focus Breathing. The focal length equation for my Sigma 1770 calculates an effective focal length of 43mm at 70mm, though I suspect the actual may be closer to 35mm.
DA Aperture at each Focal Length: gnaztee: Pentax SLR Lens Discussion: 11: 01: 12 PM. Style Selector Is the Pentax DA 35mm F2. 4 AL a good choice for street and night photography? before I fully understood how focal length relates to field of view I had my eye on the Pentax DA 55mm F1.
4, which is just about within my budget and is weather sealed. I used the 40mm f2. 8 as my main lens on Pentax cameras for many years, and have Lens Magnification and Depth of Field Calculator Which of my lenses is best suited for macro photography? How much would a lens extension tube improve the situation? Jan 24, 2006 If we suppose this was an f2. 8 lens, and use the equation that depth of focus equals (2)(focal ratio)(diameter of circle of confusion), and choose 30 microns as the typical CoC, then the depth of focus is 0.
2mm. Jun 03, 2009 I find that the 28mm is a very good focal length for the K10D, and that is what stays on my camera most of the time.
The 28mm is just about a perfect normal lens, you just have to figure out if you are ready for manual focus. As usual we're a little surprised to see a 50mm lens projected for an APSC system we find it something of a 'nomans land' focal Pentax manual lens focal length equation between the 'normal' and 'portrait' ranges, but to be fair 50mm lenses seem to be selling well anyway.
The focal length refers to the distance between the sensor and lens aperture, and determines how wide or narrow your angle of view is. Shorter focal lengths provide a wider angle of view, while longer focal lengths give a narrower view angle, allowing you to zoom in on distant objects. Using old, manual focus lenses with a new Pentax DSLR. up vote 1 down vote favorite.
It extends the focal length by factor 1. 7, turning your 50mm into a 85mm. Which, on today's digital Pentax bodies is then effectively a 135mm because of their smaller APSC sensor area, adding another 1. 6x magnification to any classic lens (Note that even