n_dhananjay3

Its a nice film - not as much halation as HIE (HIE didn't have an

anti halation backing, while Maco does) but loads better IR effect

and Wood effect than the Ilford and Konica films - it is supposed to

have peak sensitivity around 820nm. I developed it in XTOL 1:3 for

about 12 minutes, EI was in the region of 10 or so with an IR filter

in bright daylight. Pretty clean and nice results. Cheers, DJ.

I believe its to accomodate your individual focussing distance. There

should be a reticle (a hairline or a circle on the mirror). Move the

focusser till your eye is able to comfortably bring the reticle into

sharp focus. This way, your eye is not straining to bring something

into focus. Its the same principle as a diopter correction. Cheers,

DJ.

I've toyed around with salted paper, which is a POP process. Printing

out processes do not require development of a latent image - the

paper blackens automatically on exposure to light (it still needs to

be fixed to make the image permanent though). Yes, POP paper

accomodates a much longer density range. The basic reason for this is

that the paper is self masking. If you use a contact printing frame,

you can see the process at work by opening the back. In the shadows,

density will appear readily but the deposited silver tends to slow

down the emulsion in these areas by masking the light - this is what

is meant by the self masking process. So the shadows take a long time

to develop to a good black, which gives enough exposure to the

highlights. As a result of this self masking, the paper accomodates a

very long density range. Depending upon whether you are going to buy

POP versus coating a paper yourself, you might have some room for

play. For example, if you're coating your own paper, dichromate can

be used to increase contrast a bit.

<p>

Now obviously, you getting the required negative needs expansion

i.e., overdevelopment. The problem with overdevelopment is that it

tends to increase grain. Now personally, I think this whole bit is a

little over reacted to because this is a contact printing process -

the grain would be more likely problematic with an enlarging process.

But the consensus seems to be that overdevelopment does not work as

well as it used to. In any case, that is the reason for the

popularity of staining developers like pyro and pyrocatechin with

such processes. Pyro is a staining developer. So part of the density

comes from the stain. Since that is the case, the silver image itself

needs to be developed to a lower contrast index, which thereby allows

you to avoid the graininess that comes with overdeveloping the silver

image. Of course, pyro has a bunch of other advantages also including

the fact that it is a sharp developer (creates adjacency effects),

makes developing by inspection easy etc. You could buy the necessary

powders and mix up the developer if you want. The powders should be

easy to take with you. Keep in mind that pyro is quite toxic and use

appropriate caution in using it. Having said that, I see no problem

with utilizing materials you are familiar with for the

overdevelopment. Another option is to buy film and developers you are

comfortable with and develop them the normal way. Then make a

duplicate negative which is overdeveloped. A couple of advantages to

this. One, you can have negatives for each process. Two, you get a

little more points of control to tweak the neg for the POP process.

You could buy some Kodak SO-132 direct duping film or buy some lith

film for making the second negative. Lith film will develop to a

fairly high density range quite easily.

<p>

Good luck, DJ

Interesting. I think that does make for a handier design on two

counts. One, thats already been mentioned, is that the glass protects

the shutter. Two, when the cell is used behind the stop, the

principle point of the cell lies behind the lensboard, which means

that the bellows extension is definitely longer than the marked focal

length, an unwieldy proposition, especially with cameras having

limited bellows extension. When the cell is used in front, it does

act as a tele since the principle plane is out in front of the lens.

I wonder how the design adjusted for the stop position, though it was

probably do-able. But I'm fairly sure the Symmars and the Protars

suggest using the cell behind the stop. In any case, with a little

stopping down and use of a strong, monochromatic filter, results can

be quite decent. Not quite upto a modern, prime lens but pretty damn

decent. Cheers, DJ.

I believe, unlike the convertible Protars which were symmetrical

designs, the convertible Symmars are not truly symmetrical. The

symmetry would typically automatically correct some of the

aberrations, fully at 1:1 and a good deal even at other distances.

When a single cell is used alone, one loses the symmetry and thus

some of the corrections, which is why the performance is not as good

as the combined unit - stopping down helps reduce some of these

aberrations. The single cell should always be used behind the stop,

because the position of the stop helps to correct some aberrations.

