Opinions are like... (Rating B&W film speeds)

[JHannon]

Have a look here: Dead Link Removed



Steve.

I'm glad that site is still around. I really liked his articles.

 

[optique]

More than one lens, more than one EI

First, Apug is a fantastic site, with great posters and a huge source of info. Great work.

I assume that when one picks a personal EI, that is likely specific for one camera/lens/chemical combination, right?

For instance, I am a new MF RB67 photographer, with multiple lens, shooting mainly Tri-x, dev in d76. Since they are all leaf shuttered, wouldn't I need to determine my personal EI on a lens by lens basis too?

I guess what I am getting it, is it typical that there is enough variability between lens (on the same body) that this exercise would be warranted? Maybe not. Don't know.



Comments?
TIA
Steve.

 

[Peter De Smidt]

For instance, I am a new MF RB67 photographer, with multiple lens, shooting mainly Tri-x, dev in d76. Since they are all leaf shuttered, wouldn't I need to determine my personal EI on a lens by lens basis too?

Steve.

It all depends how variable the shutters are. In general, they shouldn't be so variable as to cause you big problems. It is one reason, among many, to err on the side of giving lots of exposure with BW negatives. That way, even when the shutter gives a faster than average shutter speed, you'll still get good shadow separation. On the times when the shutter speed is slower than average, you just get a little more exposure, and current films have tremendous latitude for increased exposure.

 

[David A. Goldfarb]

I guess what I am getting it, is it typical that there is enough variability between lens (on the same body) that this exercise would be warranted? Maybe not. Don't know.



Comments?
TIA
Steve.

If you wanted to be extremely thorough, you could do this, but it's better just to test your lenses and either know their actual shutter speeds or keep them all in good repair, so they will be within acceptable tolerances.

Calumet sells a shutter speed tester, or you could make some tests on film.

 

[Leon]

First, Apug is a fantastic site, with great posters and a huge source of info. Great work.

I assume that when one picks a personal EI, that is likely specific for one camera/lens/chemical combination, right?

For instance, I am a new MF RB67 photographer, with multiple lens, shooting mainly Tri-x, dev in d76. Since they are all leaf shuttered, wouldn't I need to determine my personal EI on a lens by lens basis too?

I guess what I am getting it, is it typical that there is enough variability between lens (on the same body) that this exercise would be warranted? Maybe not. Don't know.



Comments?
TIA
Steve.

if your lenses shutters are not calibrated then you might want to think about testing for each one as it could provide a variable .... but life's too short! I always test a new film/ developer combination using my main camera with standard lens based on printing at grade 2 - then stick to the results of that (invariably manufacturers film speed) - then any negatives on a roll which do not print well at grade 2 (there is ALWAYS at least one on a roll that was taken in less than ideal conditions), I'll use different printing grades/ techniques to deal with them. If I am concerned about shadow detail for a particular shot, I'll give about 1 stop extra exposure to make sure I record what I need on the film. testing endlessly just distracts from getting on with being creative, IMO.

 

[Steve Smith]

For instance, I am a new MF RB67 photographer, with multiple lens, shooting mainly Tri-x, dev in d76. Since they are all leaf shuttered, wouldn't I need to determine my personal EI on a lens by lens basis too?

I guess what I am getting it, is it typical that there is enough variability between lens (on the same body) that this exercise would be warranted? Maybe not. Don't know.

There are two sides to this. The first one is what you are refering to. i.e. matching your personal film speed to variables such as incorrect shutter speeds and apertures, light meters which are not quite right and even differences in the way people meter a scene. The second point is that some people prefer the look of a film exposed at something other than maufacturer's rated speed.

I am also a multi-lens RB67 owner and I trust that the shutters and apertures on my lenses are accurate to a much greater precision than my abilities with a light meter so I wouldn't do personal tests with every lens.

In fact, if you read my earlier posts, I admitted that I didn't actually do any tests! I just followed what a lot of people seemed to be doing and decided that I liked the results.

Steve.

 

[DeanC]

Calumet sells a shutter speed tester, or you could make some tests on film.

Although, I read recently in another thread that the manufacturer has discontinued it...

 

[Bob Carnie]

This is a very good thread with advice from some very knowledgeble folks. This thread to me is what APUG is all about. If Sean can bottle the magic wisdom given here and apply it to all topics what a resource. thanks to the OP for continuing to ask, and thanks to the others for clear ,and level headed answers.

 

[Neal]

Dear smo2,

I suggest some light reading. "The Negative" (Ansel Adams, easy to find) and "Perfect Exposure" (Roger Hickes and Frances Shults, Amazon.com) are two good places to start. I think the latter might be a bit more specific to your questions.

Neal Wydra

 

[Mahler_one]

With the most respect, you are asking technical questions that must be answered with information that assumes you know some basic concepts concerning film curves, brightness ranges, etc. By reading a book such as "Beyond the Zone System" by Davis you will be able to know what the toe of a film curve is. The book is simple to understand, and comprehensive enough in approach so that you will even be able to grasp what advantages are to be gained from running your own film curves! Moreover, if you decide to "do" your own film curves most of us can even tell you where to get such tests done economically, and quickly.

Best of luck to you, and let us know how you are doing.

Edwin

 

[jim appleyard]

One of the best explanations of film speed/ISO/exposure can be found here:http://rogerandfrances.com/

Go to the chapter on ISO Speeds.

Lots of other good info as well.

 

[Roger Hicks]

One of the best explanations of film speed/ISO/exposure can be found here:http://rogerandfrances.com/

Go to the chapter on ISO Speeds.

Dear Jim,

Thanks for the kind words. Now I've found out how to post direct links, thanks to kind help from people here on APUG, here it is:

http://www.rogerandfrances.com/photoschool/ps iso speeds.html

There are internal links there to things like gamma, density and the H&D curve.

