PDN PhotoPlus 2013

[Rob C]

And before "full frame" became the object of Big Sensor fetishist desire it was a miniature format.   

-Dave-

Q.E.D. baby!

Rob C

[Isaac]

And before "full frame" became the object of Big Sensor fetishist desire it was a miniature format.

A convergence of stills with movies :-)

[barryfitzgerald]

Folk get that and don't care at all.

What they care about is that their camera now lets them do stuff they couldn't do before.

Which is fine but do I have to have a dumb video button sitting there which could be useful for something else?
Making a product do extra bits is fine no problems at all, it's when you compromise stills shooting to get there that's the problem.

Take a look at Sony, they put a mirror in the light patch that does not move, and robs half a stop of light.  All so you can have AF at f3.5 for video  
I have one myself, I got over it..but still why would any video shooter want the aperture fixed at f3.5 for AF?

[BJL]

Which is fine but do I have to have a dumb video button sitting there which could be useful for something else?

Hopefully not: sensibly designed cameras like the Olympus EM5 allow the video button to be reprogrammed; mine currently does the MF/AF toggle.

[Isaac]

Which is fine but do I have to have a dumb video button sitting there...

Of course not! Compact cameras don't have dumb video buttons and they do video.

All so you can have AF at f3.5 for video

All so you can have continuous AF for a burst of photos. (Even my old SLT-35 has dedicated 7fps at reduced resolution.)

[barryfitzgerald]

Of course not! Compact cameras don't have dumb video buttons and they do video.

All so you can have continuous AF for a burst of photos. (Even my old SLT-35 has dedicated 7fps at reduced resolution.)

Have to say I'm not seeing any improvement for tracking AF, in theory you should. (not that it's bad it's just wasn't a problem)
Reality is predictive AF has been around for ages, I can't get my film Dynax 7 to miss the AF is that accurate

Sony have this odd concept of what they think people want, rather than actually asking them 
There are no doubts in my mind SLT has more to do with video than stills shooting.

70d's on sensor phase detect changed things for video folks

[dreed]

70d's on sensor phase detect changed things for video folks

Not only video, stills too:

dpreview: 70D autofocus testing

For ages people have been saying how good PDAF TTL is but quite clearly "live view" autofocus is better and maybe now sensor PDAF too.

[hjulenissen]

Not only video, stills too:

dpreview: 70D autofocus testing

For ages people have been saying how good PDAF TTL is but quite clearly "live view" autofocus is better and maybe now sensor PDAF too.

I don't believe that this test shows LV/on-sensor PDAF to be universally "better" than off-sensor PDAF. I'd rather say "different" or "better for some tasks".

Someone (was it Erik?) said that there are (at least) two performance characteristics of an AF system: getting accurate focus of the thing that the photographer wants to be in focus, and getting it fast. Getting the right focus 100ms late can make the shot irrelevant, and getting an AF confirmation blazingly fast can make the shot irrelevant if it is off by 1 meter.

I would guess that speed is less critical to many landscape photographers, compared to e.g. sports.

-h

[barryfitzgerald]

I've used a 70d and I can say that AF test on DPR is clearly a defective unit showing strong back focus across a range of lenses.
Even the old budget KM DSLR's I have would nail those AF shots no problem (high contrast static targets) just about any phase detect AF system would hit them.

But lemon units do get out there sadly (I personally have had issues with Nikon's AF accuracy)
The only surprise there is DPR actually used that unit, and didn't ship it back to Canon.

I don't believe that is representative of a well calibrated DSLR for AF

[Isaac]

Sony have this odd concept of what they think people want, rather than actually asking them

That description doesn't seem to match what we see from Sony, I think TMARK's description works better.

There are no doubts in my mind SLT has more to do with video than stills shooting.

When AF improves for photos, why do we care if the technology driver was video?

70d's on sensor phase detect changed things for video folks

I haven't used 70d, but this doesn't sound so good -- "Worse still, the screen blacks out completely during continuous shooting, making the whole thing something of a guessing game, particularly when panning to follow a moving subject. This means that Dual Pixel AF is effectively limited to being a 'one shot' mode when shooting stills."

[barryfitzgerald]

I've not tried the 70d in cont shooting mode so can't comment on that, but for video it's a far better solution that Sony's SLT (problem is as said fixed aperture which is crazy for AF)

I've no problems with Sony's AF, seems decent enough to me. But I'm not sure the SLT mirror has made it better than normal DSLR's hands on with other makers I would say no it has not.

