Info xt10 focus behaviour

[silver_1976]

Hi,

I noticed that using single point focus when I half press the shutter the EVF while is checking focus is really bright, overexposed (it's a split second however, the shot is ok). I noticed this in a very sunny day.

I always use multi point focus and when it's checking focus this issue doesn't occur (even in a very sunny day)... Is it a normal behaviour?

 

Thanks

[Tikcus]

in the uk this week we're lacking sunny days, I'll test tomorrow (assuming i remember) on my xt-10 with latest firmware, see if i notice anything different

 

 

edit

 

if you can please post other settings? such as are you shooting in manual exposure, aperture priority, shutter priority, etc
Then I can try and replicate the issue

 

thanks

Edited June 13, 2016 by Tikcus

[silver_1976]

hi, thanks for the reply,

I'm shooting in aperture priority, the lens is xf 18-55 and I noticed that the issue is more evident at 55mm than 18mm.

 

thanks.

[DarnGoodPhotos]

It opens the aperture to maximum while getting focus. If it didn't, then getting focus in low light would be very hard.

Edited June 14, 2016 by darngooddesign

[silver_1976]

thank you darngodesign,

I just wonder why in multi point focus the camera doesn't have this behaviour (doesn't overexpose EVF..)

 

 

[Tikcus]

shooting in full manual with xf35 F/1.4 underexposed i did not notice any difference in evf brightness while getting focus, (was not in sunshine)

I'd hazard a guess if you are letting camera control shutter, and iso it is probably adjusting one or other when you half press 

[silver_1976]

In aperture priority I guess I ler the camera control shutter, the strange thing is that with multi point focus and the same conditions the camera doesn't "overexpose" to recalculate exposion

 

 

[sandroamt]

Just guessing...

 

it could be related to the phase vs contrast focus:

phase focus may NEED full open in order to differentiate light arriving to the sensor from different directions

 

I did try:

camera on tripod aiming at a window whith some object in the dark; if you use the spot in the central area (phase detect) aiming the spot at the dark object, to check the focus the display overexposes.

After I turned a little bit the camera and I shifted the spot focus to a lateral zone (contrast detect) aiming the spot at the same dark object and now checking the focus the display do not overexposes.

Edited June 16, 2016 by sandroamt

[silver_1976]

I see.. this is a very reliable theory.. I thank you!