Making enlargements - how long & how do I know?

Discussion in 'Enlarging' started by BWGirl, Aug 28, 2004.

  1. BWGirl

    BWGirl Member

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    I just got my photo from a fellow APUGer as part of the recent negative exchange. He sent a very detailed explanation of what he did when he made the enlargement (for which I am extremely grateful). But it got me to thinking (a dangerous activity at best)...

    What determines how long you expose a negative for when making a print? Does fiber-based paper need a longer exposure than RC?? How do you know when you should maybe open the lens up a stop and reduce the time of the exposure?

    This was a great exercise! I hope my 'print partner' will not be worried now that he knows I'm full of all these questions! haha :D

    Jeanette
     
  2. Donald Miller

    Donald Miller Member

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    Jeanette,

    Thanks for posting this because I now understand your question. The exposure time is determined by the length of time that is necessary to give the desired tonal representation in the highlight areas of the print.

    This is typically done with a test strip with increments of increasing exposure. I place a strip of paper that I have cut down across the projected image on the easel. I then give increments of exposure by exposing the paper while incrementally uncovering portions of the unexposed paper strip.

    The shadow areas are controlled by the contrast filtration or paper grade that one uses. If the shadows are weak the filtration is increased or the paper grade (in the case of graded paper) is increased. If the shadows are too dark and lacking in detail then the filtration and or paper grade is decreased.

    Insofar as adjusting enlarger lens aperture...I try to hold my exposure time to no more then 25-40 second time and no shorter then 12 seconds. This is to provide time to burn and dodge the print in whatever way is required. I have at times had negatives that required longer times and I have at times had exposure times below 12 seconds when no burning or dodging is required.

    Re fiber and RC paper exposure times...someone else will need to answer that since I haven't used RC paper in over twenty years.

    Hope that this answers your question.

     
  3. wfwhitaker

    wfwhitaker Member

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    Jeanette,

    The short answer is that it's determined empirically, i.e., by trial and error. Exposure is usually dictated by the high values of the print. Low print values (shadows or dark areas) usually are set by choice of contrast grade (either the paper grade or, in variable contrast printing, the printing filter). Most people make a test strip on which successive exposures are incrementally longer (darker). There are other methods.

    Your best bet would be to start with a good book on the subject of printing, of which there are many. I've heard good things from knowledgeable folks about The Ansel Adams Guide : Basic Techniques of Photography - Book 1 by John P. Schaefer, but haven't seen it myself. Most any edition of the original Ansel Adams series would be good for basics and should be at your public library. Personally I like Way Beyond Monochrome by Lambrecht and Woodhouse, but it may be a little technical if you're just getting started. Others will have good suggestions, I'm sure.

    -Will
     
  4. wfwhitaker

    wfwhitaker Member

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    Don's post was seconds before mine. Sniped again! :smile:

    -Will
     
  5. Donald Miller

    Donald Miller Member

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    That is one of the few benefits of a life misspent on Ebay...my kids are becoming resentful at not having an inheritance to look forward to.

     
  6. VoidoidRamone

    VoidoidRamone Subscriber

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    Here's basically what I do to determine exposure... after getting the negative focused, etc. Cut a piece of photo paper in strips, I'd go with strips approx. 2"x8", so you can get 5 strips per 8x10 sheet. Then place a strip on the easel and get a piece of opaque matboard or something of that sort. Set your timer for about 3 seconds, cover all but about 1-2" of the strip with the matboard and expose the paper... then repeat until the entire strip has been exposed, moving the mat board 1-2" each time and exposing for about 3 sec each time (remember to keep it constant for each strip)... then develop the strip, and look at which area is the "correct exposure". If the whole strip is too light, do the same steps except expose the whole strip for something like 10 or 20 seconds before.

    Also I tend to make my first prints (work prints) with a relatively low grade of contrast and move up from there... I'm not sure about the difference of exposures for FB and RC, but I do know that you can get higher contrast on FB if you use a larger aperture... this is not as drastic an effect with RC. Also remember to account for drying down with FB, when FB paper dries it tends to be about 10% darker. Also, like Donald, I try to keep my exposures around 30 seconds, for dodging and burning.

