DeVere 504 cathomag head & VC adjustment

[philldresser]

I have a Devere 504 with a Cathomag colour head.

After consulting the Ilford multigrade IV leaflet (enclosed with the paper) in respect to colour head settings to achieve various grades, I found myself wondering which scale to use.

Firstly there is a general grouping as to the manufactuer of the enlarger. No problem here as DeVere is listed. Then there is a series of scales whether you want to use single or dual filters to attain the relevant grade. However both of the scales (single and dual) have values above the range of my colour adjustment.

My scales go to 170 on C,M and Y. These scales apply to other manufactuers in the ilford brochure.

So my questions are:
1. Does anyone use the same setup and if so what scale do you use
2. Which scale should I be using and
3. Is there a test that I can do to calibrate and not use the Ilford guidelines at all

Thanks

Phill

 

[Chris Lee]

Phill,

Glad to see you got it in the car!

I came across the same problem with the filters. I just ignore the scales on this and other colour heads. I simply increase magenta to add contrast or yellow to decrease contrast. This does mean that the exposures will change with the contrast, but I tend to find that even with the ilford mg filters.

I also found the 504 prints flat, and on old negs that print fine on grade 2 I have to have the magenta up to around 60 to get a comparable print.

My 504 is now heavily adapted When the transformer and timer packed up I couldnt source another cheaply, so it is now rewired with a different light source.

 

[philldresser]

Phill,

Glad to see you got it in the car!.

Chris

Yes I got it in the car, the 40 odd boxes of paper, a 20x16 easel,the 9 processing trays upto 20x16 and basically his whole darkroom. His face was priceless when I said that I had to get the wife and 2 kids in as well. Fortunately it all went quite smoothly.

Now I am trying to convince the better half how important it is to have a 'permanent' darkroom

I came across the same problem with the filters. I just ignore the scales on this and other colour heads. I simply increase magenta to add contrast or yellow to decrease contrast. This does mean that the exposures will change with the contrast, but I tend to find that even with the ilford mg filters.

I also found the 504 prints flat, and on old negs that print fine on grade 2 I have to have the magenta up to around 60 to get a comparable print.

My 504 is now heavily adapted When the transformer and timer packed up I couldnt source another cheaply, so it is now rewired with a different light source

I printed some shots last night but was very disappointed with the contrast control and assumed I was reading the wrong scale.

Phill

 

[Bob Carnie]

Hi Phil
One practical way to solve your problem is to send a negative to a friend ,and have the negative printed to match in all five grades using the 0-5 filters.
You then on your enlarger match the prints and record the magenta or yellow settings you used to match the prints. This will give you starting points for filtration.
If you don't have anyone locally able to do this , you can send me the negative and I will make 5 prints for you.
As stated above this is a very basic method , but a way to get you in the ballpark for filtration starting points.
Bob Carnie

 

[Les McLean]

Phil

If you are prepared to spend a little time and paper you might try the following to arrive at magenta and yellow contrast settings that suit your taste. The prints you make need only to be small, 5 x 4 will do so you'll get 4 from an 8 x 10 sheet of paper. You will need the little Ilford gizmo that you lay on the base board to read the light value it's called something like EM10.

Select a negative that shows a good range of tones and make a print using no filtration, the equivalent to grade 2. Make the best print you can but the most important factor is to get the highlight exactly where you want it to be. Make a note of the exposure time for the idea is to keep this constant. Dial in 10 yellow filtration and use the little gizmo to read the light value, it works on a three light system where the centre light shows the value to be correct. Leave the exposure time as it was for the first print and adjust the apperture to get the correct exposure. Continue this procedure but change the yellow filtration by 10 units for each print. You can carry on and do it until the yellow setting is at the maximum allowed by the enlarger, my suggestion is that you need go no further than about 80 yellow. Do the same for the magenta setting but this time test it in 10 unit steps right to the maximum setting on the enlarger. make a note of the filtration colour and value on the back of each print.

When the prints are dry lay them out in sequence from 0 filtration to the highest value in each colour keeping the magenta separate from the yellow. You then inspect them and select the soft and then hard contrast that you prefer. In effect you are selecting your own grade system for the paper. It is time consuming but you only need do it once.

Many years ago when Sterling VC paper was introduced into the UK the manufacturer gave no indication of filtration values and the importer asked me to help them produce some indication, this is how I did it.

If you do it please let us know how you get on. If you get frustrated when doing it blame me and I'll buy you a pint when we meet in October.

 

[Ed Sukach]

Many moons ago, I wrestled with the Dichroic Head settings in my Omega D5500 trying to get them "right" for printing Ilford VC papers. The values given in the enclosed Ilford data sheets did not seem to be useful - at all.
The gelatin Ilford MG Filters worked - *very* well.

I decided to analyze the gelatin filters 0 - 5, using the ColorStar 3000 (that took some thought), and discovered that they were *not* pure yellow or pure magenta; each transmitted a combination of yellow and magenta.
I plotted contrast curves using this information. I can give you this information, but I don't think it will be of significant value; a LOT will depend on the particular system in your enlarger - the color temperature of your enlarging lamp ... etc.

I would try the gelatin filters - after that, it is a matter of analysis and/or trial and error.

 

[glbeas]

I decided to analyze the gelatin filters 0 - 5, using the ColorStar 3000 (that took some thought), and discovered that they were *not* pure yellow or pure magenta; each transmitted a combination of yellow and magenta.

Very practical! Not surprising this fact, I believe it's done to keep the exposure times more consistent when changing contrast filters. I've seen a website dedicated to calculating values for your own system using this mix of yellow and magenta, creating a neutral density of sorts to buffer the exposure time as the proportions change.