Most sensitive paper currently available?

Andy M · Jun 30, 2020

Hello All

Been a while since I last used the forum, so hope we are all okay during theses strange times?

Quick question - Has anyone done recent tests (or already knows) which currently available)black and white paper is the most sensitive (without pre flash) to light?

In other words which paper/s expose quickest?

Not worried about finish or type - simply interested in sensitivity and speed at this stage.

Any suggestions greatly appreciated.

Thanks in advance for your time and consideration - Andrew

removed account4 · Jun 30, 2020

Hi Andy M

To give you a base line. .. Regular Ilford RC MG is around ISO24 ... (relative to film )

MattKing · Jun 30, 2020

The new version of Ilford MG RC (sometimes referred to as MG V) is apparently faster than the MG IV RC.

Dj cooler martin · Jun 30, 2020

My guess would be Fomaspeed

ic-racer · Jun 30, 2020

No need to guess. Frequently the datasheet lists the ISO(P) speed. For example, unfiltered Multigrade FB is ISO(P)500 whereas the unfiltered Warmtone FB is ISO(P)200.
According to the Fomaspeed datasheet, it is slower than Ilford MG FB, at ISO(P)400.

AgX · Jun 30, 2020

Andy, is there a special reason you inquire on paper speed?

MattKing · Jun 30, 2020

I'm going to guess - paper negatives!

removed account4 · Jul 1, 2020

ic-racer said:
No need to guess. Frequently the datasheet lists the ISO(P) speed. For example, unfiltered Multigrade FB is ISO(P)500 whereas the unfiltered Warmtone FB is ISO(P)200.
According to the Fomaspeed datasheet, it is slower than Ilford MG FB, at ISO(P)400.

sadly these numbers the data sheets provide do not relate to ISOs relative to film ISOs.

===

On a different more fun note, Andy M,
If you have the time and interest you can make a paper emulsion in very little time
that will be even faster than conventional store bought paper emulsions. Last year I made a batch of
Silver-Gelatin-Chloro-Bromide-Emulsion, It was the Kevin Klein recipe listed on the Lightfarm website
( and in the book for sale on Blurb ). I made the mistake of adding a small amount of DEKTOL into the emulsion instead
of HYPO, and it basically turned the emulsion into something super fast. To give an example, Regular RC paper I make sun prints with ( photograms or contact print using the sun instead a darkroom ) and store bought paper takes sometimes IDK a minute or 2 to react to the sun, my emulsion was fast enough that I had to make contact prints through the back of the paper
and it reacted with the sun within 5-10 seconds of it being outside ...

like with everything
YMMV

have fun !
John

NB23 · Jul 1, 2020

I rate my paper at iso 2 or 3, and fine-tune from there.

AgX · Jul 1, 2020

Film-ISO you mean.

(as meanwhile we repeatedly also hinted at Paper-ISO)

Andy M · Jul 1, 2020

jnantz said:
Hi Andy M

To give you a base line. .. Regular Ilford RC MG is around ISO24 ... (relative to film )

Thanks for your advice Agx - appreciated A

Andy M · Jul 1, 2020

jnantz said:
sadly these numbers the data sheets provide do not relate to ISOs relative to film ISOs.

===

On a different more fun note, Andy M,
If you have the time and interest you can make a paper emulsion in very little time
that will be even faster than conventional store bought paper emulsions. Last year I made a batch of
Silver-Gelatin-Chloro-Bromide-Emulsion, It was the Kevin Klein recipe listed on the Lightfarm website
( and in the book for sale on Blurb ). I made the mistake of adding a small amount of DEKTOL into the emulsion instead
of HYPO, and it basically turned the emulsion into something super fast. To give an example, Regular RC paper I make sun prints with ( photograms or contact print using the sun instead a darkroom ) and store bought paper takes sometimes IDK a minute or 2 to react to the sun, my emulsion was fast enough that I had to make contact prints through the back of the paper
and it reacted with the sun within 5-10 seconds of it being outside ...

like with everything
YMMV

have fun !
John

John this sounds really interesting - Im going to give it a try - Any idea as to the amount of dektol you added? Was it the required amount for hypo, or did you mix the two? So many questions eh! - Ive already purchased the book. Many thanks for the heads up.

