programming4us
programming4us
CAMERA

2014 Macro Lenses Group Test (Part 4) - Sigma 50mm f/2.8 EX DG Macro

- How To Install Windows Server 2012 On VirtualBox
- How To Bypass Torrent Connection Blocking By Your ISP
- How To Install Actual Facebook App On Kindle Fire
9/20/2014 11:18:51 AM
Don’t expect to get everything sharp when using a macro lens!

When you’re shooting at the minimum focus distance, depth of field is extremely small. For example, with a 100mm lens on an APS-C camera, it’s just 0.6mm at an aperture of f/2.8, so only areas that are within 0.3mm in front of or behind the focus point will be rendered sharply. Even at f/11, the depth of field is only 2.6mm.

Shallow depths of field aren’t too much of a problem when shooting flat two-dimensional objects, but things get tricky in 3D. Because focusing is so critical, you’re usually best off switching to manual focus, so you can focus on exactly the part of the object you want to be sharp. Fixing the camera in place and using Live View is helpful, as you can select a magnified view on the camera’s LCD for high-precision focusing.

Description: When you’re photographing three-dimensional objects, the shallow depth of field from a macro lens can cause problems

When you’re photographing three-dimensional objects, the shallow depth of field from a macro lens can cause problems

Sigma 50mm f/2.8 EX DG Macro

About the same size and weight as the diminutive Canon EF 50mm ‘Compact Macro’, this Sigma is similarly ideal as a lightweight prime lens for general purpose shooting. For macro work, it has more potential than the Canon, as it delivers a full 1.0x maximum magnification compared with the Canon’s 0.5x. It’s not an internal focus lens and, like the Canon 50mm, it features a magnification scale on its extending inner barrel. Here the display is accurate, however, whereas the Canon’s scale doubles up magnification factors.

Description: Sigma 50mm f/2.8 EX DG Macro

Sigma 50mm f/2.8 EX DG Macro

The basic micro-motor autofocus mechanism is a little shrill and sluggish but, unlike many macro lenses of around this focal length, there’s a focus limit switch thatworks either side of 25cm. This really speeds up autofocus performance in tricky conditions, where the lens might otherwise hunt between infinity and its closest focus distance.

We were very impressed with the levels of sharpness, all the way from its maximum aperture of f/2.8 to f/32. You can go even smaller, to a tiny f/45 aperture, but in this case image quality drops off very noticeably. For the price, this Sigma really is an over-achiever that’s equally useful as a standard prime lens.

Verdict

·         Price: $350

·         For: Small, light and versatile, with a reassuring build quality

·         Against: No internal focusing means an extending front element

Sigma 70mm f/2.8 EX DG Macro

The design of the Sigma 70mm looks very similar to the smaller 50mm version, although this lens lacks the antiquated aperture ring sported by its smaller sibling. That’s no great loss anyway – lens-based aperture rings are redundant when using Canon D-SLRs, as apertures are set via the camera instead.

Description: Sigma 70mm f/2.8 EX DG Macro

Sigma 70mm f/2.8 EX DG Macro

The focus limit switch works the same way as on the Sigma 50mm, but this time it locks focusing either side of 45cm instead of 25cm. That’s fair enough, as the longer focal length of the 70mm lens means its closest focus distance is 25cm anyway. There’s very much more travel at the short end, however, when the focus range is locked. Manual focusing is smooth and precise, although there’s no full-time manual override. The autofocus is quite sluggish, and our review sample suffered from some nasty vibrations towards the closer end of the focus range.

Optical quality proved very good, with plenty of resolving power even at the largest aperture of f/2.8. This is also true at the smallest aperture of f/22, although it’s worth bearing in mind that most macro lenses stop down to f/32, and the Sigma 50mm and 105mm lenses close all the way down to f/45.

Verdict

·         Price: $470

·         For: Good optical performance, precise manual focus ring

·         Against: Slow noisy autofocus, nasty vibrations at the short end

 

Other  
 
Top 10
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Finding containers and lists in Visio (part 2) - Wireframes,Legends
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Finding containers and lists in Visio (part 1) - Swimlanes
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Formatting and sizing lists
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Adding shapes to lists
- Microsoft Visio 2013 : Adding Structure to Your Diagrams - Sizing containers
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 3) - The Other Properties of a Control
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 2) - The Data Properties of a Control
- Microsoft Access 2010 : Control Properties and Why to Use Them (part 1) - The Format Properties of a Control
- Microsoft Access 2010 : Form Properties and Why Should You Use Them - Working with the Properties Window
- Microsoft Visio 2013 : Using the Organization Chart Wizard with new data
REVIEW
- First look: Apple Watch

- 3 Tips for Maintaining Your Cell Phone Battery (part 1)

- 3 Tips for Maintaining Your Cell Phone Battery (part 2)
programming4us programming4us
programming4us
 
 
programming4us