Downrating HP5+

I just experimented recently with downrating HP5+ to 320; then I went back to

exposing normally at 400. Let's just say I will be shooting at EI 320 from now on.

 

I have a question about downrating though. What I did was I metered for EI 320

(set the ISO speed to 320) and developed normally according to times listed for

400. When you downrate, suppose to 200, do you then change the development time

or still use the time listed for 400? And if you can do both, what is the

difference between the two?

 

One more thing; as I don't have access to a darkroom currently but intend to in

the future, would you need to expose/develop prints at different times if you

downrate HP5+?

when i was still shooting hp5, i normally exposed it at 250. developed minus 15% (if i remember correctly, or maybe it was 10%?) from what the xtol datasheet gave me (at 1+1). that was for overcast days/diffused light. on sunny days i exposed it at 64, and developed n-2 (a little over half of my initial time). i guess i could say that i treated it as an iso 250 film, held back on developing to save the highlights from blowing, and if the light conditions were harsh, i pulled even more to get some life to the shadows. then i needed to pull developing even more, to keep the highlights in place. i shot it mostly on 35mm, so i was never a candidate for the zone system, but i guess we could call this approach "the quick and dirty zone".. i recommend the adams book, the negative.

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regarding <i>"When you downrate, suppose to 200, do you then change the development time or still use the time listed for 400?"</i>, my general suggestion would be that if you pull exposure, you'd have to pull developing too. otherwise you'd get blown highlights. but then, i don't know what effect you're after...

The difference between 400 and 320 is so little that normal development would not give you a very dense neg. If you are doing it because you think the normal exposure is wrong, then this is your "normal exposure" .If you are doing it to reduce contrast , I would rate it at 200 and under-develop it.

I apologize, I should have specified why I want to shoot at EI 320 from now on. My biggest reason is to reduce grain. The latest photos I developed from D76 (shot at EI 400) had significantly more grain than the previous batch (which were shot at EI 320). I will post a few examples later today (from the EI 400 batch).

 

While on the subject of reducing grain, what dilution of D76 would yield the least amount of grain? I'm currently using 1:1, and developing according to whatever temperature the tap + stock come to (between 70 and 80 degrees).

doh,.. and i instantly assumed it was a contrast thing..- wellwell ,-)

D76 at 1 to 1 , gives you larger grain than D76 straight.Large grain is caused more by development than exposure.If you have a lot of grain ,then less development in D76 straight is the way to go. I would think your photos would be pretty flat contrast wise if you are pulling the film and developing in D76 1 to 1. I only do that with Arizona daylight in the summertime , midday.

By the way I find less grain at 68 degrees,rather than developing at higher temps. This causes the medium the grain is suspended in, to swell.

Well, the contrast wasn't an issue with the previous batch of photos I took (the scenes were extremely contrasty though) when I pulled to EI 320. In fact, the only difference I did notice was that the grain was much less visible and the images were also much sharper. Smaller grain + sharper images.

Grain is more a function of the film than the development. If you have enough light to shoot at ISO 100 or 80, try FP4 of Plus-X. You'll find they have a significantly finer grain than HP5, but more contrast (which is why I'd rate them at 80 of 100).

Yes, when you downrate film you reduce development time. Typically, I rate HP5 at 160 ASA and reduce development time by about 45 percent from the 400 ASA time. Downrating reduces the contrast of the negative and thus allows the film to capture a wider subject brightness range. In dull light I might use the film at rated speed or downrate only by 1/3 or 2/3 stop, reducing development time by 10 or 20 percent respectively.

I shoot HP5+ EI 200 and develop in D-76 1:2 for 12 min @ 68 deg for normal development. And when I want less grain, I shoot larger film.

Get a copy of Ansel Adams' book "The Negative", plan on spending lots of time (and money) finding out what works for you, and remember that if you shoot a variety of subjects under various lighting conditions, maybe even using different lenses, all on the same roll, you're just chasing your tail.

 

You'll also need to get your shutters tested at every speed. 320 to 400 is less of a difference than your shutter speeds can be "off" while still being within accepted tolerances. Have fun!

