How Accurate is Contrast Peaking Manual Focus?

bwcolor · 10-09-2011

My NEX-5N was set to Red contrast peaking and I had a Leica 90mm APO ASPH set to f/2.0. It is really great to be able to get a solid positive feedback on your focusing when the white of the eye turns bright red at f/2.0. What is less agreeable are the results. Some of my shots absolutely nail focus and others do not.

I was wondering if others were having mixed results with contrast peaking and fast lenses?

How are fast lenses and focus peaking working with the GXR?

Shade · 10-09-2011

It's quite accurate. But if you're using F1.4 or brighter, it may not be TACK SHARP RIGHT ON SPOT sharp. It's in the sharp-zone.

Nettar · 10-09-2011

I made the same observation, bwcolor. I was a happy manual focuser on the Nex 5, using 14x magnification, until peaking came along, and of course I compared the two approaches. I found that, when using a long lens at a wide aperture, the short space of time between when I got focus dead right, using 14x magnification, and pressed the shutter button, was sometimes enough for the subject to move just a little, and throw focus towards the edge of the range of depth of field. For example, focusing on an eye using 14x (or 7x) magnification, and taking the picture perhaps half a second later, is enough for the subject to have moved a little and the plane of focus to be on their nose instead of an eye. It's much the same with focus peaking, as long as the point you want to be in your narrow line of focus is of sufficiently high contrast for a "peak" to occur there. (If it's not then it's back to 7x or 14x magnification...) I found that peaking is a bit faster, but just a little bit less accurate (even after I acquired reasonable experience), so the net outcome is still not the 100% perfectly focused results I had anticipated! But that is life, I guess -- nothing is perfect, especially me... Nettar

GaryLH · 10-09-2011

I think kshapero on another thread nailed it with his suggestion. My eyesight not that great as I get older. He suggested using BW mode but shot raw. This way BW is not permanent, but BW LCD mode gave better contrast in order to c with your own eyes when peaking has nailed focus which is acceptable sharp. I find that peaking works fine for me in situations where speed is more important than razor sharp. But 7x mag is only way to nail it Razor sharp for me. But I attribute this to my poor eyesight.

Gary

kossi008 · 10-09-2011

Quote:

Originally Posted by GaryLH

... I find that peaking works fine for me in situations where speed is more important than razor sharp. But 7x mag is only way to nail it Razor sharp for me. But I attribute this to my poor eyesight.

Not at all. Especially for slow wide-angles, peaking is better than nothing, but I always use 7x mag when I have the time...

rxmd · 10-09-2011

"Focus peaking", a.k.a. contrast detection, works by comparing local contrast across the frame and selecting those regions where there are sharp edges, that is where there is a lot of contrast relatively speaking. Eyesight has little to do with it.

Consequently, it works less well with wideangles (where everything is more or less in focus and it is hard to pick those regions that are a little more in focus). It also doesn't work that well with slow lenses or lenses stopped down (where there is again a broad depth of field range within which everything is somewhat in focus).

grdglass · 10-10-2011

What's the consensus? Is the EVF required when using focus peaking? I would imagine it would help, but is the LCD okay also?

ferider · 10-10-2011

Quote:

Originally Posted by bwcolor

My NEX-5N was set to Red contrast peaking and I had a Leica 90mm APO ASPH set to f/2.0. It is really great to be able to get a solid positive feedback on your focusing when the white of the eye turns bright red at f/2.0. What is less agreeable are the results. Some of my shots absolutely nail focus and others do not.

I was wondering if others were having mixed results with contrast peaking and fast lenses?

How are fast lenses and focus peaking working with the GXR?

You realize you have less than one cm DOF at close focus ? Meaning, however good the camera or focus method is, if you or your subject only move that much after focusing, you'll be off.

rxmd · 10-10-2011

Quote:

Originally Posted by grdglass

What's the consensus? Is the EVF required when using focus peaking? I would imagine it would help, but is the LCD okay also?

It's easier with the EVF, if only because you're less likely to move your head than your hands after focusing.

Shade · 10-10-2011

Focus peaking is really a great feature despite its flaws. Especially when you need fas focusing and acceptable image. I said acceptable here, not spot on.