However, sometimes, when the cell is used behind the stop, it

increases bellows draw considerably and so the cell is sometimes used

in front of the stop to reduce bellows draw. The performance will be

worse in this position but in some situations the shorter bellows

draw may be more important. Stopping down does not help lateral

chromatic aberration and so, when using a single cell, the use of a

strong monochromatic filter will help performance by reducing the

amount of chromatic aberration. Having said all this, it is quite

surprising how good some of the convertible designs are. And the

weight savings are considerable, a boon if you backpack. Cheers, DJ.

As the previous response states, Dagors are not really convertible.

Although, they were sometimes advertised as such, the individual

cells are not fully corrected for coma. As a result, the individual

cells of a Dagor have to be stopped down considerably to produce a

reasonable image. Cheers, DJ.

Generally, lenses designed as convertibles owuld have these marked as

two (or three) aperture scales. If this is missing, you can calculate

them by calculating the actual physical size of the aperture. So if

the combined lens was a 150mm at f/5.6 wide open, that means wide

open, the physical size of the aperture is 150/5.6. No, if you know

what your converted length is, you can calculate the f stop. For

e.g., if it converts to a 240mm lens by removing the front element,

then you know the physical size of the aperture wide open = 150/5.6

i.e., approximately 26.8mm. Divide your new focal length i.e., 240 by

this number and you have your f stop i.e., 240/28.6 which make for

approximately 8.4 i.e., the f stop is approximately f/8.4 (a little

slower than f/8).

Hope this hlps. Cheers, DJ.

Actually, every compensating development technique I know relies on

controlled exhaustion as the mechanism. That is, you want the

developer to exhaust in the highlights but keep working in the

shadows. Its also a good idea to distinguish between using a

developer that is 'in a state of exhaustion' from using a

developer 'to exhaustion'. The former typically refers to using a

developer one-shot but the developer is compounded to be in a state

of exhaustion (a good example is POTA - it is in a state of

exhaustion from the moment it is compounded). The latter refers

typically to reusing a developer till it reaches exhaustion. The

latter is problematic for ensuring consistency because the

composition of the developer changes in addition to its getting

exhausted (repeated development adds bromide to the solution etc

which is likely to affect speed in addition to the maximum density

obtainable etc). OK, that's my pedantry fix for this morning. Cheers,

DJ.

Forgot to add. Re an advantage of DBI (for me, at any rate), I find

that regardless of all the testing that I do, I will always

eventually run into a subject where my prior testing does not give me

a direct answer. Whether this is because I want to change curve shape

by varying agitation and/or dilution etc etc etc is moot. DBI affords

me some control in novel situations (OK, so maybe its an illusion but

what isn't?), and dare I suggest that one should strive to encounter

novel situations.... OK, I'm really off my soap box now. Cheers, DJ

I think Michael's use of a metronome is for timing print exposure,

not print development. I suspect folks are looking at this as a DBI

vs time/temp argument, which I don't think is really accurate. I

think we are talking about combining the two - you still need some

idea about time to decide when to inspect. If nothing else,

inspection allows you to take one last look at the negative before

the point of no return i.e., dropping it into the fix.

<p>

The point is it costs you nothing. If you used only time/temp, you

would just move from the dev to stop and fix. With DBI, you could

drop the film into a water bath stop, inspect to ensure everything is

OK and then move onto the fix. If some more development is called

for, you move back to the dev. (Sidebar: I suspect all those 'blasted

XTOL failures could have been salvaged if the folks DBI'd - again,

not an argument for using outdated chemicals etc etc etc - just a

precaution and acknowledgement that we live in a world teeming with

hobgoblins, gremlins and trolls). As you get more comfortable with

the technique, you can always check at about the 2/3 point in time to

make sure the process seems to be on track. And for those who appear

to insist that this is somehow less precise, how can it be? You're

using it on top of time/temp. And if it is base+fog you're worried

about - I've tested this under a densitometer and found no

statistically significant increase in base+fog, except when using

continuous inspection (Caveats: this did not test all film-developer

combos, and while pyro tans and reduces the sensitivity of the

emulsion further and therefore is often preferred by DBI'ers, I

checked a tanning dev as well as D23). I'm not for a minute

suggesting that DBI is the only way to go, but to imply that it is

somehow less precise is mis-stating the case. Also, from a tongue in

cheek philosophy of science perspective, if no evidence has been

presented for the advantages of DBI, no evidence has been presented

for its disadvantages either... :-)

<p>

Like I said, give it a try, folks. You may decide it adds nothing to

the way you are doing stuff now. Then again, you may decide

otherwise.... Cheers, DJ

Actually, the contrast tends to vary with the color of the exposing

light. Most conventional emulsions tend to gain about the equivalent

of an N+1 level of contrast when exposed through a deep red filter.