    Hope this all helps, good luck. -Grant
     
  7. photomc

    photomc Member

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    Jeannette,

    Donald covered most of your question perfectly, like he always does. Here is what I know about RC vs Fiber, with Ilford MGVI my times do not change when everything else is the same. I use the same exposure for fiber that I use for RC (have been using up my stock of RC for test prints). Now, if you change paper, say from MGIV to MGWT that is a different story, my experience with MGWT is it is a much slower paper. The first time I noticed this, I posted a question too! All I really had to do was read the package insert that came with the paper.
    That said not all of the paper I have tried recently has had a package insert - but most info is available via a web site.

    Good luck...BTW Donald, Thanks for reminding me I need to start cutting up my paper into strips for these test - cuts down on the waste, plus saves paper and money.
     
  8. Nige

    Nige Subscriber

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    yes, the info sheet that comes with the paper usually has a speed rating, usually by filter value (drop in filters, not colour head settings). In theory if the numbers are the same, you should be able to expose the same for RC and FB versions, however I think it's a guide only, as I've found them not to be directly equivalent, I think it's probably a number of factors, the paper itself, how it reacts to the developer and the dry down affect.
     
  9. photomc

    photomc Member

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    Nige, you are correct of course - as with most of what we do, it is a guide only. Light source, filters (and age of filters), plus our own darkroom habits can be a factor.
     
  10. noseoil

    noseoil Member

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    Jeanette, there is another way of exposing, but the rest has been well covered by previous posts. If you decide that a 20 second exposure (just to pick a number) is about what you feel comfortable working with in an image, try setting your timer at 20 seconds and then vary the f-stop instead of the time. Assuming your setup is already correct with respect to focus, crop, etc, a change in stops will enable you to see the relationship in tones you need fairly quickly.

    If, for example, you have a portrait you are working with and know the values for highlights you want, work that area initially and get the exposure you need for that portion. If the rest of your technique is correct (film speed, exposure, development, lighting, etc.) the print will be very close and you will just have to do a bit of fine tuning to get it to work. This is just another method of doing a print, but you might give it a try.
     
  11. Dave Miller

    Dave Miller Member

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    I going to suggest two things without any great explaination, but trust me!
    1) Invest in a copy of Tim Rudman's book "The Photographer's Master Printing Course". May be out of print, but copies come up often on Ebay.
    2) Take time to get your head around "f stop printing".
    3) Use RC paper until you know what you are doing.
    Yes, I know that's three, got carried away.
     
  12. Dave Miller

    Dave Miller Member

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  13. rogueish

    rogueish Member

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    time diff. for Rc vs FB

    I have found that Kodak's Polymax Fine Art Glossy double Weight FB paper required 1-2 secounds more exposure than Ilford's MGD RC paper (8x10@f8, grade 3 filter same negative, same crop). Agfa's multi contrast semi matt classic FB required about the same as Ilford's multigrade matt FB (11x14@f5.6 grade 2.5 filter).
    Just picked up some Bregger 11x14 museum weight. got 10 sheets just to try and I have the just the neg for it... :D
     
    Last edited by a moderator: Aug 29, 2004
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  15. dr bob

    dr bob Member

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    Do what Don says. After a short time you will have the necessary skill (knowledge) to cut the experimental time down. I now forget the strip technique and just rip an 8x10 sheet of the paper of interest into quarters (I think others here, Aggie maybe, do this as well) placing the torn sheet in a critical spot in the projected image as an initial test. When satisfied with the exposure settings, do a full sheet without manipulation. I write all over this print, after drying of course, indicating areas to be dodged and burned in the “final” print – it “ain’t never” the final print though.
     
