250R with 2x converter

[bscott]

I have a 250 r lens that I use with a 2x converter on an R8 body. The problem is that with the converter the center of the focusing area is difficult to see correctly for sharp focus. The converter has a black and clear center with the focus screen around the center. I am always trying to focus on the area around the center since the center is so difficult to see the subject and get in focus. Is this the nature of the equipment or is there something I more that I need to know? Would a different converter work?

[wildlightphoto]

A different viewscreen would work better. I suggest plain matte or matte with grid lines. The split-image focussing aid and microprisms become ineffective at lens apertures smaller than f/5.6. The 250mm lens with 2x extender has an effective maximum aperture of f/8.

[stuny]

Bill -

What you describe is fairly universal on cameras with the split image center when used with very slow lenses. Before changing your viewscreen I sugest trying this: When you experience the half blackout move your eye slightly in relation to the viewfinder, so that you're looking into the viewfinder from a very slightly different position. Try moving it around a bit. Most of the time you'll find a position where you'll be able to see through both sides of the split image at one time.

[bscott]

Thanks to both of you for the helpful suggestions. At least I have an idea of what might work best for me.

[jaapv]

A full matte screen is by far the best option for long lenses and macro. The trick is to "walk" the plane of focus. Look at the surface the subject is sitting on and move the focus to see it move from back to front and vica-versa, to get it just where you want it.

[bscott]

Any suggestions on how I can purchase a full matt screen for the R8? Is it difficult to install?

[jaapv]

It is a standard accessory, which you can order. Installing is easy, see the manual. There is a mini-manual included with the matte screen, in case you don't have the one that goes with the camera. The tweezers and a cleaning brush come with the screen too.