Interestingly, Kachel reported the reverse with T grain films, a

lower contrast when exposed through a deep red filter. I've never

seen an explanation for this effect but it is worth controlling for

in developing if you expose through deep colored filters.

<p>

In response to your question, many photographers like rating their

film a bit slower and pulling development a little. This moves the

shadows off the toe and provides better local contrast in the

shadows. Cheers, DJ

Actually, the only reasonably reliable way I have found of putting a

shoulder on the film is to reduce agitation - dilution etc on their

own have never seemed to help in tests I have done. However, I must

concur that the difference between continuous agitation and the usual

(once every minute) does not change curve shape appreciably. I

attribute this to the fact that most developers are reasonably

powerful and so do not really exhaust appreciably in the highlights

within 1 minute. I have found greatly reduced agitation (along the

lines of once every third minute) does put a significant shoulder on

the curve. Typically, this also has to be combined with increased

dilutions for two reasons. One, since agitation is reduced, you want

a long development time to ensure reasonably uniform development.

Two, the increased dilution increases the rate of exhaustion in the

highlights, the basis of the compensation mechanism. Other than this

technique, I've found changing the curve shape for any film-developer

combination to be remarkably difficult to do. Especially problematic

is trying to get a long toe and increased contrast in the highlights -

the only feasible method there seems to be using a staining

developer, ideally with a long toe film. Cheers, DJ.

I've developed lith film with good luck using two developers - D23

diluted 1:3 and a variant of T/O XDR-4 published by Anchell and Troop

called TDLC-3. D23 stock utilizes 7.5 gms of metol and 100gms of

sulfite in 1 litre of water. TDLC-3 utilizes 1 gm of metol, 5 gms of

sulfite and 10gms of sodium bicarbonate in a litre of water. POTA

should work well with these kinds of films (althought I've heard

people complain about streaking). Good luck, DJ.

The general consensus seems to be that differences between cold

lights and condensors are minimal once your negatives are tailored

for the light source.

<p>

1/ I haven't used a Beseler but the answer should be 'yes'. A V54

should work fine with your Beseler and will work fine with VC papers.

Older cold lights had a minor problem with VC papers. Their light was

too blue heavy (VC filters were probably calibrated to tungsten

sources). So, the contrast was often higher than what one would

expect from the filter number. This could be compensated for by some

calibration but the second problem was that older cold lights put out

very little green light, thus making it very difficult to get the

lowest contrasts from the VC paper i.e., the problem is one of

efficiency - if you wanted to print using green light, the cold

light was inefficient, most of the light was wasted, and it is too

efficient in thee blue region (since the calibration of the filters

was to tungsten sources). The V54 is supposed to be optimized for VC

(which probably means it emits well into the green and probably has

efficiencies matched). Anchell says he was very impressed with it.

<p>

2/ Variable contrast cold light heads obviate using filters. You have

two tubes, one emitting blue light and one emitting green light and

you mix these lights to get the contrast you want. So, split

filtering is still done through two exposures but you can change the

setting at a dial and avoid jiggling the enlarger head or lens stage

etc. I'm sure they are very easy to use but they have always been too

pricey for my blood (but then heck, I haven't even sprung for a V54,

I continue with the old W45 tube or whatever is in cold light head).

<p>

Cheers, DJ

Hi Pete, I've DBI'd with a desensitizing bath (Pinakryptol yellow),

although I do not use it routinely. Even with the desensitizer, I

don't keep the safelight on because I prefer saving my dark vision. I

also have to add that when I first started DBI, I didn't have a green

safelight, so I actually used the green light from my Timex (this was

sans desensitizer). I was curious and read the base + fog density on

the densitometer - it was normal. Extended exposure to the light

(read as about one third - half of the developing time) did increase

b+f by about 0.1. Not to suggest you should do things that way but

the method does seem to be fairly robust. Cheers, DJ.

