Dichro Head on LPL 4x5 Enlagers. Is it Constant Exposure?

Hi,

simple question I guess. I have an LPL 4x5 enlarger with a Dichro head. I lust for a VCCE head but at around $1,000 I can do without one, and live with the Dichro.
So, the question I have is: Do I have to adjust exposure when using filtration on the Dichro head, or is it constant exposure?

claudio

https://www.ilfordphoto.com/technical-downloads/paper/ go to this page and download the document titled "Contrast Control .... " and it will give you colorhead settings for using a single color and requiring exposure change, or using a combination of M and Y to approximate VCCE. LPL colorheads follow the "Kodak" column on page 3.

I use the Kodak column on that chart and the exposure times are fairly consistent up to about grade 3.5. Higher contrast sometimes needs a bit of extra exposure.

I would love a VCCE head too! I don't do any color printing.

Any VCCE exposure system is going to be approximate, since when you change contrast you might often find the entire print needs to be somewhat lighter or darker. And different patper manufacturers probably have slightly different responses to the colors. But, the VCCE heads are supposed to be constant, and you can calibrate a color head for constant exposure. Note that when you do this, you are dialing in extra filtration to cause neutral density, so you don't get the shortest exposure possible for a given contrast.

If you keep the filters clean and undamaged, below the lens filters from Ilford and the like are calibrated for VCCE on the lowest filters, and double exposure on the higher contrast filters. It's probably easier than calibrating the dichroic filter settings and may be cheaper, too. But it is certainly possible to calibrate filter settings for virtually VCCE.

Before I got a VCCE filter module for my Saunders, I had the Dicro head. I split print so it was either max magenta or max yellow. The biggest problem with the Saunders heads is they don't illuminate unless the enlarger light is on. I used to have a little tiny red flashlight that I used to change settings on the Dichro head. PITA. I ended up using below the lens filters just to save time turning the dang dials.

If you haven't figured it out yet, I suggest you just pick up some Ilford below the lens filters and make your life easier.

As far as I know, time always changes, when you change filters. No matter what kind of head you use.
I use a split grade unit on my LPL7452 and when I change the measured filtering on the control unit, the time automatically changes with it.
Suppose it has something to do with reaching maximum black, which takes more time when you use more yellow/less magenta.
Differences are small, so you won’t always notice it in the print, but become bigger when the difference between the grades become bigger, like going from 2 to 4.
Regards,
Frank

Thank you everybody, a lot of good information here. I guess the VCCE head is not the silver bullet that I thought it was.

claudio

Patrick Robert James said:

Before I got a VCCE filter module for my Saunders, I had the Dicro head. I split print so it was either max magenta or max yellow. The biggest problem with the Saunders heads is they don't illuminate unless the enlarger light is on. I used to have a little tiny red flashlight that I used to change settings on the Dichro head. PITA. I ended up using below the lens filters just to save time turning the dang dials.

If you haven't figured it out yet, I suggest you just pick up some Ilford below the lens filters and make your life easier.

Click to expand...

There may be a small light bulb in the dichroic head that needs to be replace so that you can set the enlarger without a flashlight.

CCLA said:

Thank you everybody, a lot of good information here. I guess the VCCE head is not the silver bullet that I thought it was.

claudio

Click to expand...

I use the 4550 VCCE, it is a dream to use, having also used the alternatives I WOULD call it a silver bullet.

Just to be clear about how it is used:

there is a single dial for contrast, 00 to 5 with half steps identified

exposure is constant for all settings, the change that occurs for grades 3.5 and higher is compensated automatically, it requires no thought

Sirius Glass said:

There may be a small light bulb in the dichroic head that needs to be replace so that you can set the enlarger without a flashlight.

Click to expand...

The LPL head is modular, and is 3 modules, the mixing box, the lamp assembly and the filtering module, only the lamp section has power. The scales are only illuminated when the main lamp is on.
Perhaps this is one of the few flaws for the machine. It probably wouldn't be difficult to hack a battery powered LED into the filtration module to light the scales when the main lamp is off, if one were so inclined, and had the stuff to do it.

I use a small red light to read the settings if I need to and can't turn the lamp on for some reason. It's not been a particular issue for me, but I can see where other's mileage may vary. FWIW, I agree with tedr1, I like working with the VCC head, and find it much more convenient that looking up magenta and yellow filter settings.
In some respects neither color heads or VC heads lend themselves to split grade printing since you're only using the extremes of the filtration. But I still prefer the built-in filtration to juggling discrete filters.

I use an LPL 4500 with the VCCE head. Love it. My life is so much easier compared to when I used an enlarger with dichoric head and yellow/magenta dials. When I had the dichroic head, I had to make new test strips any time I changed contrast, now I don't. A time saver and a luxury.

Dale

I would agree that a VCCE head is a lot easier than using a color head approach, but the current new prices seem astronomical to me--the Ilford filter set is an affordable approach. I was able to pick up a used VCCE module for my 4500-II at a rational price a few years ago. I'd like to find a similar bargain for the 670 (6600) version, too.

Yes not surprisingly the VCCE heads seem to fetch a premium, the other heads seem to be much lower in price. I offered to KHB my surplus Dichro color head, in mint condition, and the offer was declined.

tedr1 said:

Yes not surprisingly the VCCE heads seem to fetch a premium, the other heads seem to be much lower in price. I offered to KHB my surplus Dichro color head, in mint condition, and the offer was declined.

Click to expand...

I sold mine on ebay for €68 just a few months ago.
Regards,
Frank

Frank53 said:

I sold mine on ebay for €68 just a few months ago.
Regards,
Frank

Click to expand...

By 'heads' I assume we are talking about the head modules available to the 4x5 enlargers. As Frank points out, they can had affordably with luck and diligence.
I've seen a couple 4x5 LPL enlargers come up for sale locally in the last year. Though I've noticed enlargers in general come up in price drastically in the last couple of years.
I recall that the VCCE modules for the 4500II and the XLG models are interchangeable. Other than color difference black vs gray, there should be no difference. So keep a lookout for either module.
Along with a Heiland Splitgrade head module, I have an a VCCE module from an XLG mounted on my 4500II. Both are great.