Sweet Sigma

As a general rule I try to concentrate most of my discussion on photography.  That includes the enjoyment of our obsession, the art of the medium and the challenges of getting a 'keeper' shot.   There are plenty of websites that focus on gear to the point of forgetting what the gear is actually used for. 

But last night and this morning, sorting though the images from the last butterfly shooting expedition, I was just taken by how good the shots were from the very moderately priced Sigma 105mm f/2.8 macro lens are. 

For butterflies I almost always use this lens along with the Sigma 1.4 teleconverter.  That gives me an effective 147mm.  Plus the 1.5 crop factor from using an APS-C camera and we're out to an effective 225mm f/4 macro lens.  I often use the lens without the teleconverter for smaller subjects that I can get really close to.  And occasionally for larger subjects as well.  Automotive detail shots would be one example.

This image is a 100% crop from the processed TIF file at the original resolution.  The important thing to keep in mind is that it's a real world shot, not a studio setup.  No keeping the bug in the fridge to slow it down.  The shot was done in the middle of a hot summer day, hand held, having to bend over and shoot from an awkward angle.  No flash was used either, just natural sunlight. 
The setup was Aperture Priority, f/5.6 at 1/320th and ISO 200.  Depth of field is razor thin but f/5.6 is also in the golden zone for sharpness with this lens. 

When shooting butterflies I have the Sigma optical stabilization turned on, and the Sony in-camera stabilization turned off.  In my non-scientific experience, 105mm is in the crossover zone. For telephoto work having stabilization built into the lens seems to work better, for shorter focal lengths, using the system built into the body gets the nod.  I have not done extensive back to back testing so this is more of a subjective analysis.  Other people and gear combinations may yield different results. 

Focus was manual using Sony's Focus Peaking.  Always a challenge when the critical part of the subject is moving in and out of focus second by second.  When using this method you will not get perfect critical focus every shot, but practice helps a lot, and when you nail it, well, that's just a great feeling.