Sony 30mm F2.8 DT Macro SAM hands-on!

F22: What is that I see, right in front of me?


F2.8: Speaker grilles!


F14: Stereo mike.


F2.8: More speaker grilles!


What else, but the new Sony 30mm F2.8 DT Macro SAM lens! It features SAM (Smooth Autofocus Motor) and an AF/MF switch, and can focus to 129mm from subject to sensor plane (or 20mm from the front of the lens). Interestingly, they mark the inches with "in" where there is space.

It can capture an image at 1:1 magnification - that is, the surface area captured is equal to the sensor size (23.5mm X 15.6mm on the A700 for example).


From the underside at F2.8; notice the longitudinal chromatic aberration (the reddish outline in front of the focus point, and the greenish outline behind the focus point.)

A slight rant - people tend to confuse longitudinal chromatic aberration with lateral/transverse chromatic aberration (which appears towards the sides and corners of wide-angle lenses) and purple fringing (which appears at the point of focus, especially with white on black detail.)

More reading on the various types of chromatic aberration, here:
http://wiki.panotools.org/Chromatic_aberration


F2.8 (100% crop from the Sony Alpha 900.) This lens has longitudinal chromatic aberration (or LoCA in short.) LoCA is common in Sony, Minolta and Zeiss lenses, and it adds to the color of the out-of-focus areas, giving Minolta lenses their definite look. My old Carl Zeiss Jena Flektogon 35mm F2.4 had a tendency to bring out ultramarine-blue purple fringing, though (which is a bad thing, but can be reduced by choosing a darker aperture.)


F2.8: 30mm on APS-C gives the same angle of view as a 45mm lens on a full-frame camera. This is often considered 'normal' - neither wide nor tele. Depending on how you compose, you can make it seem wider or more telephoto.


F2.8: Real shallow.


F22: The obligatory shot. You know what this is.


Previously my experience with SAM lenses is that you might've been able to turn the focus ring when the body is set to MF, or focus is achieved and the focus screw clutch disengages (body DMF - Direct Manual Focus). However, the instruction manual tells you not to! No wonder it does feel a bit rough.

No matter what, you need to set the AF/MF switch on the lens to MF, in order to turn the focus ring. You can still use AF/MF or DMF on the body to stop focusing - just don't turn the ring.

These warnings are written in the instruction manual for a reason. The manufacturer will not fix your lens for free under warranty if you have damaged it this way, because they have already warned you! Same reason why McDonalds Apple Pie boxes state: Caution: Contents May Be Hot. So if you burn your tongue, you can't sue McDonalds because they have already warned you.


F2.8: At F2.8, it is sharp, but not too sharp (like the Tamron 60mm F2.0 Macro DiII, also an APS-C 1:1 macro lens). This makes the lens good for walkaround purposes, where the kit lens would usually stop you from getting too close (exception being the Sigma 17-70mm F2.8-4.5 EX DC and Sigma 18-50mm F2.8 EX DC, with exceptional minimum focusing distances of 20cm).

It reminds me of my wonderful time with the Carl Zeiss Jena Flektogon 35mm F2.4 M42 lens - it could focus to 19cm close! So instead of zooming in (not possible on this prime lens) I would just get closer to the subject until I filled the frame with my subject. Great fun for walking in the park or the woods.

Shallow, narrow-minded camera-owning people will tell you that macro lenses must have long focal lengths. Obviously, their idea of macro is only insects (which are often, painfully boring because they tend to throw composition out of the window and go into "oh you guys are all about gear... hey look here's the same insect at 5 different magnifications all higher than 1:1. Oh yes, all 5 pictures are the same thing, same angle.")

These macro nuts look at cropping as an evil sin, but they do not hesitate to take a few pictures at different focus points and merge them together (focus stitching.)

Last I knew, shooting macro means shooting anything small. A macro lens can be used for close-ups. You can shoot flowers. Grass. Miniature figurines. Patterns and details you never knew existed.

If you shoot the same thing with a long lens, you will get a different perspective, and shallower depth of field, which does not help with macro - you often need to step down to F16-F32 to get something tiny in focus! You also need a lot of light from your flash. A shorter focal length is easier.

With a wide macro, you can get a shot like this:


17mm F8. You can get a flower and a building in the same shot! In retrospect I should've stopped down to F22. And borrowed the lens for a much longer period of time, it was great fun!

Edited by albnok - 16 September 2009 at 18:52

Thanks, i was looking at this lens early today on Adorama.

So cool to see a report on this lens. I have been coveting one at least for its wide side. Thanks for a guide too on the possibilities I did not think of. Now to get the price and start saving.

How's the auto focus speed on this lens with SAM?

Nice writeup!

With SAM lenses, we have no idea how many gear turns it takes.

I would say that focus is not instant, but it certainly is not slow to acquire focus, either.

analytical: Thanks for the note on DMF. Updated original post.

The focus ring is sized as it is... not that hard to grab, really. Then again I am used to my Minolta 50mm F1.4 Original's focus ring...

Wow on the samples. I wonder how would it fare against the Tam60/2 or Sig70/2.8 --- I'm thinking macro :P

This is the first DT lens that I totally forgot to bypass the auto-crop (press the lens release button and turn it 1 degree loose, so it holds in place but does not contact; turning it looser will stop down the aperture blades.) I guess I was too engrossed with shooting macro that I forgot to take full-frame vignetting tests!