HP5 Overexpose / Underdevelop Question

[DH_Studio]

Hi all.

I shot a roll of HP5 (120) and rated it @ 200 ISO instead of 400.

I'm processing in D76 (1+1) and I pulled the data sheet but there are no times for processing HP5 rated at anything less than the El rating of 400 in D76.

Rated at 400 the time is 11 minutes, at 800 it goes up to 13 minutes. Trying to figure out how long to develop if rated at 200. Does anybody have that info?

Thanks!

 

[Lachlan Young]

About 9-10 min, 1+1, 20oC is often a good place for EI 200 HP5+ in ID-11/ D-76.

 

[Andrew O'Neill]

My time is 9:00. 20°C. Same as Xtol 1+1.

 

[Juan Valdenebro]

Hi all.

I shot a roll of HP5 (120) and rated it @ 200 ISO instead of 400.

I'm processing in D76 (1+1) and I pulled the data sheet but there are no times for processing HP5 rated at anything less than the El rating of 400 in D76.

Rated at 400 the time is 11 minutes, at 800 it goes up to 13 minutes. Trying to figure out how long to develop if rated at 200. Does anybody have that info?

Thanks!

Hello DH,
Ilford's official times don't include times for HP5+ at 200 because for normal contrast scenes that film reaches 400 in normal (MQ) developers... 200 is OK for direct sunlight scenes, though, with shorter development times...
If you used 200 under soft overcast light, anyway your negatives will be totally fine...
By the way, I use that film for overcast at 640 precisely in D-76 1+1, at 22C... That's for a Kaiser condenser enlarger, with the Nikon 50mm f/2.8, with Dektol and Ilford warmtone multigrade paper.
My times are 10% less than Ilford times.
In your case I would develop normally, as if 400 was the EI used... I see 13 minutes at 400 with Ilford agitation: 4 inversions in the beginning and 4 inversions every minute, for D-76/ID-11 1+1 at 20C...
11.5 minutes at 20C for condenser enlargers, or 14.5 minutes at 20C for diffusion enlargers should give you negatives precise enough for wet printing, using Ilford agitation...
With Kodak agitation (I do 8 fast inversions in the beginning and 4 fast inversions every 30 seconds 'cause I use D-76) times become shorter...
D-76 and ID-11 are basically the same developer: just take into account if you'll use Ilford or Kodak agitation. Current D-76 works very well with fast inversions, as recommended by Kodak.
So, depending on your enlarger, your enlarging lens, the scene contrast, and depending also on the type of agitation used, only you can find what's optimal for your equipment, in the range of 8 to 12 minutes, now you exposed at EI200.
As you see, not an easy fast answer.

 

[Sirius Glass]

In your case I would use the development time for ISO 400 and get a slightly denser negative than normal which will yield more shadow detail since you are letting in 1 f/stop extra.

 

[zanxion72]

+1 for using normal development as if it was ISO400. HP5 gives anyway thin negatives with standard development times and it does not build much of dense due to not being any silver rich bw film anyway. You may get a bit more density than expected, but it will be quite manageable. You can also compensate the overexposure with by using minimal agitation, say every other minute.

 

[Lachlan Young]

HP5 gives anyway thin negatives with standard development times

Only if you give vastly insufficient agitation and maintain the wrong temperature and/ or don't follow Ilford's times.

and it does not build much of dense due to not being any silver rich bw film anyway.

No. If the silver cannot be used & sensitised then it's literally being wasted. Silver content is the most irrelevant and useless comparator there is. Some developers act to restrict maximum density in order to make negatives 'easier' to print.

 

[zanxion72]

Only if you give vastly insufficient agitation and maintain the wrong temperature and/ or don't follow Ilford's times.

No. If the silver cannot be used & sensitised then it's literally being wasted. Silver content is the most irrelevant and useless comparator there is. Some developers act to restrict maximum density in order to make negatives 'easier' to print.

Ilford's suggested times and standard development agitation for all of its films gives you thinner than expected negatives with Pan F+ being the only exception. Take Delta 3600 for example. If you use the times that Ilford suggests you will get quite thin negatives. HP5 suggested times give so thin negatives, that one stop overexposure will bring it to just about right. Also, in D-76 the true speed of HP5 is something like 250-320.

