i understand some stuff - get lost when applying...

[cotonetes]

i'm new to darkroom.
help please.

So this is what I do not understand or, what i am having trouble understanding.
i usually work with a 2 filter.
Sometimes (2 times) i've used a 3 filter and have decreased the exposure seconds (or that's what i've done).

I always do a test print, star at a 3 second exposure, 1'' each strip, at f/8.
When the image looks right at 3 seconds or 6, i've been told to increase aperture number and multiple number. That is, if it's 3, and i move to f16, that should be a 12 second exposure (to avoid less than 10s exposure).

Now my questions are the following:
When an image is too bright- do i increase exposure time and increase aperture number? or leave aperture number alone and work on f/8 and only increase time?...
thinking that aperture number lets in half the amount of light..
or do i only increase time?

or
do i change filter number?

When an image is too dark, do i decrease exposure time and increase aperture number?
I'm very confused with how aperture on enlarger/filter/exposure seconds affects how light or dark an image can come out.

At the moment i am working with an image that i tested on a 2 filter, intervals of 1'' , 3 seconds each. the image looked "right" at 9-12 seconds, so i selected 11. Some spots are too dark and others too light, so i dodged some sections and burned others. Some mirrors are pure white. I proceeded to burn the mirrors for 6 seconds, and it's still too white. Should i do 9, 10, 11 seconds on them?

or, am i selecting exposure time incorrectly?

-oh, i understand how increasing aperture number lets in half the amount of light, so i compensate by adding exposure seconds.

 

[winger]

Personally, I think you're making it too difficult - that's way more math than I'd want to do (I'm pretty bad about math anyway). I've learned that with my enlarger, I get decent times for 8x10s if I use f16 (usually). I choose which filter I think I'm going to want - which is frequently #2 or #2 1/2 and I do my test strip at f11 with that filter. I find a time on the test strip that I like the look of and I do a work print (the whole image) at that time. If I don't like the contrast, I change to the filter I think will work and I do a work print - I do not change the time unless I go to a #3 1/2 or higher. If I'm printing on 11x14, usually f11 is good. That part depends on the negs and I have a tendency to underexpose (I'm working on it).

 

[cotonetes]

oh, thank you for answering and recommending your method...

but i'm supposed to follow the order i've mentioned (start with #2, strips of 1'', 3-4 second exposure and move from there...
usually, if the image seems "right" at 3-6 seconds, i've moved to f16 and 12-18 second exposure.

yet with the example i've provided this isn't the case. it "looks" right at 9-12 seconds, f/8, but some parts are too dark, even when they've been dodged.
thank you!

 

[Christopher Walrath]

Welcome to APUG from Yahoo Answers (wink wink). You say some prints are too dark. Are we talking the same neg or different negs here?

 

[Paul Sorensen]

First, remember that the filters are used to control contrast, not exposure. They can cause you to have to change the time and or aperture, but they are not designed for that purpose.

What I generally do is find an appropriate aperture, I will usually start at f16 but might start at f8 or f11 if I am making a larger print. Then, if I decide that the print is a little too light, I will use a little more time rather than larger aperture. I think you are doing the right thing, so I would not worry too much. It is appropriate to stop down to f16 like you are when you are getting print times of 3 to 6 seconds.

If some sections are too dark and some too light, you may need to reduce contrast. It sounds like you have a negative with very high contrast, so the paper can't handle the contrast range of the negative.

BTW, I have found that usually you are advised to burn in areas that are too light rather than trying to dodge the areas that are too dark. It is easier to control adding time and it is usually more forgiving than dodging.

Your negative might be too difficult to print, especially if you are pretty new to this, but my recommendation would be to try a #1 filter, do test strips of the darkest area where you want to have detail and find out that exposure. Next, do the same for the lightest areas where you want detail. Basically, that will give you a base exposure (the time for the dark area) and the amount of burn (the additional amount of time necessary to get detail in the light areas).

One thing you probably want to do before going to all this effort is to take a good look a the negative with a loupe on a light table. Make sure that there is detail in the light and dark areas of the negative. If you the dark areas are completely blocked or the light areas clear, then you are never going to get a totally satisfactory print from it. Basically, if the detail is not on the negative, you will never get it on your print.

Of course, make sure that you are having fun!

Paul

 

[removed account4]

make a darker print
with less contrast
as paul suggests ...

it also might be easier to get the right tone for the mirrors
and dodge the print than burn in the mirrors ...

with certain high contrast negatives i have found it easier
to make part of initial exposure with a less contrast filter,
the rest of the exposure with and burn with a higher-contrast filter.

http://www.lesmcleanphotography.com/articles.php?page=full&article=21

les explains it much better than i ever could !

good luck !
john

 

[JBrunner]

FWIW I find the exposure that gives a true black at the equivalent of a #2 (I print B+W with a color head) and then adjust contrast from there with filtering. If exposure needs to be adjusted after filtering it usually needs more exposure and I do it with more time. I rarely change the stop on my enlarger and keep it stopped enough that too short a printing time isn't usually a factor. If it is I stop down and start over. Changing aperture and time together is a big-ol-can-o-worms. You shouldn't need a slide rule to make a print.

 

[jerry lebens]

You're asking questions that are difficult to answer quickly and easily, there are whole books written about this subject. An exposure of 3 to 6secs is too short to be accurate and, when you multiply it, you will become increasingly inaccurate.

1) During testing don't change two control parameters at once : ie. if you change the contrast, don't alter the aperture or the time. Changing two parameters is confusing.

2) Start with filter G2 contrast filter and, after you've focussed, close the aperture by at least two increments ("stops") and perform a series of 3 or 4sec tests. If your preferred exposure is less than 10 seconds, close the aperture again by one stop and repeat the process. You're trying to achieve an exposure between about 15 and 25 seconds. If, after you've closed down 3 stops, you still aren't between 15 - 25 secs, close the aperture again and test again.

3) If to your eye your test sheets look too contrasty (too black white) decrease the contrast grade to 1.5 and repeat the test process. If the tests look lacking in contrast, (too grey with mushy whites and insipid shadows) increase the contrast to G2.5.

4) When you think you have a strip with the correct exposure and contrast grade, take a note of the time and expose a full work print.

Whilst you're learning, this will be a slow process - learning to judge tones isn't easy. You need a lot of experience to judge tests well. Often, you will return to a print later and realise it wasn't as good as you thought. Just keep trying and you will improve

 

[DLawson]

yet with the example i've provided this isn't the case. it "looks" right at 9-12 seconds, f/8, but some parts are too dark, even when they've been dodged.
thank you!

Ooo, I know that one.

Dodge more.

Some negatives are just difficult that way.

I ran into one of those, or a print from it, just yesterday. I remember working at it, and the satisfaction when it was done.

This was a shot I took in high school -- first floor classroom, girl(friend) in the foreground, window in the background. A straight print of her had her on a white background, like angel artwork. I increased exposure and dodged her face. Then again. Then more (and maybe more again).

The print I have has her backed up by some blurry guys hanging out in the parking lot around a blurry car -- i.e., roughly how a person at the time would have seen it.

[It isn't easy. I think I have the camera vision thing down (somewhat). Printing is still taunting me.]

 

[Ken Nadvornick]

You shouldn't need a slide rule to make a print.

Wow. Been an awfully long time since I saw a reference to one of those. And an awfully longer time since I used one myself...

Ken

 

[JBrunner]

Wow. Been an awfully long time since I saw a reference to one of those. And an awfully longer time since I used one myself...

Ken

Go analog!!