Andy M · Jul 1, 2020

AgX said:
Film-ISO you mean.

Yep ISO speed.

Andy M · Jul 1, 2020

NB23 said:
I rate my paper at iso 2 or 3, and fine-tune from there.

Thats roughly where Im at in terms of speed.

Andy M · Jul 1, 2020

MattKing said:
I'm going to guess - paper negatives!

Well its actually for making images of stars with - So yes a form of paper negative - hence my need for speed!

Andy M · Jul 1, 2020

MattKing said:
The new version of Ilford MG RC (sometimes referred to as MG V) is apparently faster than the MG IV RC.

This sounds good - the new version of RC - I haven't used it yet. - thanks for the tip.

Andy M · Jul 1, 2020

jnantz said:
Hi Andy M

To give you a base line. .. Regular Ilford RC MG is around ISO24 ... (relative to film )

Iwasnt are that Rc was faster than FB - 24 iso is fast for paper.

AgX · Jul 1, 2020

Andy M said:
Well its actually for making images of stars with - So yes a form of paper negative - hence my need for speed!

But then the spectral sensitization would be of importance too, as stars not only reflect blue light.

MattKing · Jul 1, 2020

AgX said:
Film-ISO you mean.

(as meanwhile we repeatedly also hinted at Paper-ISO)

Andy M said:
Yep ISO speed.

As AgX posted, the ISO speed standard for film is different than the ISO speed standard for paper - they are measured in different ways.
When you see people posting about using paper in camera, they are talking usually about the camera Exposure Index (EI) that they have arrived at experimentally, while using paper in an application it wasn't originally designed for.
Sort of like what you are doing.

removed account4 · Jul 1, 2020

AgX said:
But then the spectral sensitization would be of importance too, as stars not only reflect blue light.

!!!!

Andy M
you might look into a process called "hypering". or "hyper sensitizing". which involved fuming film over a warm bath of hydrogen peroxide. there is some sort of mythology around this process that it increases the relative film iso of iso 400 or 100 film to like 10,000. I have never done this, but maybe someone in-forum has experience or knowledge about this process to point you in the right direction. pan film will record starlight ... if you have your heart on paper as a media, I hate to bring modern tech into the picture but you can record the stars with a digital camera and make a film negative to contact print onto the paper

Andy M · Jul 10, 2020

jnantz said:
!!!!

Andy M
you might look into a process called "hypering". or "hyper sensitizing". which involved fuming film over a warm bath of hydrogen peroxide. there is some sort of mythology around this process that it increases the relative film iso of iso 400 or 100 film to like 10,000. I have never done this, but maybe someone in-forum has experience or knowledge about this process to point you in the right direction. pan film will record starlight ... if you have your heart on paper as a media, I hate to bring modern tech into the picture but you can record the stars with a digital camera and make a film negative to contact print onto the paper

Thats great - thanks for the heads up. Will give it a try.

pentaxuser · Jul 10, 2020

MattKing said:
As AgX posted, the ISO speed standard for film is different than the ISO speed standard for paper - they are measured in different ways.
When you see people posting about using paper in camera, they are talking usually about the camera Exposure Index (EI) that they have arrived at experimentally, while using paper in an application it wasn't originally designed for.
Sort of like what you are doing.

Matt I became confused when reading various posts. It would seem there is a consensus that in exposure terms paper ISO in film terms when used as a negative is about 2-3 but then a figure of 24 was mentioned in what appeared to be paper ISO in film terms eqivalent. So are we suggesting that when working out the correct exposure for a paper negative in a camera we should consider it to be the equivalent of a film sheet rated at ISO 24?