Well, as long as you get the results you want, its all a black art

anyway, even tossing things into a black box and watching it turn for

7'32". I develop by inspection - I got into it after developing some

8x10 lith film. For me, it is one final check to make sure the neg

looks ok before tossing it into the fix. I agree that it takes a bit

of time to develop an eye to estimate densities but it really is

surprising how quick your eye is to develop a sensitivity to the

densities. Its also genuinely surprising how easy DBI is. And I do

own a densitometer and I do run step wedges under it from time to

time. And yet DBI appeals... go figure! I do think its worth a try,

folks. Its saved at least a couple of negatives for me.

<p>

And this may not be something that appeals to everyone, but I do

think there is something to the idea of reducing instrumentation that

could come between you and the subject/process/whatever. I noticed

some time ago that I was so dependent on the exposure meter that I

was not being sensitive or attentive to what I was seeing. OK, I

haven't thrown away my spotmeter but I estimate exposure these days

before pulling out the meter and it is surprising how close I can

get. And, at least for me, it allows me to be more sensitive to the

subject.

<p>

FWIW, IMHO, YMMY, yadda yadda yadda..... DJ

1) The streaking is typically the result of byproducts due to

oxidation. The easiest way to try and deal with this is to use a

sulfite bath instead of a plain water bath i.e., just add some sodium

sulfite to your water bath.

<p>

2) Yes, the general consensus seems to be that modern emulsions are

too thin to work well with water bath development. The trouble is

that the emulsion does not hold enough developer, so while the

highlight compensation works, there isn't enough developer in the

emulsion to develop the shadows more fully. Some folks have suggested

repeated water baths as a way to combat this problem. I've had good

luck with the 2 bath development process where I use D23 as bath 1

and a metaborate accelerator as bath 2. I often dilute bath 1 if I

want greater compensation. Another option is to use compensating

formulae such as highly dilute HC110 or Rodinal with highly reeduced

agitation. You can also try specially formulated low contrast

developers. A document developer like Technidol or a phenidone-glycin

formulae might help. The first thing I would try though is to

increase my exposure i.e., that will move your shadows off the toe

and place it on a slightly higher contrast area of the curve.

<p>

It is also worth noting that the problem you are talking about is

unavoidable. Any N- development develops the film to a lower

contrast. That has 2 implications. One, your paper (which has a

certain scale i.e., can accomodate a certain density range) can now

hold a longer subject luminance range. Two, it will reduce local

contrast in your print (local contrast is resposible for texture).

The second problem is what you appear to be referring to. Highlight

blocking was a problem in films in the past where the characteristic

curve would just shoulder off i.e., changes in exposure yielded no

local contrast in these areas. It is less of an issue with todays

films where the films can build considerable density before

shouldering off. The biggest issue with todays films is ensuring the

shadows have sufficient local contrast i.e., what we want is to put a

shoulder on the film without affecting the shadows. I've had trouble

putting a shoulder onto some films - they often seem to call for

heroic measures. I've come to the conclusion that what works best (at

least with the films I've settled with) is use of a dilute deveoper

(something like a very dilute HC110 or Rodinal), lenghtened time,

highly reduced agitation coupled with increased exposure to support

the shadows.

<p>

I should also add that a lot depends on the way you visualize a

print. Some pictures seem to call for the opposite approach (with low

local contrast in the shadows and high contrast in the highlights) -

only you can decide what the look you want is. Most folks who shoot

landscapes seem to prefer a curve that provides 'open, luminous

shadows' (I interpret that as enough local contrast to provide

texture which makes it look like there is enough light there instead

of Stygian shadows) and are quite happy with a shoulder that reduces

the local contrast in the highlights. Its complicated because it also

depends upon the distribution of local contrast in your scene - I

don't think instrumentation helps here, one needs to develop an eye.

Like I said, depends on your vision.

<p>

Cheers, DJ.

Ditto on above concerns. Pinholes often reveal and conceal themselves

and become larger or smaller as you use movements and stretch or

sompress the bellows. If you're still not convinced, I can assure you

from personal experience that coming back from a 5000 mile trip

across the country to find at least a third of the images fogged and

streaked does not make for a sunny disposition. Cheers, DJ.