David, if you are shooting 35mm may i suggest that you check out first the book "the zone

system for 35mm photographers" by Carson Graves ?

for a long time i was exposing hp-5+ at about 200iso and the pulling development

between 25 or 30% and getting very low contrast negatives,requiring printing at grade 4 or

4.5.basically what Michael is saying. now i am exposing at normal speed and pulling

development just a little,like 10% to keep the highlights from blowing up. hope this helps.

i think smaller grain gives you less sharp images.

Also check your thermometer! Years ago we'd use a Weston dial thermometer because it was fast and easy to read, but from time to time check that against our Kodak Process Thermometer (big, slow, and big bucks too) to find out just how far off the dial thermometer was. Now there are a bunch of Weston look-alikes out there. A few months ago I was at the photo supply and checked a bunch of dial thermometers against one another. There was about a 4 degree f spread between the hottest and the coldest, and the two Westons I checked were a hair more than a degree off from one another. If you're using a mechanical timer that might not be spot-on either.

If you see a very obvious difference between the two films, the difference is probably caused by something other than the 1/3 stop of difference in exposure.

 

The manufacturers' recommendations (or any recommendation, as a matter of fact) are a reference for starting somewhere, from which you can get your own development time by adjusting it according to the results that you get. It's unlikely that the original recommendations will be spot on for your taste. If the recommended development time for EI 400 works good at EI 320, well then, that's your time for EI 320, and not 400.

 

As a general "rule", exposure controls shadows, development controls the contrast. So all other things being equal, increasing exposure will increase the density of both shadows and highlights, and reducing exposure reduces the density, again, of all brightness levels. On the other hand, all other things being equal, increasing development will only increase the density of the highlights, while shadows stay where they are. Similarly, reducing development will bring the density of the highlights down, so the whole image will have less contrast. In theory, changing development does have a very little effect on the shadows, but in practice, this is most of the times negligible.

Defiantly calibrate your thermometer as a 10% change in development can be made with a few degrees temperature change as well as a change in time. Exposure between EI 400 and 320 isn't very large compared to a loss of temperature control in development.

 

Have you considered trying a change in developer to reduce grain? Perhaps Microdol-X? D-76 is a general purpose developer not known as a very fine grain developer.

 

Formulary Wimberley WD2D+ Pyro is a staining developer capable of less grain and is supposed to work well with HP5 but tricky from what I've read. Never used that yet. (I'd try the Microdol first.)

"Expose for the shadows, develop for the highlights"

ie Exposure determines shadow detail on the negative and development time determines the brightness of the highlights. If theres a lack of detail in the shadows your personal EI-exposure index is to high and needs to be decreased to give more exposure eg shoot at 320 or lower to give a 1/3 stop exposure increase.

If your highlights are blown the development time was to long. But the development time is determined by the contrast of the scene being photographed ie flat or contrasty. The trick is to fit the contrast of the scene onto the film. Personal film tests is the way to go here and its not difficult it just needs a little time and a little determination - once the dark rooms up and running!

 

"When you downrate, suppose to 200, do you then change the development time or still use the time listed for 400? And if you can do both, what is the difference between the two?"

 

Shooting 400 ISO @ 200 ISO is exactly the same as giving 1 full extra

stop of exposure to the negative.

And shooting at different ISO's affects the development time.

Shooting at a lower ISO would 'generally' mean shortening the development time to compensate for the increased exposure in the highlights.

As has been said Read Ansels book The Negative.

For me a better place to start the journey before moving on to Ansel was "The Practical Zone System" By Chris Johnson. Very well written.

It really moves photograph out of the shadows and into the light.

 

Hope this help a bit?

Best regards

Kev

What size is your enlargement? You should not see a difference in grain from 400 to 320. Check everything as others are posting. Ensure the developer remains at a constant temp by using a water bath (if required), use the same agitation pattern, enlarge on the same type paper, etc. Are you evaluating grain based on a comparison of similar tonal areas such as empty skies? Are the two prints of similar contrast as high print contrast reveals more grain.