Optimal Aperture For Foreground Sharpness At Infinity

The technical bits of photography can be a bit tricky. Understanding the effects of different aperture settings comes with lots of experimenting. For example, focusing at infinity sounds fairly straight forward. Essentially everything in the background will be in focus. But depending on the aperture you have set, the items in the foreground may be out of focus. Luckily Robert Seber has posted this helpful chart to his Flickr photostream showing the minimum distance you need to be to get everything sharp and in focus.

Optimal Aperture For Foreground Sharpness At Infinity

To quote Robert on how to read this chart:

Suppose you are using a 20mm lens focused at infinity. Something in the foreground is 12ft away. The point at which 12ft and 20mm intersect is closest to the f/13 line, so f/13 is the aperture to use.

Suppose you are using a 50mm lens focused at infinity. Something in the foreground is 6ft away. No line on the graph is close to this. At this point you need to re-think your shot and move further from the foreground, otherwise it will be intolerably soft. 26ft to the foreground will allow you to use an aperture of f/22.

Suppose you are using a 10mm lens focused at infinity. Something in the foreground is 12ft away. You’re above the f/8 line so f/8 will work just fine.

The basic rule to take away from this is the longer the focal length you use the smaller the aperture you will need to use to get the foreground sharp, or the further you need to move back.

You should also check out Robert’s photos. His macros are really top notch.

Aye Aye, Grasshopper

34-Pound Uber-Telephoto Lens From Sigma

Sigma dropped a doozy of a lens today. The 200-500mm f/2.8 super (dooper?) telephoto boasts being the first lens in the world to maintain such a large aperture throughout the entire zoom range. A dedicated lithium battery pack is required for focusing and zooming operation and an included accessory extender turns this lens into a 400-1000mm f/5.6. Sigma went with a military color palette instead of the typical black. But perhaps the most startling property of this lens is that it weighs 34 pounds! Talk about a back breaker.

Sigma 200-500 f/2.8

Lens name APO 200-500mm F2.8/400-1000m F5.6 EX DG
Focal length 200-500mm
Maximum aperture f/2.8
Minimum aperture f/22
Lens construction 13 groups 17 elements
Angle of view 12.3°-5°
Closest focus distance 150cm / 59.1in
Maximum reproduction ratio 1:4.2
Aperture blades 9
Filter attachment size 77 mm
Focusing Motorized internal focus
Dimensions 236.5mm×726mm (9.3in × 28.6in)
Weight 15,700g (553.7oz)
Supplied accessories • Dedicated hard case
• Strap
• 400-1000mm f/5.6 attachment
• Battery charger BC-21
• Battery pack BP-21

Price? If you have to ask, you can’t afford it. I guess it wasn’t made for people like me who take photos of flag football and spiders in my bathroom. Oh well it’s not like I need another lens.