  16. Bob Wagner

    Bob Wagner Member

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    Two minor points:
    Hope this isn't too simple, don't know how much you've done in the darkroom...
    Make sure you don't allow the test strip to move when you move the cardboard or whatever you use to progressively uncover it.
    You might try a little tool Kodak makes that is basically a circle of plastic that has varying degrees of opacity (think neutral density filters), (called something like a 'test print xxx' ?). You lay it on top of the paper and expose for 1 minute. The varying degrees of opacity let a predetermined amount of light expose the paper. When developed and at least partially fixed turn the lights on and pick the best looking wedge and note that there is a number between about 2 and 60 printed right on your test paper indicating the correct number of seconds for the exposure. (You can also use 30 seconds and halve the indicated seconds)
    This explanation is twice as difficult as actually doing it and as I recall the instructions that come with it are easy to follow, it's also very cheap. I even use it when I'm doing a big enlargement to get approximate exposure times for dodging and burning in various areas. When I'm really on the ball I note the f stop and enlargement size on the back and save the test strip for future duplication or trying out differnet interpretations of the same negative
     
  17. BWGirl

    BWGirl Member

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    Thanks for all the info! I always know I'll get a good solid explanation here & I cannot tell you how much I've learned since joining this site (that's why it says Subscriber by my name!) :D

    I've used one of those plastic things. I like it much better than the expose-move cardboard-expose method. I've pretty much got a handle on printing as far as exposure, dodging & burning.... I continue to refine my technique in these areas. I had just wondered about why it might be better to do a longer exposure at a more "closed" f/stop. I think I will be doing some experiments with a print to see how this may affect my final result.
    Dr. Bob.... you know... I should be doing this. I am going to make an effort... I am so darned ADD sometimes!!! :tongue: Patience! Patience!

    Thanks again, everyone!
    Jeanette
     
  18. eheldreth

    eheldreth Member

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    Kodak Projection Print Scale

    I am new to darkroom work, and have found the projection print scale bob mentioned vary useful. It is fairly accurate and worth the $12 from B&H. Mine is an older one that was given to me but I think the Kodak R-26 Projection Print Scale is the newer version. Delta also makes a project print scale. And I have a Paterson test strip printer, which I find to be to clumsy. The paterson unit works off the same idea as the paper strips but uses a series of plastic strips which are hinged and lay down in sequence over a piece of 4X5 paper. I like to do my exposures with the lens stepped down because it gives me a broader range of densities, expesually when the negative is very light.
     
  19. jon koss

    jon koss Subscriber

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    >>What determines how long you expose a negative for when making a >>print? Does fiber-based paper need a longer exposure than RC?? How >>do you know when you should maybe open the lens up a stop and >>reduce the time of the exposure?

    There is a somewhat repeatable approach that may be of use to you.

    You will need two negatives. One is the one you wish to enlarge. The other is just a blank frame from the same roll. There are usually a couple of blank frames after the last exposure on the roll.

    First, adjust your enlarger up and down to get the size print that you want. Then put the image neg in the carrier and focus the image. (A grain focuser is worth its weight in gold. They cost little and will make your prints sharper.)

    Second, remove the image neg from the carrier and replace it with the blank frame. Obviously, take care not to disturb focus, etc.

    Now, with the blank frame in the carrier, make a test strip as described earlier. Start with the lens two stops closed down from max aperture. Just lay the strip of paper in the easel and expose it in half-inch segments. Each exposure should be the same amount of time - say, three seconds. (A good timer is as valuable as the grain focuser.) Twelve or thirteen segments should be more than enough. You will then have a test strip with one segment that has seen three seconds of exposure, next to a segment that has six seconds, then nine and so on up the line. Develop the test strip.

    Here is the best part: look carefully at the dried test strip. You will see that it gets progressively darker for several steps. Then it stops getting darker no matter how much more light hits it!! For instance, you might find that there are eight segments that darken progressively, but the ninth is no darker than the eighth and the tenth no darker than the ninth or the eighth. Thus after 24 seconds (eight pops at three seconds each) the darkest tones in the print will get no darker regardless of how much additional exposure they receive. This hugely useful piece of info is "the minimum time to maximum black" for the combination of negative, paper, print size, etc that you are using.

