Ilford 500 head - anyone swap the green dichroic filter for a yellow one?

[Jeff Bannow]

I've got an Ilford 500 head mounted on my Durst L1200. I've heard talk of swapping out the green filter for a yellow one for better contrast control.

From Chris Woodhouse of RH Designs:

"The yellow/green thing is all about getting the maximum range out of modern papers. The Ilford MG head was designed for MG III paper. Paper has moved on since then and I found that the green filter was not soft enough to get the softest contrasts from Ilford and Agfa paper. I substituted for a standard yellow one from a colour head and extended my grade range. Of course, the downside is that you need to re-calibrate, but we include cal charts for the common papers. Agfa MCP and MCC is now Adox MCC and MCP."

Has anyone tried this yet? Can you recommend a source for the yellow dichroic glass?

 

[Ian C]

Have you considered simply leaving all filters set to zero and using below-the-lens VC filters?

In this way you get the full contrast correction the filters and paper can deliver.

It’s a simple solution and works well on the dichroic enlargers I’ve use with this idea.

 

[Jeff Bannow]

Have you considered simply leaving all filters set to zero and using below-the-lens VC filters?

Thanks, but that wouldn't work with my controller, which split grades right in the head during exposure. It works fine now with the green filter, just thinking about tinkering a bit with it.

 

[ic-racer]

just thinking about tinkering a bit with it.

Don't

Seriously, have you checked it against the softest ILFORD filter you own? You have a step wedge, right? See how many gray bands you get with the Green filter in the head. Then see how many gray bands you get with white light from the head and the softest ILFORD filter you own laying over the test strip. Develop the two test strips in the tray at the same time.

 

[Jeff Bannow]

Don't

Seriously, have you checked it against the softest ILFORD filter you own? You have a step wedge, right? See how many gray bands you get with the Green filter in the head. Then see how many gray bands you get with white light from the head and the softest ILFORD filter you own laying over the test strip. Develop the two test strips in the tray at the same time.

Small problem - you can't get white light from the head.

I do have a step wedge and some ilford filters though.

 

[ic-racer]

Actually since you just want to see if you are getting "all that the paper will give" you can do the test with the ILFORD 00 filter under another enlarger.

 

[Jeff Bannow]

Now that I could do.

 

[ic-racer]

Ilford literature says that with MG paper, filter "00" should give an ISO(R) of 180 that should be about 12 gray steps not counting the "just black" and "just white" steps (assuming a common 21 step wedge).

 

[ic-racer]

Make sure it is a diffusion head if you are going to use a second one to test with the 00 filter. A condenser head will give different results and you want to compare against the Ilford head, which is diffusion.

Only light color of the enlarger will have an effect in this test of the paper. This is a contact print of the step wedge.

 

[Jeff Bannow]

OK, done. Now, how do I interpret the results? They don't have the same # of "stops". One of them has 1-2 stops less range, if that makes any sense.

 

[ic-racer]

OK, done. Now, how do I interpret the results? They don't have the same # of "stops". One of them has 1-2 stops less range, if that makes any sense.

If it is the ILFORD 500 head that has less range, then, indeed the green filter does not give the least contrast available.