Silver rich films give you negatives with higher Dmax and the buildup due to overdevelopment is faster than other films. It is always a function of how much silver gets affected by the same amount of light and the proof of it is that different films give different results in the same development time. With your logic, all films should require the same development time in the same developer which certainly isn't true. Also, the development time is the variable that defines the maximum density and not the developer (unless you use a solution so weak that the developer gets exhausted before the film gets fully developed).

 

[Lachlan Young]

Ilford's suggested times and standard development agitation for all of its films gives you thinner than expected negatives with Pan F+ being the only exception.

Silver rich films give you negatives with higher Dmax and the buildup due to overdevelopment is faster than other films. It is always a function of how much silver gets affected by the same amount of light and the proof of it is that different films give different results in the same development time. With your logic, all films should require the same development time in the same developer which certainly isn't true.

Firstly, it sounds like your development technique is off, Ilford's times are usually very close to correct.

Secondly, silver content has nothing to do with it. What matters is how well that silver can be sensitised and used - today's films are faster for a given granularity because they can use more/ almost all the silver they contain. The only films that require heightened silver content are those intended for reversal development. All other claims about 'silver rich' films are marketing hype, not photochemical reality. Some developers are able to access/ release more iodide from the emulsion (specifically the slow emulsion component) restraining maximum density. Others don't, making potentially denser highlights.

 

[zanxion72]

Firstly, it sounds like your development technique is off, Ilford's times are usually very close to correct.

Secondly, silver content has nothing to do with it. What matters is how well that silver can be sensitised and used - today's films are faster for a given granularity because they can use more/ almost all the silver they contain. The only films that require heightened silver content are those intended for reversal development. All other claims about 'silver rich' films are marketing hype, not photochemical reality. Some developers are able to access/ release more iodide from the emulsion (specifically the slow emulsion component) restraining maximum density. Others don't, making potentially denser highlights.

Firstly, my development style is not off but exact and very consistent.
Second, you should know by experience what is the true speed of the HP5 in D76.
Third, it is commonly admitted that the development times that ilford suggests, give thin negatives.
Fourth, the developer does not access/release anything! It gets absorbed by the emulsion and reacts with the silver ions converting them into silver metal. The unexposed silver-halide (Silver Bromide, Silver Iodide or Silver Chloride) crystals are removed in what is called the fixing bath. The density is a factor of development time. You can reach maximum density in any developer. Don't mix it with the term plain "density" where anything with density higher than 5 is virtually opaque. Dmax is the maximum density a film can achieve and this can be done in any developer.

 

[138S]

Rated at 400 the time is 11 minutes, at 800 it goes up to 13 minutes. Trying to figure out how long to develop if rated at 200. Does anybody have that info?

Also, if your scenes didn't have very, very strong highlights you may simply use the same development time than for 400 speed, don't worry much. Also nothing wrong if shortening development a bit for EI 200, personally I would not shorten it much, or I would shorten it a fraction of what stated in the table.

Many people rate negative film at lower EI than the ISO stamped on box without a correction in the development. Also it depends on how you meter. YMMV...

In fact, box ISO speed was doubled in 1960 with no change in the film manufacturing or in the development times, you simply have exposed like it was standard before 1960. Post 1960 shots were not better exposed than Pre 1960, but Post 1960 speed pushing allowed faster shutter speed (or more DOF from aperture) yielding sharper shots in general.

Slides are different because overexposing easily harms, but overexposing a bit (one stop is a bit) negative film usually does not harm and it even may be benefical.

With color negative film, you have to overexpose many stops to start damaging the image:



http://canadianfilmlab.com/2014/04/24/film-stock-and-exposure-comparisons-kodak-portra-and-fuji/

 

[radiant]

With color negative film, you have to overexpose many stops to start damaging the image:

.. and do you still think we need to spot meter

Continuing joking around: this is why Sunny 16 rule works. You really don't need to have any clue of the lightning conditions

Edit: Example of under/over-exposure on HP5 https://carmencitafilmlab.com/wp-content/uploads/HP5-Bracketing.jpg

 

[138S]

Second, you should know by experience what is the true speed of the HP5 in D76.