Cheers,

Roger

 

[panastasia]

smo2,

As you read all the advice given you're probably experiencing information overload and that makes the information more difficult to comprehend. It's like trying to solve a complex equation in mathematics. The best way to begin understanding is to break it down to smaller parts, understand each part, and then put all the parts together.

I suggest that you start with the simple rule: "expose for the shadows - develope for the highlights". Do some reading, as suggested, and learn about The Zone System, how to use exposure meters, and then film development, in that order. Then go back and read over what everyone here has told you (they're all explaining the same thing in their own way) and the advice should become clear.

It'll save you allot of time and you'll retain more knowledge in the end with this approach.

Good luck,

Paul

 

[JeffD]

Ok, I haven't read this entire thread, but this is the point where I like to confess that I have to give most black and white films I test an average of 2 stops more exposure (and this is in developers that supposedly give "full" film speed).

I have to rate Ilford FP4+ at 25 to get "proper" exposure. By proper, I mean a zone 1 exposure gives .1 density over film base + fog.

I sometimes feel weird that I have to do this. Maybe my Pentax digital spot meter is in serious need of calibration, or, maybe everyone else are obliviously underexposing their films, and are quite content to do so!

 

[Chuck_P]

I assume that when one picks a personal EI, that is likely specific for one camera/lens/chemical combination, right?

For instance, I am a new MF RB67 photographer, with multiple lens, shooting mainly Tri-x, dev in d76. Since they are all leaf shuttered, wouldn't I need to determine my personal EI on a lens by lens basis too?

No. You do not have to test for personal EI on a lens by lens basis. Test using the lens that you use the most. Use those results for your other lenses, and, if you have done your testing correctly, then in the words of AA himself,

"any variations introduced by a change of equipment (such as the possible difference in aperture calibration or flare introduced by changing lenses) should be quite apparent if they are significant. For a change of film or development, of course, new tests must be conducted".


Chuck

 

[gainer]

The lens is not usually the problem. The shutter speed may vary quite a bit from camera to camera. Latest models probably either work acurately or not at all, but older cameras, even Leicas, have shutters that can be calibrated for a reason. It shouldn't take a very complicated test to show if the shutters and f-stops of your cameras are compatible. Just shoot a sequence of the same subject where each shot is a different combination of f-stop and shutter speed that should give the same exposure.

 

[radiantdarkroom]

trust yourself that is all that is all that is required. Getting bogged down in others opinions well mess you up. As a general rule for easy printing and consistent good prints almost everyone says overexpose 1/3-1 stop. Tasss way easier to print from a slightly over-exposed neg than an underexposed one.

 

[smo2]

Zone System

Thanks for all the good advice - I picked up a copy of The Negative by Ansel Adams. I think I know understand the zone system - although I am not entirely sure how one implements it. The meter I have is a Sekonic L308s - here is the link:

http://www.sekonic.com/products/products.asp?ID=3

Is this a suitable meter to try and implement the Zone System? How does one meter a landscape - take a couple readings and then adjust them mentally for what you see?

Also, in the book he talks about the way different colors are represented in B+W. Any ideas where I can see some pictures of color shots and the same things with B+W film? I had never really considered this before.

Thanks.

 

[JeffD]

Thanks for all the good advice - I picked up a copy of The Negative by Ansel Adams. I think I know understand the zone system - although I am not entirely sure how one implements it. The meter I have is a Sekonic L308s - here is the link:

http://www.sekonic.com/products/products.asp?ID=3

Is this a suitable meter to try and implement the Zone System? How does one meter a landscape - take a couple readings and then adjust them mentally for what you see?

Also, in the book he talks about the way different colors are represented in B+W. Any ideas where I can see some pictures of color shots and the same things with B+W film? I had never really considered this before.

Thanks.

You can use your meter, but many zone heads, myself included, use a "spot" meter. This lets you meter tiny areas of your scene, from one vantage point. You can measure the shadow area, maybe a key midtone, and a highlight. I think the meter you posted averages a much larger area of your scene (averages the differences in shadow and highlight), and makes it a little harder to understand the relative differences in brightness easily. This averaging of values is somewhat contrary to zone system thinking. Most zone thinkers want to know precisely the brightness of an important shadow area, then they adjust their exposure so that this area gets enough exposure to be sufficiently visible on the print. They then measure the highlights, and use this info to alter their developing times. All this is covered in "The Negative". This is one of the sacred texts that St. Ansel handed down to benefit us all. Study and show thyself to be approved. :rolleyes:

I wouldn't get to hung up on colors at this point. Use your meter, and if a part of the image is 1 stop brighter than another, then you could assume that it will portray with a tone that is around twice as bright on your print. (This is not perfectly accurate, as some films and even light meters are slightly more sensitive to some colors than others, etc., but you get the idea)

What you need to understand is, that if you have a red apple, and a green apple on a table, they appear to you to be quite distinct from one another, however, if they read the same in brightness to your lightmeter, then they will probably both print with very similar grey tone on your final print, and much of the distinction will be lost.

Later, you might want to experiment with filters, to make the differences in colors print with greater variances in tone. In the above example, a red filter on the camera lens could assist you in making the red apple appear much lighter on your print, or a green filter would make the green apple appear brighter, etc.

 

[smo2]

Meter?

Any good (but inexpensive) meters out there for that purpose? That explanation makes some sense in the negatives and prints I have been getting.

 

[JeffD]

Any good (but inexpensive) meters out there for that purpose? That explanation makes some sense in the negatives and prints I have been getting.

I don't know what your budget is, but a decent used spotmeter is probably between $100-$200, at least for a Pentax spotmeter. Try typing "spotmeter" in the EBAY search, and see what comes up!