Originally Posted by wogster
The opemus 3 came out in 1969, and was made until 1975, when the 4 was prouduced, it was the last opemus without a filter draw, with the 4 also came the MG and colour head as they expanded the range, they were all so well made that they last forever.
Didn't know the history, makes sense though, before the 70's almost nobody did colour at home, and MG B&W paper wasn't around yet, so filter drawers were not really needed. An enlarger is so mechanically simple that they should last pretty much forever, the colour ones with built in filters, maybe not, I don't know how the filters actually work on those. About the only reason to replace one is if the manufacturer used a proprietary bulb that is no longer available, and altering it to use a different bulb isn't possible.
Originally Posted by R.Gould
I used to print with an Opemus II and I did print colour and Multigrade with it. I used to place the filters atop the condenser. The head bayonets off easily. Make sure you use a UV filter on the top and be careful they don't melt under the heat of the bulb. So it is possible, it just takes a little lateral thinking to achieve it. :-)
The home processing of color photography in Czechoslovakia was possible since 50ties. For older Opemus enlargers (as Opemus 6x6, Opemus II, Opemus III) was produced special adapter, called Meocolor. Meocolor was inserted between bulb and condensor. At the top of adapter was inserted IR filter, color filters were inserted into the slot. Subtractive filters were from glass and coloured gelatine in sets with 12 pcs for cyan, magenta and yellow color. With this filters you could change every color with 5% increments. The filters was made by Agfa, ORWO and by Meopta (Subtracolor correction filters). The first color head produced by Meopta was Meochrom and was produced for Opemus 5 enlarger. Color III and Color IV was newer color heads for enlargers Opemus 6,7 and Magnifax 4. Glass - gelatine filters weren´t very well, because their colour wasn´t stable and they faded with years. It wasn´t recomended to buy older used filter for this reason.
The second method was additive color mixing, when you can use only three filter - yellow, red and green and you expose paper three times. This was very cheap, you could insert filter between lens and paper, but now is this method obsolete.