Multigrade IV without filter

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ATIPPETT - 29 May 2004 05:50 GMT

Recently I was distracted during a printing session and forgot to use a filter
when I exposed the paper. Not realizing what I had done I contiuned and
printed the print as if I had used a filter. My results are fine, appear to be
midrange, but what is the theoretical grade of my print? Is there a
predictible grade or are this other variables that I would have to factor in?

Alan Tippett

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Donald Qualls - 29 May 2004 07:03 GMT

> Recently I was distracted during a printing session and forgot to use a filter
> when I exposed the paper. Not realizing what I had done I contiuned and
> printed the print as if I had used a filter. My results are fine, appear to be
> midrange, but what is the theoretical grade of my print? Is there a
> predictible grade or are this other variables that I would have to factor in?

It varies slightly from one paper to another (and with different
developers, of course), but for most variable contrast papers no filter
is approximately the same as a grade 2 to 2 1/2 filter, but with much
shorter exposure.

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Donald Qualls, aka The Silent Observer
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Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.

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Severi Salminen - 29 May 2004 10:40 GMT

I wondered the same thing once and asked directly from Ilford:

My questions:

It is stated that the contrast of MGIV unfiltered is 2 (in the
documentation from Ilford's site)

1. How much is this figure affected by the type and age of enlarger
lamp, if any?

2. Does the type and age of the lamp affect the contrast only when _not_
using filters, or does the lamp also have an influence on ALL filters
and their contrast range? And how much might this variation be?

3. If the lamp has no effect of contrast: are there any differences in
any situations between using a filter #2 and not using any filter
(besides paper speed)?

Answers:

1. The contrast given without a filter can vary considerably, although
with tungsten light sources, the variance is rarely more than 1/2 grade.
Some cold light heads can give an unfiltered contrast of as high as
grade 4, although most are between 3 and 3 1/2.

2. The different light colors will still have an effect with the filters
in place, although the effect will be diminished by the filters. In the
case of tungsten light sources, the effect will usually be small enough
to be ignored, although with a very old or new bulb, or in the case of
voltage fluctuations, you may notice a larger shift. With cold light
heads, the result may be as much as a 1 1/2 grade differential, and
will probably not be consistent across the entire range.

3. With a standard (ideal) tungsten bulb, there will be no difference
between using a #2 filter and using no filter, other than the paper
speed. However, I would recommend using the filter anyway, so that you
can take advantage of the speed matching of the filters.

Regards,
David Carper
ILFORD Technical Service

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Tzortzakakis Dimitrios - 29 May 2004 13:13 GMT

With a condenser enlarger, it's 2 1/2.

--
Dimitris Tzortzakakis,Iraklion Crete,Greece
Analogue technology rules-digital sucks
http://www.patriko-kreta.com
dimtzort AT otenet DOT gr the return adress is corrupted

> Recently I was distracted during a printing session and forgot to use a filter
> when I exposed the paper. Not realizing what I had done I contiuned and
[quoted text clipped - 3 lines]
>
> Alan Tippett

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