D-76 is a full speed developer, and ilford usually stamps on box a "full ISO speed".

Let me mention what I mean with "full ISO speed": ISO norms in force today allow to use any developer for the box ISO speed calibration, but main manufacturers (Kadak/Fuji/ilford) try to stamp a calibration consistent with a Full Speed Developer. Some manufacturers like Foma use for the calibration an Speed Increasing Developer and a higher contrast than the one stated by the ISO norm, still all is well mentioned in the Foma datasheet. Also calibrated Speed is rounded to use an standard Box speed.

Personally I don't find that development times stated by ilford do deliver thin negatives, but all depends on several factors like agitation or developer freshness.

___________________

If wanting to nail standard development before refined adjustments, on has to obtain around 0.62D (additional over base+fog density) in an spot metered +/-0

One may purchase an Stouffer T2115 density wedge to compare, it can be scanned alongside the negative, so density can be determined without having a densitometer.

 

[138S]

.. and do you still think we need to spot meter

Continuing joking around: this is why Sunny 16 rule works. You really don't need to have any clue of the lightning conditions

Edit: Example of under/over-exposure on HP5 https://carmencitafilmlab.com/wp-content/uploads/HP5-Bracketing.jpg

For sure, but sometimes we require a refined spot metering, this was my second 8x10 shot ever: https://www.flickr.com/photos/125592977@N05/24852468435/

In that shot I had 8 to 10 stops dynamic range in LIRF conditions selectively in the shadow areas, depending on what considered, I'm pretty sure that only a refined metering allowed me to nail the shot like I wanted it, with no bracketing but shooting two sheets to have a backup.

With slides... if we have a bright sky then also spot metering can be quite useful, it tells what graded ND we need to conserve highlight texture, while preserving shadows.

Edit: Example of under/over-exposure on HP5 https://carmencitafilmlab.com/wp-content/uploads/HP5-Bracketing.jpg

That test is totally flawed: At -5 you always have a black image. ISO calibration is based in the film speed point, by -3.33 underexposure you have 0.1D over base+fog, try it... So at -4 you have nothing, quite a weird metering had to be there.

 

[Lachlan Young]

Firstly, my development style is not off but exact and very consistent.

Maybe so, but it sounds like you are still not getting that you can be 'exact' but wrong - consistently.

Second, you should know by experience what is the true speed of the HP5 in D76.

Ilford's box speed is based on ISO standards in the standard developer they use for ISO tests - aka ID-11.

Third, it is commonly admitted that the development times that ilford suggests, give thin negatives.

Only if you use a soft light source and want contrastier negs. G-bar 0.62 is the standard, but some may prefer softer for condensers and harder for diffusion. The EI 800 times for HP5+ are essentially a G-bar 0.7 which Ilford used to recommend for cold cathode heads. The spread of grades on many variable contrast heads is not consistent either, so you can draw severely error ridden conclusions by relying on them.

Fourth, the developer does not access/release anything! It gets absorbed by the emulsion and reacts with the silver ions converting them into silver metal. The unexposed silver-halide (Silver Bromide, Silver Iodide or Silver Chloride) crystals are removed in what is called the fixing bath. The density is a factor of development time. You can reach maximum density in any developer. Don't mix it with the term plain "density" where anything with density higher than 5 is virtually opaque. Dmax is the maximum density a film can achieve and this can be done in any developer.

The relationship of solvent developers and iodide placement in emulsions has evolved dramatically since the 1950s. And much more radically than many badly sourced pseudo-technical texts seem to admit or understand. As the more solvent developers act, they release iodide (amongst the other byproducts) from the emulsion - this iodide has a micro-restraining effect, enhancing sharpness/ edge effects/ microcontrast. But if you place more iodide (in the slow emulsion set) where it can be more rapidly accessed by the more solvent developers it can have a stronger and stronger restraining effect, stopping maximum densities running away. Lower solvency developers (Rodinal) don't do this/ do this as strongly - and indeed, many so-called 'compensating' developers/ developing 'techniques' do nothing of the sort, they simply develop to an effective (but low) gamma infinity, running out of developing ability long before they develop much density in the highlights.

