They say the best camera is the one you have in hand. This is true, but it also leads to a conundrum. Which lens should I have on my camera in which circumstances? Obviously, you know when you need to use a 200-600 vs a 24-70, but the 70-200 overlap with both those lenses is trickier. If I’m planning to be at a feeder on an overcast day, do I want to shoot at 200 f/4 with the 70-200 or have the flexibility to zoom in of my 200-600 with the cost of less light? Another consideration that we needlessly obsess over is which lens will be sharper at a given point. And that’s how I got to writing this post. After recently picking up a first-generation Sony 70-200 f/4 G lens, I was curious about some overlap points:
- At 70 mm what is the difference in sharpness vs my Sony 24-70 f/2.8 (v1) GM?
- At 200 mm how does the sharpness compare to the Sony 200-600 f/5.6-6.3?
These questions partly feed into my mental algorithm of what lens I want on my camera when. For example, if I’m planning to snap some candid portraits when traveling, what will the trade-offs be between the 24-70 (faster, shallower depth of field, presumably sharper) and the 70-200 (more background compression and easier to catch candid moments without being in their face)? I decided to print out a test image sheet and compare the results side by side here on my blog. It can be surprisingly difficult to find comparisons of mismatched lenses as most comparisons are in the same class (ie Tamron’s 70-180 vs the Sony 70-200) rather than optical qualities of adjacent focal lengths. I wanted to contribute something that will hopefully help other curious photographers like myself.
Test Parameters
I put the camera on a tripod and taped the chart to a wall in my office. I put a video light on the image to help with lighting. All images were shot at 1/100 (mainly because I had to semi-handhold the 200-600 with the tripod I had on hand), a series of apertures, and whatever ISO would correctly expose the image. Rather than using a flash setup (mainly due to being too lazy to) I controlled the exposures with ISO between different apertures because I wanted a real-world wildlife/landscape/travel experience; I rarely shoot with artificial lighting. I’ve not listed the ISOs but they were no more than 2,000 and were within 1/3rd stop of each other at the same aperture on the compared lenses. After I cropped the images as close as I could and matched their exposures and white balance.
Sony 24-70 GM vs 70-200 G (version 1 of both lenses)
I have the older versions of both these lenses. Photographer math says they’re basically free if you buy an older, used lens. Right? Right???
On all the comparisons I’ve but the shorter lens on the left hand side and the f/ below the image.
And for a point of comparison wide open, here is one with mixed apertures and ISOs.
Sony 70-200 f/2.8 GM vs Sony 200 – 600 f/5.6-6.3 G
Again, both lenses are first (only in the case of the 200 – 600) generation. This time, some comparisons at 200 mm.
Conclusions
The great thing about testing our pre-conceived notions is how we can find unexpected gems in our toolkit. I set out to find out how much sharper my GM lens was than my G lens and found the opposite was true! I imagine in this case it’s more an issue with the very end of the focal range as on the whole I’ve been very happy with my 24-70’s performance. But I’m definitely seeing more detail out of the 70-200 at 70 mm than the 24-70. I didn’t notice as much of a difference in detail between the long lens and the 70-200 but the extra light capture and being much easier to handle (size/weight) is another plus for it when at some feeder set-ups where you can get close in, like with hummingbirds.