Making an Omega B66 into a point-source enlarger?

[eli griggs]

I have an Omega Pro B66 in great shape and I'm wondering if I can make this into a point-source machine, perhaps one that uses an automotive LED?

I don't want to make a permanent change to the tool, it's a good one and I won't chance damaging it, but I am curious and want to see for myself what point-source can do.

Has anyone here done this or point me to a design or site that can walk me through the process?

Cheers

 

[eli griggs]

I could also use a pdf of the B66 manual if anyone knows where to download one or can email it to me.

Eli

 

[Claire Senft]

To make a point light source will require a couple of different things. A clear bulb with a very small filament. A transformer to supply voltage to the bulb. A means of centering the bulb over the condensers. A means a raising and lowering the bulb.

Ideally you will want to position the bulb so that it just fills the enlarging lens when it has been positioned and focussed for printing. This requires the ability to raise and lower the bulb. As you change magnification you will find that the bulb will require lowering or raising.

The bulbs that are used for point light source work have very small filaments...in the range of 1/4 inch... and are driven by a transformer at low voltages...12 to 24 volts systems are the most common. The enlarging lens is used wide open. To control exposure it is very helpful to be able to lower the voltage of the bulb to not get overly short exposure times.

 

[eli griggs]

Thank Claire. I don't believe centering and movement of the bulb will present too great a difficulty, so I suppose I should approach this by first taking a decision on which LED or bulb would be best suited to this machine and work out the electrics. Knowing that I can then build the adjustable lamp housing, or at least that's what I'm thinking now. I wonder how much vertical movement I'll need for small/medium format?

Do you have a suggestion as to a LED/bulb and perhaps transformer combination? I wonder if Radio Shack has a suitable transformer listed online?

The lenses I have available for 35mm/6x6 are only average and I want to try Nikons, the 50 2.8 and 80mm on my other machines. Does anyone have an opinion on these or any other average priced glass for point source enlarging?

I should also ask, am I overlooking anything critical or no?

Cheers