 

[zanxion72]

Maybe so, but it sounds like you are still not getting that you can be 'exact' but wrong - consistently.

That's what you think, but it is not as you think.

Ilford's box speed is based on ISO standards in the standard developer they use for ISO tests - aka ID-11.

Only if you use a soft light source and want contrastier negs. G-bar 0.62 is the standard, but some may prefer softer for condensers and harder for diffusion. The EI 800 times for HP5+ are essentially a G-bar 0.7 which Ilford used to recommend for cold cathode heads. The spread of grades on many variable contrast heads is not consistent either, so you can draw severely error ridden conclusions by relying on them.

The true speed of HP5 in ID-11/D76 is closer to 320 than 400. If you don't believe me, google it and see what you'll get.

The relationship of solvent developers and iodide placement in emulsions has evolved dramatically since the 1950s. And much more radically than many badly sourced pseudo-technical texts seem to admit or understand. As the more solvent developers act, they release iodide (amongst the other byproducts) from the emulsion - this iodide has a micro-restraining effect, enhancing sharpness/ edge effects/ microcontrast. But if you place more iodide (in the slow emulsion set) where it can be more rapidly accessed by the more solvent developers it can have a stronger and stronger restraining effect, stopping maximum densities running away. Lower solvency developers (Rodinal) don't do this/ do this as strongly - and indeed, many so-called 'compensating' developers/ developing 'techniques' do nothing of the sort, they simply develop to an effective (but low) gamma infinity, running out of developing ability long before they develop much density in the highlights.

What is mainly released from the emulsion is bromide and not iodide! That's what most films have, silver bromide (hence bromide drag). The amount of halide released from the emulsion is minimal, it so minimal it does not affect the development not to any measurable degree!

 

[koraks]

Silver rich films give you negatives with higher Dmax and the buildup due to overdevelopment is faster than other films. It is always a function of how much silver gets affected by the same amount of light and the proof of it is that different films give different results in the same development time. With your logic, all films should require the same development time in the same developer which certainly isn't true.

Two things:
1: the amount of silver per surface measure is not the only, or even most important, parameter that affects the rate of development. Factors such as hardening play a very significant role as well, as will other factors related to physical silver particle structure and emulsion permeability.
2: whether or not HP5+ is 'silver rich' is IMO not a very relevant issue. It's by far 'rich' enough in silver to easily reach a contrast that surpasses the ability of even the softest grade of paper to print well. In other words: plenty of silver in there for pretty much any purpose. Again, the absolute amount of silver isn't very interesting; look at e.g. TMAX100 which is allegedly extremely 'poor' in silver, but still gives excellent maximum density (in an absolute sense) due to the particle structure and alignment. Absolute silver load of an emulsion isn't really a relevant criterion these days - if only because not a single manufacturer actually publishes any useful specifications on it. Which makes sense, as it simply doesn't say much from a functional viewpoint, unless you're running a silver recovery operation.

 

[pentaxuser]

Having seen a number of reviews on HP5+ the usual criticism is that the negatives have too many greys in them and lack "punch. It might be interesting to see what happens to that "punch" if the OP does what has been suggested and exposes for 200 but develops for 400

Form my understanding there is little to lose by doing this and it might result in negatives with more punch that are easier to print in terms of getting more contrast, if that is your taste. Even if it doesn't do what you were hoping it might do they will still be OK negs from which OK prints are lilely to be no more difficult to obtain

It is only by such means that a user might know if this kind of a change is worthwhile for him

pentaxuser

 

[Lachlan Young]

That's what you think, but it is not as you think.


The true speed of HP5 in ID-11/D76 is closer to 320 than 400. If you don't believe me, google it and see what you'll get.

The EI you prefer to expose the film at may differ significantly from the ISO defined box speed. If I choose to expose HP5+ at an EI of 200, that does not mean that the ISO is not 400. You are currently confusing the two. Metering technique, if it departs from the standards that define film speed, will also give you an apparent error in effective exposure index.

What is mainly released from the emulsion is bromide and not iodide! That's what most films have, silver bromide (hence bromide drag). The amount of halide released from the emulsion is minimal, it so minimal it does not affect the development not to any measurable degree!

