# Pushing Tri-X 400 to 1600?



## burtharrris

There's a huge fundraiser at my school this weekend (www.thon.org) and I'm one of the organizing members.  I'm planning on taking my AE-1.  As much as I love it, I don't care about it cause it was $40 bucks on eBay.  Anyway, it's going to be in a gymnasium and standard academic/institutional hallways.  

It would make my life a ton easier to shoot with B&W to avoid color balance issues, and at ISO 1600 to avoid having to worry about a flash and low light.  If I push Tri-X 400 to 1600 using 35mm, will the grain and contrast become too obtrusive to make some nice 8x10 prints??  

Thanks everybody!


----------



## newrmdmike

yes, its been a while since i've done that but yeah you can . . . and it will be grainy, but i don't remember it bothering me too much


----------



## burtharrris

Oh yeah, I like some grain, I'm no so naive as to think it will be crystal clear.  Thanks Mike!

And, one sub-question (i'm looking in Torus34's direction... ): If I made a half-concentration developer and developed twice as long will it reduce contrast?  I remember reading something like that somewhere.


----------



## nealjpage

burtharrris said:


> If I made a half-concentration developer and developed twice as long will it reduce contrast?



Is that the same as 1:4 for something like D76?


----------



## fightheheathens

Im not really sure why you would want to push trix so far when you could use Either the Kodak or Ilford films that are rated at 3200 and pull them down to 16...
i mean either way you are gonna get grain and contrast, but you would probably get better results with a film that is designed to be shot at 1600.

I mean, unless you dont wanna pay for the film or have a truck load of TriX, then its a great idea


----------



## terri

I was told some years back by an instructor that it helped control grain by using 400 speed film and pushing it, than to use the higher speed film. I've not done any tests to qualify that statement, but I've pushed a lot of TMax and Trix X and developed it accordingly - you can still get very nice enlargements up to 8 x 10. They'll be somewhat grainy, but for me that's part of the charm. 

I can't answer your question regarding contrast control via half-concentrated developer - but I don't see that as being much of an issue in this case. You should be able to get enough control at the printing stage. Bracket your shots to give you a density spread to choose from your negatives, to be on the safe side.

Have fun!


----------



## Hertz van Rental

I used to regularly shoot Tri-X at 1600. It works quite nicely though you do get increased grain - especially in the mid-tones. And I never got good results at 3200.
D-76/ID-11 is the best developer.
The rule of thumb for push processing B&W is to increase dev time 15 - 20% per stop increase.
Take the dev time recommended for it's rated speed. of 400.
For 800 add 15 - 20%.
For 1600 add 15 - 20% of the 800 time.
ie:
ISO400 = 10min.
ISO800 = 10min + 20% = 12min
ISO1600 = 12min + 20% = 14.4min

Do some test shots and processing first to fine tune.


----------



## Don Simon

Hertz!? As the quote on your avatar says, we ain't seen you! Welcome back.

Would you come down on either side of the push slower / pull faster film question that Terri brought up? For some reason I'm more confident pulling than pushing so I've tended to use "3200" film and shoot it at 800 or 1600, only tried pushing 400 film to 1600 once and it didn't seem noticeably better or worse.


----------



## Hertz van Rental

Under normal conditions there is generally no advantage to be gained from pulling a B&W film more than a stop. There are times, though, when pulling a film a little can be beneficial.
First of all, for the benefit of people who may not know: 'pushing' a film means using it at an ISO higher than that at which it is rated.
'Pulling' means lowering the ISO from it's rated value.

To understand what is going on in both cases you need to remember the following:
When you increase (push) the ISO of a film you are, in effect, under-exposing it.
If it was processed normally the image would be very thin (if you got one at all). So to compensate you over-develop.
When you decrease (pull) the ISO you are over-exposing the film so to compensate you under-develop.

When you under-expose/over-develop a film you get low shadow contrast, high highlight contrast, a higher average density and a higher base fog level. Grain size also tends to be increased.
When over-exposing/under-developing you get low shadow contrast, low highlight contrast, low average density and low base fog. There is very little reduction in grain size.

Pushing a film therefore results in a higher contrast neg with increased grain but this is offset by the gain in film speed. It is useful for certain effects and situations and a reliable method of shooting in tricky conditions.

Pulling a film results in nothing more than a neg with lower than normal contrast. There are no advantages. And if you have enough light knocking around to be able to drop the ISO you would do far better to use a slower film. If that is not an option and you just have too much light for the film to handle then use a ND filter.


(...who was that masked man?)


----------



## Torus34

Burt;

Thank you very much for the mention, but in this instance, I yield the floor to Hertz!

And I would agree that fussing with push processing is enough to deal with without also trying to modify contrast.  You can do that with any VC paper during enlarging.

