I recently had a Supermatic 800 shutter CLA'd by Paul Ebel. It was his opinion that the fast shutter speeds never did, in fact, reach those speeds. Now the shutter is accurate to 1/100. Then 1/200 is also 1/100. 1/400 is actually 1/200 and 1/800 is actually 1/400, which is pretty good. I just need to remember that when using.