Focus Issue with Hassy 110mm TCC - Normal?

[regit]

Got myself a 110mm TCC (early FE) to be used on a 203FE. At close up and wide open, it focus alright. But when rack up to infinity, again at f2, the center of the image is out of focus while progressively towards the edges are sharp.

Don't think this is normal, but just to ask here to get your opinions and how to correct this. Thank you.

PS: Posted the same thing on Photo.net to get their inputs as well.

 

[DoveVadar]

Got myself a 110mm TCC (early FE) to be used on a 203FE. At close up and wide open, it focus alright. But when rack up to infinity, again at f2, the center of the image is out of focus while progressively towards the edges are sharp.

Don't think this is normal, but just to ask here to get your opinions and how to correct this. Thank you.

PS: Posted the same thing on Photo.net to get their inputs as well.

hmm.. seems like your screen is off, not your lens. what focusing screen are you using on it?

 

[Dream Merchant]

Assuming no gross manufacturing errors, the only thing I can think of, if ALL the corners are progressively sharp and the center blur, is a bowed focusing screen, unless it's possible for a mirror to get bowed as well.

Anything else involving mis-alignment will usually cause uneven focus along or towards one plane only, and not radially towards all corners.

 

[regit]

Thank you for the input guys. I don't think it would be the screen or mirror as the lens is rack up to infinity, with no attempt to focus at all.

One of the folks at Photo.net suggested that it may be a bulge in the film or the lens may be a case of mis-collimation. I'll run more test with a different lens and back when I get more light. Cheers!

 

[regit]

hmm.. seems like your screen is off, not your lens. what focusing screen are you using on it?

I'm using the stock screen that comes with the 203FE, the one with a circle indicating the metering area.