A New Focusing Screen

My 40 year old medium format film camera had a simple matte focusing screen on it which made focusing a bit difficult.  This matte screen simply showed the scene and you would have to sort of guess what was the best focus.  There was nothing to help you actually see if the image is in perfect focus.  Using only your eyes makes it easy to slightly miss focus especially with older eyes like mine.  I knew I wanted to replace this focusing screen with a better one.

The main problem with wanting to replace anything on this camera is that this is a 40 year old film camera that has been out of production for decades.  Finding parts can be difficult.  Regardless, I went on a search for the type of focusing screen I wanted.  

I wanted a screen with a split prism in the very center, a micro-prism collar surrounding the split prism, and a matte ground glass field.  These can be difficult to find now but I happened to find one in Japan so I purchased it and had it shipped to me.  

Below is the plain matte screen that I wanted to replace (after I removed it from the camera).  The one good thing about this matte screen is that it had guide lines etched into it but I could live without the lines.  I needed a more accurate way of focusing.

Replacing the focusing screen is a quick and easy task.  You simply slide a tiny toggle switch on the inside of the lens mount from one side to the other.  The focusing screen then pops out of its frame.  Then, with a pair of tweezers, you carefully lift the focusing screen out through the lens mount.  It is sort of like playing the old game of "Operation". 

What is slightly more difficult is carefully placing the new focusing screen into the camera body through the lens mount and perfectly onto the frame that holds the focusing screen.  After getting it in place, you simply slide that toggle switch back to its original position.  Honestly, it takes less time to replace the screen than it does to type what to do as I did here!

Here is a photo, through the viewfinder, of the new focusing screen.  When the image is not in focus, that split prism in the center shows vertical lines broken and shifted left and right.  The micro-prism collar around the split prism is very pixelated and the rest of the matte screen field is shown out of focus.  This photo, below, shows one of our living room lamps out of focus and it is now very easy to see that the image is grossly out of focus...

When the image is in perfect focus, the vertical line that was shifted left and right will now be shown as one single, straight line.  Also, the micro-prism collar is no longer pixelated and the matte screen field is showing exactly what will be seen in the photo.  These two optical aids makes focusing much more accurate and far easier!  Here, below, is a view through the viewfinder showing this same lamp in focus...

I practiced focusing using two different lenses and this new focusing screen makes focusing easier, faster and more accurate.  This was definitely a much needed quick and easy upgrade.

A bit of an odd thing about this big old medium format camera is that the way to attach a strap is very different than today's cameras.  These big old cameras had a stud on each side of the camera meant to hold a very specific clip.  The size of these studs varied by camera manufacturer which makes things a bit more convoluted.  I found some clips made specifically for my Pentax 645 and the new clip on one side of the camera is shown below.  Now I can have a strap secured to this big old camera.

Below is a photo of the camera with the strap connected...  

It is nice having a high quality strap on this camera now but the best upgrade so far has been the new focusing screen.  This makes a tremendous difference!