    Now comes the fun. Remove the blank frame from the neg carrier and replace it with the image you wish to enlarge. Give this neg the exact same exposure that you needed to reach max black (in our example, 8 pops at 3 seconds = 24 seconds). Use grade 2 contrast. The resulting print will show what you neg is really like. If everything is muddy and you find yourself reflexively reaching for grade 4, then the neg is not exposed and/or developed correctly. If everything is crying to be burned-in, then the neg is too hot.

    If your prints never look anywhere near decent using this "min time to max black" test then you should consider modifying your film exposures and/or your film development times. Ideally grade 2 will handle most negs and the soft or hard stuff will be for special effects.

    If all this sounds like a pain, consider this: I ran one test strip last night before printing a new neg that had never been enlarged. I printed at my "min time to max black" setting and the very first print was frame ready - no muss, no fuss, no guessing about anything at all. In the end, it will save paper and time so you can shoot more!!

    Hope this helps. It is just my solution - not a prescription for world peace. Any and all corrections, comments and criticisms are welcome.

    Enjoy,
    Jon
     
  20. mark

    mark Member

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    I totally second Jon's method. It's how I worked when I needed to get a large number of prints done for an order or a book while working the NAU archives. But I never thought of doing it for my own personal work. There I trusted my eyes and the mood I was in.
     
  21. BWGirl

    BWGirl Member

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    Jon,
    Thanks so much! That is just the sort of thing I have been looking for! I'm going to give it a shot!
    Jeanette

    PS - I've read about the 'maximum' black ideal, but this is the first time I've seen it explained in a way that made totally clear sense!
     
  22. wdemere

    wdemere Member

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    See http://www.barry-thornton.co.uk/unzone.htm for a similar approach that works very well. One of his better points is that people don't see dark greys as well as light greys (which includes the observation that one stop darker than the first perceptible change from black is zone IX - not necessarily the same thing as the max black that the paper is capable of producing.) And, also that most negatives are under-exposed and over-developed.

    Check out everything on his site. It is time well spent.

    Good luck,

    William
     
  23. jon koss

    jon koss Subscriber

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    Hi Jeanette - Did you get a chance to try some straight prints at min-time-to-max-black settings? If so, any impressions?

    Jon
     
  24. BWGirl

    BWGirl Member

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    Hi Jon!
    Unfortunately, the yard was calling my name...I usually stuff cotton in my ears and race for the darkroom, but I was not quick enough this time. I plan to do it on Tuesday (Monday...alas...I must plant some grass...no; the legal kind!) haha :D
    I will report back on what I discover!
    Thanks!
    Jeanette
     
  25. bazz8

    bazz8 Member

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    making enlargements how long?

    My exact question several years ago the test strip method was to me
    so long winded and when a elderly b+w printer suggested the Kodak print scale then the answer must be 60 sec.
    simply focus the lens wide open stop down a stop or two
    select grade
    lay scale on top of the paper ready to expose
    or in my case 2 scales 1 on the main subject the other on sky
    in portrait mode 1 on the facial area the other on the background
    expose,dev,stop,fix,dry
    select the best tonal wedge and there is the starting exposure you can
    then use a patterson 5 fingured test strip to get the very best out of the neg, to be honest very seldom do I need to use the patterson unit at all
    simply using the in between time by eye.
    I you use a processor like me then my chemicals last up to 2 weeks gradually
    going off with this method using the print scale the processor takes 60-70 sec wet to dry and no allowance for drying comes in to consideration.
    Just my opinion but any method will work but why complicate the process
    and since using this method my competition prints have won the last 2 yearly
    aggregate trophys in the club that I am a member of.
    regards
    Barry Treleaven
     
  26. inthedark

    inthedark Member

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    After reading this thread, I am concerned with the max black concept. Now I only print and am not a photographer, so I don't get a choice as to what to print. But here is the thing. Different negatives from the same roll will print differently (especially color negs), so I am a bit confused as to how using the blank at the end of the roll will get you anything but closer to the correct exposure.