Ilford Warmtone vs Classic FB Speed

[Peter Lewin]

I have been using Ilford Classic FB for all my serious printing, but just ordered a 10 sheet batch of Warmtone to see if I like it. I have been unable to find any speed comparison or data for Warmtone vs Classic. If I have my time/f-stop/filtration for a negative on Classic, can I use that directly to make an equivalent print on Warmtone, or do I have to start from scratch with the Warmtone paper, i.e. a new test strip and so on? Thanks in advance for any advice.

[Sal Santamaura]

I have been using Ilford Classic FB for all my serious printing, but just ordered a 10 sheet batch of Warmtone to see if I like it. I have been unable to find any speed comparison or data for Warmtone vs Classic. If I have my time/f-stop/filtration for a negative on Classic, can I use that directly to make an equivalent print on Warmtone, or do I have to start from scratch with the Warmtone paper, i.e. a new test strip and so on? Thanks in advance for any advice.Per HARMAN's technical information, Classic


https://www.ilfordphoto.com/amfile/file/download/file_id/1921/product_id/733/

has an ISO paper speed of 500, while Warmtone


https://www.ilfordphoto.com/amfile/file/download/file_id/1945/product_id/739/

is 200. Therefore, expose Warmtone 1-1/3 stops more than what you've been using with Classic.

Note that, due to varying characteristics of the two papers, this will only provide a starting point. Given their different curve shapes, test strips / trial prints will undoubtedly be necessary to obtain a Warmtone print you find as good as the refined ones you've probably made on Classic.

[Oren Grad]

Ah, Sal beat me to it in digging up the data sheets.

In my experience working with both papers, Warmtone is indeed quite a bit slower. It also has a different curve shape, so you can't assume that a fixed compensation factor will yield optimal results when moving from one paper to the other - or even that a given negative will necessarily "work" on both papers.

[NER]

I have been using Ilford Classic FB for all my serious printing, but just ordered a 10 sheet batch of Warmtone to see if I like it. I have been unable to find any speed comparison or data for Warmtone vs Classic. If I have my time/f-stop/filtration for a negative on Classic, can I use that directly to make an equivalent print on Warmtone, or do I have to start from scratch with the Warmtone paper, i.e. a new test strip and so on? Thanks in advance for any advice.

https://www.ilfordphoto.com/amfile/file/download/file_id/1945/product_id/739/
https://www.ilfordphoto.com/amfile/file/download/file_id/1921/product_id/733/

N. Riley
http://normanrileyphotography.com

[locutus]

Stupid question:

do ISO paper speeds work the same as film ISO's ? I realise that ISO 100 paper and ISO 100 film have different sensitivities and that's not what i mean to ask..

Does 2 seconds at ISO100 give the same exposure as 1 second on ISO200 with paper?

[Taija71A]

... Does 2 seconds at ISO100 give the same exposure as 1 second on ISO200 with paper?

'Within Reason' -- Yes.
*There of course... Are always exceptions to this rule.
--
But, you are correct...

The 'Slower' that your Paper is... The 'L o n g e r' your Exposure will need to be.
Thank-you!

[Peter Lewin]

Thanks everyone! When I went to Ilford's site I couldn't find the data sheets, and your comments about the different curves are very useful.

[JMO]

For the OP, that little folded brochure that Ilford provides inside each box of their B&W paper includes charts on the ISO speed of most (or all?) of their papers - FB and RC. Check those and the accompanying discussion out.

[interneg]

Thanks everyone! When I went to Ilford's site I couldn't find the data sheets, and your comments about the different curves are very useful.

Their new website has them under "downloadable information" if you scroll down the product's page a bit.

Watch out for the dry-down on MGWT - it's more than on the classic & cooltone.

[Mark Sampson]

Someone more experienced than I recently explained that warm-tone papers are always slower than cold-tone papers, due to the laws of physics. And now I've forgotten why... perhaps because it's the smaller AgX crystals (that make the tone 'warm') are less sensitive to light? In any case, my own experience says every warm tone paper I've ever tried was slower than my usual cold tone papers.

[interneg]

Someone more experienced than I recently explained that warm-tone papers are always slower than cold-tone papers, due to the laws of physics. And now I've forgotten why... perhaps because it's the smaller AgX crystals (that make the tone 'warm') are less sensitive to light? In any case, my own experience says every warm tone paper I've ever tried was slower than my usual cold tone papers.

You're essentially correct that it has to do with the size of the grains & smaller grains capture less light than big ones. On the other hand, those smaller grains develop faster. In more traditional papers: warmer tone = slower paper speed, faster developing time; colder tone = faster speed, longer developing time. MGWT doesn't quite comply with that - it has a longer emergence time that's generally more in line with the lower chloride content, more 'neutral' tone papers & this more than likely has to do with the use of more complex emulsion technologies in its manufacture which probably allow tight control of grain size & thus 'warmth' of the final emulsion. It's a great paper - and the ART300 even more so.