Ilford 500 - change bulb?

[Pavel+]

I have an Ilford 500H and like it very much except for the fact of shorter times on most papers than I wish for. If I remember corectly the first 500's came with two 150watt bulbs for a total of 300 watts and then it was changed to two 300 watt bulbs for a total of 600 watts - which is what I have.

I was going to get a one or two stop ND filter but would prefer to try changing the bulbs to 150 watt power out instead. As this is controlled by the cpu inside the controller - would that somehow mess things up or is it an option for me?
Does anyone know and any idea what kind of 150 bulb was fitted in the first run?

I'm getting some times on some paper in the 4-6 second range which is nuts.

I've been doing 6x7 mostly and with the medium format diffusion box. If I put the 4x5 size diffusion box, by my thinking I will not have any problems and the times should strech out a bit (or a lot?). Any advice in that regard?

Thanks!

 

[Tom Kershaw]

Pavel,

I've been printing with a Multigrade 500 head (600W) this afternoon and set the 100mm lens to f/16 to make the exposures easier to manage. 4x5" diffusion box with 645 negatives, 8x10 prints.

Tom

 

[StigHagen]

I've heard it is best to stick with the 300w bulbs (total 600w) to not loose blue light, which is important for the contrast calibration. What you can do is to take out the diffuser panels out of the mixing box and replace them with white perspex to get more time.

 

[Pavel+]

Thanks. I didn't think of an imballance in the light. I double checked and it does have the 600watt. I guess I will get a one stop ND filter as I had planned.

I measured the light difference between the correct medium format diffusion box and the oversized (for 6x7) 4x5 box and was surprised at how great it was. The medium format measured at 0.6 ev while the correct size box at the same settings was 2.0 ev. I may try printing with the larger, dimmer 4x5 box as see how that goes.

 

[StigHagen]

I measured the light difference between the correct medium format diffusion box and the oversized (for 6x7) 4x5 box and was surprised at how great it was. The medium format measured at 0.6 ev while the correct size box at the same settings was 2.0 ev. I may try printing with the larger, dimmer 4x5 box as see how that goes.

I use the 4x5" box only...also with medium format film. I don't bother changing boxes. No problem at all!

 

[ic-racer]

Like suggested, just use the 4x5 box.

 

[Jim Edmond]

I also just use the 4x5 box for everything.

 

[Tom Kershaw]

The smaller diffuser boxes might be useful when lith printing.

Tom

 

[Ian David]

I too just use the 4x5 box for everything.

Ian

 

[Andrew4x5]

Putting in a pair of 150W bulbs in a 600W head would work, and, being of equal wattage, they would not upset the green/blue balance. (Whereas putting 300W bulbs in a 300W head would overheat and damage the head). The bulb has to be 120V. There appear to be two bulbs: ESD and EZK, I'm not sure which is the correct one.
I once measured the relative intensities of the boxes. The 6x7 box is only half a stop brighter than the 4x5 one, and the the 35mm box is only twice as bright. So like the others, I only use the 4x5 box.

Andrew

 

[Ross Chambers]

Waddya do if the 4x5 box falls apart? A question I ask myself when I, too, use it all the time. Now the 35mm one can be replaced by the MF one or the 4x5, the MF by the 4x5, but what replaces the 4x5? As we DeVeristas know those diffusion boxes aren't easily obtained these days.

Just a paranoid thought ;-)

Ross

 

[Tom Kershaw]

Ross,

I was quoted 90 GBP for a replacement 4x5" diffusion box.

Tom

 

[StigHagen]

Putting in a pair of 150W bulbs in a 600W head would work, and, being of equal wattage, they would not upset the green/blue balance. (Whereas putting 300W bulbs in a 300W head would overheat and damage the head). The bulb has to be 120V. There appear to be two bulbs: ESD and EZK, I'm not sure which is the correct one.
I once measured the relative intensities of the boxes. The 6x7 box is only half a stop brighter than the 4x5 one, and the the 35mm box is only twice as bright. So like the others, I only use the 4x5 box.

Andrew

I've heard the intensity of the blue in the blue channel is more correct with 300w bulbs, as the light itself has blue color in it. In other words the 300 w bulbs are able to produce better contrast.