Focusing with 503CW

[voodooloy]

Hello,

I'm a new Hassy user. I'm having problem focusing with my 503CW and acute matte D split screen. I noticed when the split area is align....the overall screen area is soft. Is that a problem? It is very uncomfortable, though the picture came out to be in focus.
Will changing the screen to after market once like Bright Screen or Beattie Screen help?

Please advice. Thank you!

 

[simonpg]

Roy, I too use a 503CW and think I know what you mean. No, this screen is very good and bright. Maybe what you are seeing as soft is the fact that the lens is wide open unless you activate the DOF preview control on the lens. If the lens focal length is greater than 80mm the areas outside the split prism logically will be softer where the plane of focus is closer or further away.

 

[fotografz]

Yes, you are focusing with the lens aperture wide open to the maximum for maximum brightness.

This allows you to "see" the exact focus point. But when you shoot, the lens automatically stops down to the set aperture. If that aperture is say f/8 then more of the scene will be in focus than what you see in the view finder when focusing. As stated above, if you activate the stop down lever on the left side of the lens, you can then see what the effect of f/8 will be. But f/8 may be too dark to focus on the prime subject accurately. That's why modern lenses have the automatic stop down feature.

Try it and see what we mean.

 

[qnu]

Focussing screen brightness is not the main point why one shouldn't focus with the lens stopped down.
More important is that wide open DOF is minimal, and it is clear where the plane of focus really is, while when stopping down you are guessing, increasingly so when stopping down further.