Does quantity affects developing time ?

[kex]

hi,
i have which is cheaper to ask than try.
If the concentration of the developer is the same,Does the quantity of the developer affects developing?
Can i use just enuff developer to get the negs fully submerged in it ?

Thanks~!

[dreamseeker]

Hi,

I think the quantity does not affect the timing. But was told by my instructor to fill up the tank to the top else there will be lots of bubbles when you agitate. (Also depends how you agitate I suppose?)

Maybe some other gurus can help you out on this one.

[sequitur]

Originally Posted by kex hi, i have which is cheaper to ask than try. If the concentration of the developer is the same,Does the quantity of the developer affects developing? Can i use just enuff developer to get the negs fully submerged in it ? Thanks~!

i believe you mean no. of millilitres of developer to use.

let's put it in chemistry terms.

no. of moles = concentration x volume.

you have a certain amount of.. uh.. what's the chemical on film.. let's say silver ions waiting to react with your developer.

so there're n moles of silver ions that require n moles of developer to react. if you put in a concentration of say 1/10 then you need a volume of 10n to get n. (n = conc x vol = 1/10 x 10n = n)

so if you vary the volume.. you're gonna get different amounts of n.. and well. it's not gonna match the film... so i think yes it does affect.. the volume of developer you put in.

[StreetShooter]

It probably only becomes a factor if your development time is long, and the developer gets exhausted.

For short development times at higher concentrations, you stop development long before the developer gets exhausted, so there should be no difference between developing 10 frames or 36 frames.

[kex]

i put an example,
if i'm using 600ml of developer at X time and get the result i want,will i get the same result if i reduce the amount to 300ml with everything else remaining the same ?

[sfhuang]

Originally Posted by kex i put an example, if i'm using 600ml of developer at X time and get the result i want,will i get the same result if i reduce the amount to 300ml with everything else remaining the same ?

yes you will.

[sequitur]

Originally Posted by sfhuang yes you will.

seriously i still stand by my n = conc x volume.

and i think you will not.

could run a test though.


no not me.

[tucker]

supposing if the dilution ration is the same,
suppse it will be the same as long the the negatives received equal submersion?

let's say I soak my towel in a pail of detergent of 1:2 ratio soap:water
what diff is there btw half pail and a full pail of detergent ?
well if my towel is V dirty then the half pail might just turn out uglier then the full pail?
suppose that happens then would'nt sequitur's theory be correct?


please, do run a test and let us know.
(I have no access to darkrooms anymore)
but I'll admit there's not absolute formulae where Darkroom techniques can be.

[hongsien]

Originally Posted by sequitur seriously i still stand by my n = conc x volume. and i think you will not. could run a test though. no not me.

Usually there is an overload of developer when you fully submerge the film. So, there is more than enough developer to react with your film, don`t worry about aving not enough developer to react with your film silver ions. In fact, there is a way to safe on developer: use the Jobo tank, it rotates on its side and you will need about 1/3 of the developer volume (concentration still the same of course). This contrary to the `normal` type of dip and dunk tanks which require alot of developer. Really, there is no need to have that amount of developer, it is only to fill up the tank! And, to let you buy more developer.....to make money for Kodak and the likes :-)

Hong Sien

[hongsien]

BTW: the reason for rotating or dip and dunk the tank is to replenish the debeloper that reacts with your film silver ions, the more you do this the higher the contrast.

Hong Sien

[ratboy]

use rodinal diluted 1:100
real cheap
keeps forever : )

Lam

[Mich]

Originally Posted by sequitur i believe you mean no. of millilitres of developer to use. let's put it in chemistry terms. no. of moles = concentration x volume. you have a certain amount of.. uh.. what's the chemical on film.. let's say silver ions waiting to react with your developer. so there're n moles of silver ions that require n moles of developer to react. if you put in a concentration of say 1/10 then you need a volume of 10n to get n. (n = conc x vol = 1/10 x 10n = n) so if you vary the volume.. you're gonna get different amounts of n.. and well. it's not gonna match the film... so i think yes it does affect.. the volume of developer you put in.

Originally Posted by sequitur seriously i still stand by my n = conc x volume. and i think you will not. could run a test though. no not me.

Serious sequitur, if u're so good in chemistry, why didn't it occur to u that that what streetshooter and sfhuang says make sense? I'm sure you will have MUCH more than your required n moles in the developer and the development time of approx 10 min will not exhaust the numerous moles of developer by the reaction that takes place.

nothing quite wrong with your equation but better to put more thought into the real chemistry before u make such ..... ..... remarks.