And welcome back, Hertz. I've missed seeing your posts.


----------



## Hertz van Rental

Torus34 said:


> in this instance, I yield the floor to Hertz!



You mustn't do that! The neighbours will complain.

And silly me I forgot the other point.

On the face of it, if a working strength developer takes 5 mins to develop a film then diluting it 1:2 means that it will now take 10 minutes...
Well, it would if Photography was logical and simple. But it isn't.
Diluting a developer reduces it's rate of development. This means that a diluted developer will never be able to produce the same emulsion contrast as it will undiluted.
This might seem to solve the problem of the increase in contrast from pushing the film, but like I said Photography isn't logical and simple.
Firstly, the rate of development (and the degree of dilution permissible) is dictated by the developer you are using.
Some, like Microdol-X, can stand being diluted quite a bit.
Others can largely stop working.
Again, the extra time you have to give when diluting will vary with how active the developer is. Some developers will take less time than you think, others more.
In short, you'll have to do some trial and error tests.

And then when pushing film you get higher than normal contrast in the highlights so diluting the developer will tend to reduce this. But you get lower than normal contrast in the shadows and... diluting the developer will reduce this too. The net result will probably be no real change except for slightly more loss of shadow detail.
And with some developers the reduction in contrast may not even be noticeable - you'll just get thinner negs.

Ah, Photography!
Dontcha just love it?


*Quick edit*
Using a more diluted developer, because it works at a slower rate, builds up the grain more slowly so you can sometimes get a bit of a reduction in physical grain size and therefore overall grain.
This is what happens when you use D-76 at 1:1 instead of as stock.
And why I used to like using Microdol-X at 1:3.


----------



## Don Simon

Regarding there being no advantages to pulling, another question... I was under the impression that Ilford and Kodak's 3200 film was actually rated at around 1000. In which case by shooting it at 3200 or even 1600 am I not therefore pushing rather than pulling it?


----------



## Torus34

Why am I suddenly thinking about Dr. Dolittle?

[Sorry.  Just couldn't hold that thought back.  Kinda like stifling a sneeze, you know?]


----------



## Hertz van Rental

Kodak's T-max 3200 is a bit of a strange one.
They make a lot of claims for it but nowhere in Kodak's tech literature can I find any explanation as to how it works.
According to Kodak it can be rated at anything from ISO800 to ISO25,000 depending upon developer with 'good results' at all of these speeds and 'finer grain than you would expect'.
If these claims were true then all other medium to high speed films should be obsolete - but they are not. Which leads one to think that the claims might be exagerated.
From the little I know about chemistry, physics and film sensitometry photographic emulsions have fixed speed ratings. Pushing and pulling does not alter this. So on the face of it the rating should be ISO3200 and dropping to 1600 or 800 is technically pulling.

On a personal note I find all T-max film to be pants - and quite fussy about choice of developer and use of fixer. I don't use the stuff and have always preferred Plus-X and Tri-X, which are beautifully behaved and have a much nicer quality to them.
Though I am sure others will choose to disagree.

(Dr Doolittle? Are you suggesting that you are talking to animals? Or is it a case of pearls before swine?  )


----------



## Don Simon

It was a fairly silly question really, only I had previously heard that Ilford 3200 was rated around 1000. I don't know why I mentioned Kodak as I don't shoot it. Anyway everything you said made perfect sense but it seemed like the high-speed films might be a bit of an exception. For example with HP5+ I take it for granted that it's rated at 400, then I expose for say 250, but I feel like I know where I stand. With the 3200 I'm less certain.

Of course I know I should really be testing it myself to work out what I'm happy with instead of asking, but I no longer have a darkroom and am scanning instead which isn't the best way to compare negatives. All I can really tell is that when I've exposed for 800, 1600 or 3200 with that film the negatives look good and the images are useable. Which I guess is all that matters.


----------



## Torus34

Hertz:

Wow! You picked the wrong reference! I wasn't trying to 'flame'.

'Push me-pull you!'

That's what bubbled up out of my mind.

Apologies for any misunderstanding!


----------



## burtharrris

Alright, sounds good, I'm going to have to expose a few test rolls before I try this.  This was a pretty important event for me so I might cry if I screwed them up! 

Thanks for everyone's help and insight.


----------



## Hertz van Rental

Torus34 said:


> Hertz:
> 
> Wow! You picked the wrong reference! I wasn't trying to 'flame'.
> 
> 'Push me-pull you!'
> 
> That's what bubbled up out of my mind.
> 
> Apologies for any misunderstanding!



I demand satisfaction, Sir! My seconds will call on you sometime in the next 50 years :smileys: 



*Note to any passing Mod: He just didn't understand my sense of humour. It's all sorted.


----------

