Compact primes for APSC with fast focus

[JustinVP]

Hey all, I could use some input on selecting a small/light prime for a6700 that has great focus performance. Bonus points for being able to handle dust/moisture.

This will be used for outdoors, almost exclusively shooting mountain biking under forest cover. It's a tough environment for auto focus. My daily driver is the 16-55 G, which I love, but looking for a light and portable option for spontaneous shooting.

Focus challenges mean I'm only looking at Sony lenses. I have the Sigma 30 1.4, it's not up to the focus task.

Here's the three lenses that I'm considering, all are small and light.

Sony E 35 f1.8 (APSC). I'm worried about it's ability to focus reliably as it doesn't have the better linear motors. F 1.8 is nice for playing around, though my action shots have a lower hit rate wide open, so I'll usually be shooting around F4.

Sony Sonnar T* FE 35 f2.8. Ticks most of the boxes. An older lens, so I'm wondering how well it focuses, apparently has fast motors. Tiny, which is appealing.

Sony Fe 24mm F2.8 G. Ticks all the boxes. I think 24mm on the crop sensor is a nice length with the 36mm equiv. Only downside is F2.8 vs the APSC Sony.

Anyone shoot action with the little 35 f1.8 and compare the focus hit rate with a Sony G lens? I think I might be falling into the wide aperture trap, and should probably go with one of the other two options... probably the 24.

 

[QuietOC]

I was frustrated by the options in this range back when I used APS-C except for some lovely inexpensive manual lenses. The Zeiss Touit 1.8/32 Planar was ok, but it has a rather slow micro motor. Some opted to use the FE 2/28.

The E 1.8/35 and FE 2.8/35ZA have fast linear motors. I only had bad optical alignment luck with both, but AF speed was not a problem.

I dislike the 2.8/24G, but its faults might be mostly cropped out on APS-C. There's the old 1.8/24ZA which I never tried.

The E 2.8/20 pancake is very small and quick. Maybe wider than you wanted.

Maybe consider the more recent third-party options?

 

[JustinVP]

The E 1.8/35 and FE 2.8/35ZA have fast linear motors. I only had bad optical alignment luck with both, but AF speed was not a problem.

I dislike the 2.8/24G, but its faults might be mostly cropped out on APS-C. There's the old 1.8/24ZA which I never tried.

Interesting, I'd read that the 1.8/35 is fairly slow to focus, though better than the Sigma 1.4/30 that I have. But you know how reviews are...

 

[Impulses]

The E 1.8/35 and FE 2.8/35ZA have fast linear motors. I only had bad optical alignment luck with both, but AF speed was not a problem.

I dislike the 2.8/24G, but its faults might be mostly cropped out on APS-C. There's the old 1.8/24ZA which I never tried.

Interesting, I'd read that the 1.8/35 is fairly slow to focus, though better than the Sigma 1.4/30 that I have. But you know how reviews are...

You might be getting the APS-C 35/1.8 OSS confused with the full frame 35/1.8, the latter is a very fast focuser (on par with any recent GM in that regard, and better when it comes to focus breathing).

 

[JustinVP]

You might be getting the APS-C 35/1.8 OSS confused with the full frame 35/1.8, the latter is a very fast focuser (on par with any recent GM in that regard, and better when it comes to focus breathing).

Ahhh, yep, that's it. I'm only looking at teeny tiny lenses right now, so the FE 35/1.8 isn't on my shortlist.

 

[Martin_99]

I never shot really fast action, only running children. But my bet in this case would be Sony Zeiss 24f1.8 and Sony 28f2. Both compact, fast aperture, fast AF. Newer small G 24/40/50 are probably even faster, but only f2.5/f2.8.

 

[QuietOC]

The E 1.8/35 and FE 2.8/35ZA have fast linear motors. I only had bad optical alignment luck with both, but AF speed was not a problem.

I dislike the 2.8/24G, but its faults might be mostly cropped out on APS-C. There's the old 1.8/24ZA which I never tried.

Interesting, I'd read that the 1.8/35 is fairly slow to focus, though better than the Sigma 1.4/30 that I have. But you know how reviews are...