[Mich]

Originally Posted by kex hi, i have which is cheaper to ask than try. If the concentration of the developer is the same,Does the quantity of the developer affects developing? Can i use just enuff developer to get the negs fully submerged in it ? Thanks~!

i'm not sure if this helps but kex,

if u are developing one roll of film, using the normal jobo, paterson or ap tanks, u are all right using ~300ml of developer. U don't necessary have to use 600ml to top up the tank. using more won't change your development except to waste chemicals (as there is a lot more excess with 600ml)

Unless u want to ask the opposite. usually with 1 roll of film u use 300ml. if u wanna reduce the amount of developer (to less than 300ml), then u gotta be careful. that's when u MIGHT run into exhausting the developer (as there is less to begin with) AND more importantly, u won't be immersing all your film with the solution thus might get uneven development.

Hope i've sort of cleared your doubts.

Trying to explain with SIMPLE logic not some bombastic (i think simple) scientific equation. I could have a phD in chemistry but no need to flaunt it. (although i'm not implying people who throw up equations have a BSc in the first place)

[kex]

thanks for all input,
i'm using the CD rom spindle cover to develop 120 film reeled into the loader and trying ways to reduce the amount of chemical used(ard 800ml)
lost the black developing container and trying to stinge abit here and there.

[sequitur]

Originally Posted by Mich Serious sequitur, if u're so good in chemistry, why didn't it occur to u that that what streetshooter and sfhuang says make sense? I'm sure you will have MUCH more than your required n moles in the developer and the development time of approx 10 min will not exhaust the numerous moles of developer by the reaction that takes place. nothing quite wrong with your equation but better to put more thought into the real chemistry before u make such ..... ..... remarks.

serious Mich, i'm trying to explain it and i didn't mean anything offensive. and i think you ought to put some thought into the (human) chemistry as well before you make such.............................................. ........ remarks.

i didn't say what they say don't make sense. i'm just saying what i think. so if i'm wrong then i'm fine with it also.

[tucker]

hi kex,
ya're shooting medium format ?
cool.

erm, what happened to ya tank !?

[kex]

Originally Posted by tucker hi kex, ya're shooting medium format ? cool. erm, what happened to ya tank !?

Long story la,
i used to develop 120 with about 100ml only using my dad's own developer formula for 2mins 30 sec with the *pulley technique* where u submerge the film in developer and start doing the pulley with both hands each holding one end of the Film.
recently try to play Darkroom again but dun have the raw material for mixing chemical anymore,so have to rely on ready mix type.
i stumbled upon a new old auto loader(maybe ard my age) in my storeroom by chance last week but there is no container.
so i tot of using the spindle cover as substitute as i have a darkroom which is dormant for 11yrs liao hahaha..

[tucker]

interesting technique!

I'm still figuring out my direction in Black and white.
let me get hold of a regular darkroom and maybe we can exchange techniques.

have fun.

[kex]

Originally Posted by tucker interesting technique! I'm still figuring out my direction in Black and white. let me get hold of a regular darkroom and maybe we can exchange techniques. have fun.

i'm having so much fun in darkroom these few nites,hehehe..
experimenting with diff exposure and training my judgement on prints in the dim safe light.
printed some on a batch of 11yrs old B&W paper and it still turns out well!!
still got about 20 boxes of old paper in my darkroom
to think i threw away 30+ boxes of B&W paper a few yrs back thinking they should be spolit while clearing my house.
Now my fav film is Ilford,they print quite nice and react well with Bromophen.
Kodak 400CN is quite hard to get it right,need to experiment more on it..but it has really fine grain.
the main reason i going back to Darkroom printing is becoz i feel dat it is cheaper to learn 4x5 format.Sheet film cost about $60 for 50 sheets of Tmax while slides cost $25~! for pack of 10 sheets with developing cost of $4+ each which means every click is almost $7~!
B&W cost only a small % of it and i gain full control of the whole process

[kex]

ok i did my developing using only 200ml and turns out very good.
at 1st wanted to use the auto loader method + ilfosol 1:9 (20deg)800ml @ 6mins.
But spend 20mins trying to load that ~!@#$%^& into the loader
so end up using my old method of *pulley* developing.
i poured 200ml of the same dilution into a 5x7 tray and started pulling for 6mins,go thru running tap and fixed it using Hypam Fixer 1:3 for ard 3mins then soak in water.
Was very surprised and happy with the developed Negatives~!

Contact Printing was a breeze compared to 400CN