Finally what effect does the new MGV paper have on exposure as a paper negative?. It sounds as if this confers a doubling of speed in terms of its exposure as a paper negative. So does this raise the film speed equivalent in terms of its exposure in a camera to say ISO 6 or ISO 50?

No-one else seem confused so I assume I have missed some vital piece of information here that makes it plain that the true film negative exposure is in low single figures and not in the mid 20s

Thanks

pentaxuser

Ian Grant · Jul 10, 2020

jnantz said:
Hi Andy M

To give you a base line. .. Regular Ilford RC MG is around ISO24 ... (relative to film )

Actually Ilford state the ISO is 3 - 6 relative to film speeds.

Ilford make a very fast paper called Galerie FB/RC Digital Silver, this is designed for Durst Lambda printers and similar laser type printers, I'd guess it can be used in the converted Fuji Frontiere minilab printers Harman Direct use as well.

There was also Ilford Multigrade RC Express, I have a 12.7cm x 152m (5" x 500ft) roll, mine's actually marked Multigrade IV RC Express PF. It has a paper ISO P640. This paper is designed for short exposures in minilabs and machine printing and fast development 12 seconds at 40ºC, down to 46 seconds at 20ºC all times include transfer to next bath. Many B&W processors go straight from developer to fixer.

Ian

Andy M · Jul 10, 2020

pentaxuser said:
Matt I became confused when reading various posts. It would seem there is a consensus that in exposure terms paper ISO in film terms when used as a negative is about 2-3 but then a figure of 24 was mentioned in what appeared to be paper ISO in film terms eqivalent. So are we suggesting that when working out the correct exposure for a paper negative in a camera we should consider it to be the equivalent of a film sheet rated at ISO 24?

Finally what effect does the new MGV paper have on exposure as a paper negative?. It sounds as if this confers a doubling of speed in terms of its exposure as a paper negative. So does this raise the film speed equivalent in terms of its exposure in a camera to say ISO 6 or ISO 50?

No-one else seem confused so I assume I have missed some vital piece of information here that makes it plain that the true film negative exposure is in low single figures and not in the mid 20s

Thanks

pentaxuser

Hi Pentaxuser

Thanks for the thread and response.

I'll share with you my info based on what I've done so far and why I was asking.

I am currently experimenting , and have been working for a few years now, on ways of recording starlight on photo-paper - I know that there are great ways of doing this digitally, using film emulsions and with telescopes and dedicated sensors etc, etc.

But I'm interested in the actual light and its qualities - All quite introspective and weird, but it keeps me busy shall we say! I have even built two giant telescopes to do this (one stands a mammoth2.5 metres in height!)

What I do know is that with RA4 paper Fuji is faster in terms of exposure in comparison to Kodak RA4 products - In short its about twice as quick in terms of exposure time. Probably working around 10iso would be my best guess - I say guess, as some of the temperatures I work in (remember I have to have genuine dark skies to expose with) can be very cold on Dartmoor!

I can take exposures on RA4 over one night (averaging around 6-7 hours at around 5 degrees Celsius) and get some results on paper.

So the reason I was asking was to see if anyone had actually used or knew the 'film' ISO speeds of certain black and white papers. And (if like RA4 products) whether one paper or manufacturer was 'faster' than the other.

The reference to film ISO was so I could calculate rough exposure times to see if this was feasible to use ( based on my previous colour tests). I do know that black and white paper is generally slower than RA4.

I hope that helps clarify my request - Again I really appreciate all of you sharing your knowledge on this wonderful forum as the answers are always informed and thus help me strengthen my knowledge of this medium.

Andy M

ic-racer · Jul 10, 2020

jnantz said:
sadly these numbers the data sheets provide do not relate to ISOs relative to film ISOs.

Nothing sad.
ISO(P) speeds are driectly proportional ISO film speeds. If you read the datasheet it indicates the following:

ISO Speed (P)
NB ISO Paper speeds are not the same as Film ISO speeds, MULTIGRADE RC papers have approximately an equivalent Film ISO of 3-6.

Most sensitive paper currently available?

Andy M

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