There is a Sony DT 35mm F1.8 SAM that focuses pretty slowly especially when adapted to older E-mount cameras like the A6000. That was a cheaper lens for Sony DSLR/SLT cameras that came out a couple of years before the native OSS lens. The native OSS has a fast linear motor. The Sigma 30mm F1.4 DN has a stepper motor and had AF issues back then.

 

[Silat Shooter]

If you want tiny fast focusing prime for APS-C, the 15mm f1.4 is a gem. My favorite APS-C lens. The 35mm f1.8 (Full Frame) is plenty fast focusing and a favorite of video shooter because it has no focus breathing. But it's not tiny. Not horribly big as say a f1.4 FF lens.

It's not a bad idea to look at small FF lenses for APS-C, as it gives you the option to add a FF body at some point if you so chose. There are many solid small(ish) compact FF prime lenses from Sony G, Sigma, Samyang, Viltrox. I also have the Sigma 90mm f2.8 and use it as a tiny 135mm APS-C equivalent and that too is a gem.

But I find tiny lenses make shooting more fun for me. They're easier to carry and don't draw attention to me.

 

[UncleVanya]

I never shot really fast action, only running children. But my bet in this case would be Sony Zeiss 24f1.8 and Sony 28f2. Both compact, fast aperture, fast AF. Newer small G 24/40/50 are probably even faster, but only f2.5/f2.8.

The ZA 24/1.8 has good reviews:

In the second review listed he compares image quality to the 35/1.8 oss and the 18-135.

 

[jhunna]

Hey all, I could use some input on selecting a small/light prime for a6700 that has great focus performance. Bonus points for being able to handle dust/moisture.

This will be used for outdoors, almost exclusively shooting mountain biking under forest cover. It's a tough environment for auto focus. My daily driver is the 16-55 G, which I love, but looking for a light and portable option for spontaneous shooting.

Focus challenges mean I'm only looking at Sony lenses. I have the Sigma 30 1.4, it's not up to the focus task.

Here's the three lenses that I'm considering, all are small and light.

Sony E 35 f1.8 (APSC). I'm worried about it's ability to focus reliably as it doesn't have the better linear motors. F 1.8 is nice for playing around, though my action shots have a lower hit rate wide open, so I'll usually be shooting around F4.

Sony Sonnar T* FE 35 f2.8. Ticks most of the boxes. An older lens, so I'm wondering how well it focuses, apparently has fast motors. Tiny, which is appealing.

Sony Fe 24mm F2.8 G. Ticks all the boxes. I think 24mm on the crop sensor is a nice length with the 36mm equiv. Only downside is F2.8 vs the APSC Sony.

Anyone shoot action with the little 35 f1.8 and compare the focus hit rate with a Sony G lens? I think I might be falling into the wide aperture trap, and should probably go with one of the other two options... probably the 24.

Fast focus? Get the latest Sony glass with the linear motors.

That leaves the 24G. I have used the 40G on the A6700 and it is a wonderful combination. I expect you will get the same, from the 24G and gain some corner sharpness from it being a FF lens.

As an aside the 28/2 is also a really good lens on apsc. But get the 24G and all the features that come with it, you won't regret it.

 

[JustinVP]

Fast focus? Get the latest Sony glass with the linear motors.

That leaves the 24G. I have used the 40G on the A6700 and it is a wonderful combination. I expect you will get the same, from the 24G and gain some corner sharpness from it being a FF lens.

As an aside the 28/2 is also a really good lens on apsc. But get the 24G and all the features that come with it, you won't regret it.

Yep, this is where I've landed, I'm pulling the trigger on the little 24G. It's a great focal length for my APSC use-case, and when I take a step back, the fast/reliable focus is by far my top criteria for this ultra-portable setup.

I suspect most photographers would be surprised at how much even the best systems struggle to nail focus in the settings I usually shoot. Moderate light with a mountain biker weaving through trees makes focus tracking a challenge. Often in dappled light where the only good shot is 1 frame in a nicely lit ray of sun. It's a challenge, but a fun challenge.

 

[DutchMM]

That's an interesting observation. Have you tried registering faces for the competitors in whom you are interested?

 

[JustinVP]

That's an interesting observation. Have you tried registering faces for the competitors in whom you are interested?

I should try that again, but it didn't make a difference last time I played with it on the a6400. Moving to the a6700 this spring, which I'm told has a noticably better hit rate on the stuff I shoot.