[LargeFormat] Winter oil change

[philip lambert]

Cautionary tale:

I am replacing my 180mm TeleArton f5.6 with a 180mm Symmar as I no longer
need the short back focus and welcome the wider field of the Symmar.
However this came in a Synchro-Compur shutter that is slow, sometimes by
half a stop or more  and some speeds aren't the same twice in succession. I
put the  shutter for three hours in a petrol-vapour atmosphere  (having
taken the glass out). Hitherto this has softened up coagulated lubricant to
good effect but on this occasion had adverse results.
The speeds 1sec 1/2sec, 1/5 sec stopped working or were unpredictable.
Higher speeds worked but 1/100 was timed at 1/90 to 1/120, 1/200 was nearer
to 1/125 and 1/400 was approx 1/200 or worse.

These odd effects were temporary, as a day later as the slow speeds were
working again and most speeds were more or less a half stop slow. I can live
with this if speeds are consistent by putting a small correction table or
note  on the lensboard. Over-exposure doesn't bother me on negative film
(although it would on 'chromes) but unpredictable speeds are a bother.  I
suppose a professional overhaul would be good. Regrettably the firm I used
for my 203mm Ektar didn't do much of a job.  Philip