cyrus
7-May-2007, 10:32
Since I've been studying photogravure I am used to the sort of vacuum frame that has the glass plate one on top. It is used to shoot copper plates using UV. The glass sandwiches a fine mesh aquatint screen and the positive over a piece of sensitized gelatin sheet. I've now bought a plate-making machine which has a vacuum frame too.
Can this work for enlargers when printing photos too or will the glass muck things up (refraction, reflection etc)?
I have seen some vac easels that don't have a glass plate on top which rely solely on the sucking of the vacuum pump to hold the paper down flat.
Seems to me that if the glass doesn't interfere with enlargement, then you can just use the glass to hold the paper down and don't really need a vacuum easel when making enlargement. The real purpose of a vacuum easel is to hold the paper down flat, not to ensure a tight contact with anything. Thus, there's no real advantage to having a vacuum easel if you can just place use a sheet of glass over the paper to hold it down during the exposure.
After all, a very high-pressure surface to surface contact is necessary when shooting a fine aquatint screen that will be etched on a copper plate, but just the weight of the glass plate should be sufficient for hold photo paper flat.
Can this work for enlargers when printing photos too or will the glass muck things up (refraction, reflection etc)?
I have seen some vac easels that don't have a glass plate on top which rely solely on the sucking of the vacuum pump to hold the paper down flat.
Seems to me that if the glass doesn't interfere with enlargement, then you can just use the glass to hold the paper down and don't really need a vacuum easel when making enlargement. The real purpose of a vacuum easel is to hold the paper down flat, not to ensure a tight contact with anything. Thus, there's no real advantage to having a vacuum easel if you can just place use a sheet of glass over the paper to hold it down during the exposure.
After all, a very high-pressure surface to surface contact is necessary when shooting a fine aquatint screen that will be etched on a copper plate, but just the weight of the glass plate should be sufficient for hold photo paper flat.