Sony seem to be trying lots of different things in the hope something will stick, I'm not sure that's the best strategy to have. They could have done a lot with A Mount, but have had many problems over the years, and not been very satisfactory in resolving issues or thinking things through very well. A real mixed bag at times. My only interest in Sony is my fairly good selection of Minolta/Tamron glass and somewhere to put it. I'm not convinced they are making products that meet the needs of their current customers, or know how to develop A Mount properly.

[Isaac]

Sony's SLT (problem is as said fixed aperture which is crazy for AF)

...why would any video shooter want the aperture fixed at f3.5 for AF

I've just wandered inside and outside, with video on A35, and afaict shutter and aperture are adjusted automatically. afaict Video exposure matches AUTO photo exposure.

What makes you think aperture is fixed at f3.5 for video?

[ErikKaffehr]

Hi,

That's correct. Phase detect AF needs large apertures, so Sony video doesn't stop down in AF mode. Stopping down is perfectly OK in MF mode. Video mode lacks view magnification in LV, a mess. Switch to still mode, disable AF, focus manually and switch back to movie mode. A bit brain damaged …

Best regards
Erik

I've just wandered inside and outside, with video on A35, and afaict shutter and aperture are adjusted automatically. afaict Video exposure matches AUTO photo exposure.

What makes you think aperture is fixed at f3.5 for video?

[Isaac]

That's correct.

Please point me to somewhere that's documented, or suggest some way to check the camera.

[barryfitzgerald]

I've just wandered inside and outside, with video on A35, and afaict shutter and aperture are adjusted automatically. afaict Video exposure matches AUTO photo exposure.

What makes you think aperture is fixed at f3.5 for video?

It is fixed for autofocus.
If you put the camera in manual focus and use the P setting it will adjust shutter speed and aperture for the exposure.
As soon as you use AF, then it's fixed to f3.5, even in really dim light, or really bright light.

I can understand that at a certain point the AF won't have enough light to work, but I don't understand why it's fixed at f3.5. With faster lenses you can't use AF take advantage of the lens speed, and I can't see why the AF won't work at f5.6 also.

It's just a strange oddity that Sony have for some reason. Same as the video crop (even with electronic steady shot off) you get a 1.8x crop
Considering Sony should have tons of video experience, they seem to have come up with a half baked solution. The lack of audio gain control another limitation.

[Isaac]

Please point me to somewhere that's documented, or suggest some way to check the camera, or say how you've reached that conclusion.

[barryfitzgerald]

Please point me to somewhere that's documented, or suggest some way to check the camera, or say how you've reached that conclusion.

Maybe it didn't occur to you that I might own a Sony SLT camera? 
I've also used the following models A57/8/65/77 but not the A99

I also know because I've also got an A57
BTW the A65/77 are capped at ISO 1600 for video too (A57 is capped at 3200)
Lots of limitations with video and Sony's SLT's

[Isaac]

On the contrary, you'd already mentioned owning SLT in several other posts.

Now I've been in the closet, I see that AF video is dark compared to MF video f1.8 but I still can't quite figure out what AF video does when the scene's bright.

[barryfitzgerald]

The only control I see in P mode and AF is it will adjust the shutter speed (up/down) or drop/raise the ISO levels
I'm not sure why they did it like this, I get the "auto make it easy take" for some users.

But I think it's a bit odd to limit things like this.
Maybe they will address these issues on the next round of cameras. I'd love to say Sony might update the firmware, but that's not likely to happen (Sadly)

[ErikKaffehr]

Hi,

No 1.8X crop, I would guess 0.96x horisontally, 1920 / 2000.

A99 SLT has gain control on audio. You can choose aperture/shutter freely when in manual focus. While aperture is locked at f/3.5 in AF mode, I don't know.

Best regards
Erik

It is fixed for autofocus.
If you put the camera in manual focus and use the P setting it will adjust shutter speed and aperture for the exposure.
As soon as you use AF, then it's fixed to f3.5, even in really dim light, or really bright light.

I can understand that at a certain point the AF won't have enough light to work, but I don't understand why it's fixed at f3.5. With faster lenses you can't use AF take advantage of the lens speed, and I can't see why the AF won't work at f5.6 also.

It's just a strange oddity that Sony have for some reason. Same as the video crop (even with electronic steady shot off) you get a 1.8x crop
Considering Sony should have tons of video experience, they seem to have come up with a half baked solution. The lack of audio gain control another limitation.