Nokton48 · 10-10-2011

I downloaded it into both Nex3's, tried it for a bit, then turned it off.

I still prefer the Clearviewer for my uses. I'm happy with this gear, for what it is.

kshapero · 10-10-2011

Quote:

Originally Posted by GaryLH

I think kshapero on another thread nailed it with his suggestion. My eyesight not that great as I get older. He suggested using BW mode but shot raw. This way BW is not permanent, but BW LCD mode gave better contrast in order to c with your own eyes when peaking has nailed focus which is acceptable sharp. I find that peaking works fine for me in situations where speed is more important than razor sharp. But 7x mag is only way to nail it Razor sharp for me. But I attribute this to my poor eyesight.

Gary

True but even with that method, I still use MF assist for wide apertures.

bwcolor · 10-10-2011

Quote:

Originally Posted by ferider

You realize you have less than one cm DOF at close focus ? Meaning, however good the camera or focus method is, if you or your subject only move that much after focusing, you'll be off.

Yes, so someone needs to shoot from a tripod using fixed subjects.

Also, I found that contrast peaking is useless in bright sunlight using the rear LCD on a 5N. Maybe it is me, but I just could not see the screen. This is the major reason that I'm returning the camera.

GaryLH · 10-10-2011

Quote:

Originally Posted by kshapero

True but even with that method, I still use MF assist for wide apertures.

Yep. I ended up using that way too when I have the time. After shooting a shot, I tend to move focus setup to my default which is the hyper focal point to catch anything I have no time for.

Gary

Nebster · 10-10-2011

I find it's just not that good. I shoot a lot of flat-field, static subjects. I usually want to print big, so I need that magic critical sharpness, right in the sweet spot of the DOF. (Losing the AA filter would be a whole additional little boost, but that's another topic.)

I find the peaking isn't quite good enough, and the work required to really nail it (slight movement to see when you get the "most" peaking) is no better than just using the zoom feature.

And when trying to shoot babies or whatever, I find in a lot of situations I'd rather be in zoom mode, on the eyeball or what have you, and then fire at peak focus. There are only some situations where I'd rather be at 100% view with peaking on. (Multi-subject dynamic situations, bright sunlight, and maybe a few others.)

So I guess it's okay for casual snapshotting and as a complement to zoom. But zoomed live view nets more keepers for my most common styles of shooting.

Ronald M · 10-10-2011

You are expecting way too much from those toys. They are built for slow short lenses.

90 2.0 is taxing to a Leica and you can hold it steady unlike the Zombie cameras.

kshapero · 10-11-2011

Quote:

Originally Posted by bwcolor

Yes, so someone needs to shoot from a tripod using fixed subjects.

Also, I found that contrast peaking is useless in bright sunlight using the rear LCD on a 5N. Maybe it is me, but I just could not see the screen. This is the major reason that I'm returning the camera.

Works well if you shot B/W but still a hassle

xpanded · 10-13-2011

I prefer magnification with NEX-3 and Contax G 45mm over peaking. Cannot tell if it is only my sample (camera body + lens + 2 x photographer (since he is usually the weakest link)), but I rarely get sharp pictures with peaking whereas magnification (7 times) usually is a hit.

Even at f8 or f11 are the results with peaking usually only sharpish and not sharp.

Edit: Initially I thought that maybe the medium-priced adapter was to blame since it is a little rough, but since the magnification mode is OK apparently not.

Whatever the focusing mode I really adore the NEX for allowing me to use my Contax again.

jsrockit · 10-13-2011

Damn, I was interested in the NEX-7 until I read this... I hate magnification and thought focus peaking was the answer in an EVF. Of course, I'll try for myself, but I'm not as excited anymore.

xpanded · 10-13-2011

Don't get your hopes down just because of me :-)
It may indeed be a man-machine interface problem.
And it is likely that it is much easier to see in the EVF.
Or maybe we have just been spoiled over time getting used to almost 100% accurate focusing?

douglasf13 · 10-13-2011

Focus peaking, just like rangefinder focusing, takes quite a bit of practice to perfect, and, like rangefinder focusing, I still occasionally miss things. However, overall, once things like parallax and focus shift are taken into consideration, I'd say I'm now a bit more accurate with focus peaking than I am with a rangefinder.

Practice makes perfect!