That sounds interesting. I don't know if it solves all problems

because we have something of a basic problem with N- developments.

Eventually, when we deal with extremely long luminance ranges, the

paper is unable to accomodate the entire luminance range. Thus, our

attempts at all kinds of measures to try and get the neg to

print 'normally', whatever that is. But the problem is that if you

have a luminance range longer than the papers luminance range, its

problematic. Note I'm not talking about the exposure scale of the

paper - I'm talking about Dmin to Dmax of the paper - if we say about

2.1 density units, thats about 7 stops. If your subject luminance

range is more than 7 stops, you will lose something at one end or the

other. So, we try various measures to try and get everything in, but

that raises the other bugbear. The only way we can accomodate a

longer subject luminance range with the paper is by reducing the

local contrast in some area or the other (lower slope to the transfer

function). Depending on the approach taken, typically we either get

muddy highlights or muddy shadows. If one is able to drop the slope

of the curve uniformly, one presumably loses local contrast uniformly

across the whole scale, although I think that's preferable to losing

an excessive amount at one end. DJ

I think Ryuji has hit the nail on the head. Sharpness in development

refers to adjacency effects. Adjacency effects rely upon a controlled

decomposition of the developing agent. PQ combinations are more

superadditive than MQ combinations. Since Phenidone is so effectively

regenrated by Hydroquinone, the exhaustion rate is vastly lower,

which probably accounts for the proposed lower sharpness i.e., no

local exhaustion takes place. The trouble is phenidone on its own as

the sole developing agent is problematic. It doesn't keep very well

and produces very low contrast - POTA, a developer to provide

pictorial gradation from document film, is a phenidone only developer

that takes advantage of this property but otherwise for normal film,

phenidone only developers are typically unusable. An advantage

phenidone does provide is that it is said to provide a genuine speed

increase of about half a stop (this parallels my experience). I've

used a fair bit of Mytol, a phenidone - ascorbic acid developer.

There is an increase in speed and apparent sharpness over other

solvent developers like D23 but I haven't seen the adjacency effects

provided by an adjacency developer like Rodinal or FX2 (but keep in

mind that this is my subjective opinion).

Single developing agent formulae are the ones that give us a good

idea about individual developing agents. Once you start combining

developing agents, the interactions between them can provide very

different effects from the individual agents themselves. Cheers, DJ.

I agree - it causes confusion. Typically, in photography 1:3 means 1

part of whatever is being diluted and 3 parts of the solvent (i.e.,

you end up with 4 parts of final solution). Richard Henry suggested

using 1+3 etc as a less confusing alternative but old habits die

hard, I guess.... Cheers, DJ.

That's why it is recommended that you use the blue channel of a

densitometer. If you use a regular B&W densitometer, it reads only

the silver image. The silver image is of a lower density since part

of the density comes from the stain. By using the blue channel, you

measure how much of blue light makes it through the negative (density

+ stain) since the stain effectively blocks blue light that the paper

is sensitive to. Cheers, DJ.

Most developing agents require an alkaline environment to be able to

operate (amidol is the one exception that proves the above rule). A

stop bath like acetic acid changes the pH in the print to acidic very

quickly and basically arrests development very rapidly. In addition,

by neutralizing the developer, it is supposed to extend the life of

the fixer (since the fixer does not have to neutralize the

developer). Having said that, a water rinse works very well too - its

just not a sudden stop the way an acidic stop bath is. Water dilutes

the developer a lot pretty quickly but since the pH is probably

neutral or mildly alkaline, there probably is some additional

activity which will continue to take place. There are reasons you

might prefer one or the other. Typically, a lot more folks seem to

use a plain water stop in film development. With paper development,

most people seem to prefer the acid stop. However, there are some

folks who use a water stop even for paper (as long as you are

consistent, you won't go too wrong since the marginal additional

activity in the water stop bath can be adjusted by pulling the print

from the dev just a smidgin earlier). Note that the most important

criterion is how quickly you need to stop development. In lith

printing, for example, you are developing by inspection and need to

arrest development very rapidly (since we are talking about

infectious development there). So, there's no way around an acid stop

bath there. Good luck, DJ.