Wrong. You can learn the reality on here, but you need to drop your mis-informed assumptions. Of course film development releases bromide, but the exploitation of iodide behaviour and placement is absolutely critical to making modern fast BW and good colour emulsions that have good sharpness. Components in the PPM range can have drastic and measurable effects on the sensitometry of films.

 

[radiant]

That test is totally flawed: At -5 you always have a black image. ISO calibration is based in the film speed point, by -3.33 underexposure you have 0.1D over base+fog, try it... So at -4 you have nothing, quite a weird metering had to be there.

In your canadianfilmlab test there was -3 stop exposure as example and based on what you wrote that should be quite dark, I believe. But it is not.

I'm not saying the test is perfect, but carmencitafilmlab is a pretty known and reliable lab.

Here is HP5 "pushed" to 6400 (4 stops) https://emulsive.org/wp-content/upl...5-EI-6400-Ilford-DD-X-14-Mamiya-645-Super.jpg and https://emulsive.org/wp-content/upl...HP5-EI-6400-Microphen-Stock-Canon-EOS-650.jpg

Based on your claim 4 stops underexposure should be dark. But it isn't.

 

[Andrew O'Neill]

In your canadianfilmlab test there was -3 stop exposure as example and based on what you wrote that should be quite dark, I believe. But it is not.

I'm not saying the test is perfect, but carmencitafilmlab is a pretty known and reliable lab.

Here is HP5 "pushed" to 6400 (4 stops) https://emulsive.org/wp-content/upl...5-EI-6400-Ilford-DD-X-14-Mamiya-645-Super.jpg and https://emulsive.org/wp-content/upl...HP5-EI-6400-Microphen-Stock-Canon-EOS-650.jpg

Based on your claim 4 stops underexposure should be dark. But it isn't.

Your example is dark. That's exactly what I expect to see when HP5 is pushed to 6400. Empty shadows. Wouldn't it be great if someone came out with a real, high speed film? For now, 3200 will have to do.

 

[Andrew O'Neill]

Hi all.

I shot a roll of HP5 (120) and rated it @ 200 ISO instead of 400.

I'm processing in D76 (1+1) and I pulled the data sheet but there are no times for processing HP5 rated at anything less than the El rating of 400 in D76.

Rated at 400 the time is 11 minutes, at 800 it goes up to 13 minutes. Trying to figure out how long to develop if rated at 200. Does anybody have that info?

Thanks!

So, what did you end up doing?

 

[radiant]

Your example is dark. That's exactly what I expect to see when HP5 is pushed to 6400. Empty shadows. Wouldn't it be great if someone came out with a real, high speed film? For now, 3200 will have to do.

There isn't much in shadows at 3200 either https://emulsive.org/wp-content/upl...rd-HP5-EI-3200-Ilford-DD-X-14-Canon-EOS-1.jpg

Dunno what is maximum dynamic range one can achieve when exposing to 3200 or 6400 .. I bet printing those negs might be challenging

 

[138S]

1: the amount of silver per surface measure is not the only, or even most important, parameter that affects the rate of development.

IMO you are right, this is complex matter. Perhaps it depends on several factor factors... an energetic developer will promote more the infectious development, in that case probably a silver halide rich film will go faster. Also as development advances there are more chances that a grain infects the other ones, making a difference if a silver rich emulsion has more halide in the same gelatin volume... but also a film with less total silver may have less gelatin, thus promoting infectious contact of an exposed crystal with neighbour non exposed crystals... And sure many other factor are involved...

 

[Lachlan Young]

Even if they do, they are not in a position to carry out accurate tests, certainly not with 1/3 stop precision. Mostly what you will find are zone system EI testers.

What is quite interesting/ amusing when dealing with questionable zone-driven EI's is that when you dig under the zone sticker on the Pentax digital spot meter & look at the difference between 'zone II' and the IRE 10 shadow index (1 on the x10 scale the Pentax uses) the difference between them is almost exactly the 1/3 to 1/2 stop of EI that Zone system adherents claim to think films are slow by (depending on how badly made the sticker is).