Flash AF-assist enabled

[Gianluke]

New petition for flash AF-assist lamp enabled

 

https://www.change.org/p/sony-corporation-kazuo-hirai-enable-the-use-of-af-assist-lamp-from-external-flash-on-sony-mirrorless-cameras?recruiter=297208305&utm_source=share_petition&utm_medium=facebook&utm_campaign=share_facebook_responsive&utm_term=des-lg-no_src-no_msg

 

Inviato da LG G4 mobile

[simonomis]

Yes guys let's push Sony to enable this simple and basic function on our mirrorless cameras! Every cheap DSLR has it since 1970!

Sign up the petition: https://www.change.o...g-no_src-no_msg

[michelb]

I honestly think it can not be done for the following reasons with the present flash system because:

 

- It is derived from the A-Mount cameras ( Sony and Minolta before) that are all Phase detection AF that required the flash or camera AF assist to emit a PATTERN (not just a light like you get from your E-Mount camera. The pattern is actually a series of lines that are at a pre-determined distance that the camera AF sensors that are hidden somewhere in the mirror box need to recognize to help the camera calculate by how much and in which direction to turn the focus ring. These weak lines would be of no help to your E-Mount camera that is relying on contrast detection. The newer sensors with PDAF could theoretically use them provided the AF on-sensor was reproducing the size/shape and distances that are present in the A-Mount cameras and flash units. But then probably only 8 to 10 AF sensor zones could be put to use due to the limitations of this pattern.

This pattern actually evolved throughout the years due to the multiplication of AF sensors from 1 to 3 to 8 and even more.This is why on some older Minolta flash units the AF assist beam would not work and be disconnected when an older flash would be used with newer camera with a different AF sensor array.

Even the first generation of Minolta AF cameras (1985)  with only a single AF sensor could actually focus accurately on blank walls in total darkness due to this pattern ( i wish i could find a demonstration of this pattern in my older documentation ). The assist light in your A7 can not help to do this if there is not a contrasty subject it can detect to focus on. An A-Mount camera can due to this.

 

- The AF assist beam from these flash units is much weaker in intensity than the AF light you get from your E-Mount cameras AF light so you would actually be getting less AF assist than what you are used to with your camera

[simonomis]

Thx for your useful contribution, i think you could also be right about current flash system...and that's why Sony should hurry up and make a new line of flash for their mirrorless cameras!  By the way i tried myself to use the pattern created by my Nikon SB910 flash to focus on the same target with my sony A7RII. It worked quite well..faster than with the in body red led light so it is not impossible to develop for a big company like Sony.

[michelb]

Thx for your useful contribution, i think you could also be right about current flash system...and that's why Sony should hurry up and make a new line of flash for their mirrorless cameras!  By the way i tried myself to use the pattern created by my Nikon SB910 flash to focus on the same target with my sony A7RII. It worked quite well..faster than with the in body red led light so it is not impossible to develop for a big company like Sony.

I wonder how you achieved this since the Nikon language and the Sony language between camera and flash AND their connectors locations are all different !!!!