ilford 500h head with yellow & magenta filter, why not green & blue?

[ballisticone]

hello guys,

my new enlarger arrived which is Durst 1200 with ilford 500h head,
before i order this unit, i have been doing some researched about it .

it normally come with green & blue light but mine has yellow & magenta,
after i search this website, i found out mine is the early version before
changing to the blue and green lights .

my question is, I find Blue & Green to be newer, should i replace it to be green & blue light ?
any benefit of Blue & Green ?

I found one guy on ebay selling the filter ,
https://www.ebay.com/itm/153429822457

Is it going to work on the unit?

Thank you very much.

 

[MattKing]

Your controller will almost certainly be matched to the filters you have, so I wouldn't switch if I were you.
I have that system as a backup to my 400 series system. As the 400 system just keeps working, I haven't switched.
When compared to a blue and green light version, a yellow plus magenta system may give you brighter light when in focus mode, but probably is at least slightly more limited when it comes to the maximum contrast available.

 

[ballisticone]

When compared to a blue and green light version, a yellow plus magenta system may give you brighter light when in focus mode, but probably is at least slightly more limited when it comes to the maximum contrast available.

Thanks for the answer Matt,

But what do you mean with the maximum contrast available ?
Doesn't the Blue & Green get to multigrade #5?

 

[MattKing]

Thanks for the answer Matt,

But what do you mean with the maximum contrast available ?
Doesn't the Blue & Green get to multigrade #5?

Yes.
But #5 on the later blue and green versions is probably slightly more contrast than #5 on the earlier magenta and yellow versions.
My 400 series is limited to #4, but if I need more I just add a below the lens filter.
By the way, those early models are quite old now. It would be best to check the controller for proper operation - particularly the switch pad - along with checking the fan in the head.

 

[koraks]

But #5 on the later blue and green versions is probably slightly more contrast than #5 on the earlier magenta and yellow versions.

This could be the case, but it's not necessarily so. When doing comparisons between y/m and b/g heads I did not see any visible differences with the materials I use. So it's a typical YMMV situation.

 

[ballisticone]

This could be the case, but it's not necessarily so. When doing comparisons between y/m and b/g heads I did not see any visible differences with the materials I use. So it's a typical YMMV situation.

Thank you very much.

 

[esearing]

I can get to 4.5-ish using 5.0 on my RH Analyzer with the Multigrade 500 head. If I remove the magenta filter and replace with below lens 5.0 I get a shift. Its not enough to warrant changes.

 

[cowanw]

Don't all of the incandescent systems start with white light and filter out colours as appropriate; I don't expect that there is reason to expect one set of blue green filters to be more or less efficient then a set of yellow magenta filters

 

[MattKing]

Don't all of the incandescent systems start with white light and filter out colours as appropriate; I don't expect that there is reason to expect one set of blue green filters to be more or less efficient then a set of yellow magenta filters

Dichroic filters use interference rather than "filtering out", so you are dealing with efficiencies.
But more importantly, filtering to blue and green matches the sensitivity of the paper more directly than filtering to magenta and yellow.

 

[cowanw]

Dichroic filters use interference rather than "filtering out", so you are dealing with efficiencies.
But more importantly, filtering to blue and green matches the sensitivity of the paper more directly than filtering to magenta and yellow.

a.Yes Dichroic, but both are that.
b. Are you saying a blue dichroic is better at removing green from the white light path than a magenta Dichroic. Or I suppose A magenta dichroic might remove some blue in addition to green.
PS and that seems to be the case.
https://qd-europe.com/de/en/product/optics/dichroic-filters-sets/dichroic-filters-and-sets

 

[MattKing]

As to b., a blue dichroic filter is better at reflecting only blue light, without reflecting green, then a magenta dichroic filter is.

 

[cowanw]

For some reason I thought that it was the colour they transmitted that counted in this application and that they reflect and destructively interfere with unwanted wavelengths.

 

[MattKing]

I think that when it comes to dichroic interference filters, using the terms reflect and transmit is probably inaccurate (and I apologize for doing so).
When you put a blue dichroic filter into the light path, you get very pure blue light.
And when you put a green dichroic filter into the light path, you get very pure green light.
And the papers respond to that.

 

[RalphLambrecht]

hello guys,

my new enlarger arrived which is Durst 1200 with ilford 500h head,
before i order this unit, i have been doing some researched about it .

it normally come with green & blue light but mine has yellow & magenta,
after i search this website, i found out mine is the early version before
changing to the blue and green lights .

my question is, I find Blue & Green to be newer, should i replace it to be green & blue light ?
any benefit of Blue & Green ?

I found one guy on ebay selling the filter ,
https://www.ebay.com/itm/153429822457

Is it going to work on the unit?

Thank you very much.

on Ilford paper green is indeed softer than yellow in my tests.