DIY Focusing Screen Focusing Aid

[marius cramer]

Hello fellow film shooters!
My ground glass for my ETRsi is quite scratched and dark so I went out and searched for some screens. The obvious ones (Maxwell; Beattie; Oleson) are to expensive for me (I know those prices are fair, I just cannot afford them). I found a screen in the bay which is the perfect size but is just matte without any focusing aid so my question is: Is there any way you could make these aids (preferrebly split image) yourself?
Thanks guys,
marius

 

[btaylor]

Maybe try the plain groundglass, you might like it. My favorite focusing screen on my OM-1 is the plain groundglass. I got it to use slow telephoto lenses but found I preferred it for all around use. I find it helps me reduce compositional distraction without any marks attracting my attention.

 

[Dan Daniel]

Sure, you could make your own split image circle. Simply take some optically clear plastic and make two wedges about .8mm thick, then machine a matching recess at the center of your plastic matte screen and install the wedges in opposite orientation so that point where the wedges are at the same height matches the matte screen surface within 0.01mm. Hard to describe but I can provide a diagram if you'd like.

 

[wiltw]

A genuine ETRSi plain ground glass is only $21, and with split image is $38 on ebay. I use the ETRSi screen with split image with microprism collar and crop indicator for 135 format (as a visual aid to level horizons!) and have never found the ETR screen at all 'dark'. The use of screens like the Beattie brighten the viewfinder, but I found that while a brighter Beattie viewfinder did not make focus accuracy suffer it did mess up metering prism accuracy. (Mr. Beattie was so kind as to lend me a Brightscreen to assess brightness and accuracy questions over 20 years ago.)

 

[marius cramer]

Hard to describe but I can provide a diagram if you'd like.

That would be neat!

 

[marius cramer]

wiltw: Unfortunately, there are no screens on eBay in Germany or any EU country for that matter. I don't want to pay massive shipping costs or import fees if I buy from the US.

 

[marius cramer]

btaylor: I found a ground glass on eBay which is for large format, I will cut it to the needed size and can get 2 screens out of it. Maybe I will try to DIY a focusing aid on one and leave the other blank. Thank you for your reply!