Go Back   Rangefinderforum.com > Cameras / Gear / Photography > Rangefinder Forum > Image Processing: Darkroom / Lightroom / Film

Image Processing: Darkroom / Lightroom / Film Discuss Image processing -- traditional darkoom or digital lightroom here. Notice there are subcategories to narrow down subject matter. .

Reply
 
Thread Tools Search this Thread Display Modes

Converting BW to...um...BW
Old 08-24-2009   #1
remegius
Registered User
 
remegius's Avatar
 
remegius is offline
Join Date: Feb 2008
Location: Rohnert Park, CA
Posts: 293
Converting BW to...um...BW

I'm not sure just what is going on here. I started shooting BW400CN a few days ago, and having it processed with CD at Costco. I noticed when loading the files in Photoshop that they are all RGB files. After doing a little tweaking in PS I printed a couple of files on my 9180 and things just didn't look right. The prints had a bit of a blue color cast, and when I looked carefully at the image on the monitor I could see it there too. On a lark I converted one of the files to grayscale and...voila, I got...grayscale. I'm a little perplexed by all of this. Yes, BW400CN is a C41 film, but even though it has an orange mask like its color cousins, it's still a black and white film. Why should I have to convert the scans that I am getting (good ones, BTW) from Costco to grayscale, when the film itself is black and white to begin with. I'm sure that the answer to all of this is embarrassingly simple but, what the heck, I'm not thin-skinned.

Cheers...

Rem
__________________

Above all else this is the greatest treason, to do the right thing for the wrong reason.
  Reply With Quote

Old 08-24-2009   #2
cweg
Registered User
 
cweg's Avatar
 
cweg is offline
Join Date: Feb 2008
Location: near Hamburg/ Ger
Posts: 234
I use the BW400CN much too. And I always tweak them in "real" BW too, cause the Photolab is treating the BW like any other Colorfilm and is pulling it through its C41- Soup. The results are often a little colored, like the film is not really irrigated enough. Once I chose a really BW- Development at the same Lab, and the Film was developed correctly. No Postprocessing needed, but it cost me a lot of bucks. So I postprocess my Scans myself and save the money for the Lab and take the cheap C41.

So, don't worry
__________________
regards cweg

my pics at flickr http://www.flickr.com/photos/[email protected]/
  Reply With Quote

Old 08-25-2009   #3
peterm1
Registered User
 
peterm1's Avatar
 
peterm1 is offline
Join Date: May 2006
Posts: 5,501
There may be a couple of reasons. The first is that the developing lab is lazy and scans everything as color to save themselves the bother of having to think. The second is that by saving them as color not grayscale files it may give you more options for how you finalise your processing. (Yes I think you need to post process even from scans). So perhaps its not such a bad thing as it does mean you can tweak the images more than you otherwise might be able to. (e.g. if you wished to apply a color overlay effect you need them in color mode.) BTW if you think things are bad when you get scans from BW400CN boy did I ever get some doozies when I received prints in my days before digital. Unless I found a lab that would print on black and white paper or which really trained its staff, I would get blue, sepia, orange - all kinds of casts depending on how the lab set up (or did not set up) its color channels. Most did not know how to do so with this emulsion and that is why I got such dreadful results.
  Reply With Quote

Old 08-25-2009   #4
Michael Da Re
Registered User
 
Michael Da Re is offline
Join Date: Oct 2006
Posts: 240
I believe this was discussed a while back. Seeing how BW400CN is a c-41 film and only colour film is processed with c-41 then that makes it a type of colour film so to speak. I could be wrong but I don't think it can be processed correctly using b/w chemicals. Would that not be cross processing? I used BW400CN for a while until I realized that I could scan and convert the cheaper colour films like Kodak 200 and 400 to b/w and get the same results.

Michael
  Reply With Quote

Old 08-25-2009   #5
mfunnell
Shaken, so blurred
 
mfunnell's Avatar
 
mfunnell is offline
Join Date: Sep 2006
Location: Sydney, Australia
Posts: 2,460
My experience is that a minilab operator who knows what he or she is doing will produce neutral prints and neutral scans (always, in my experience, 8-bit RGB JPEGs). Many will produce "more-or-less" neutral scans, but often prints with rather horrid colour casts (I've mostly seen green and magenta). That's one of the reasons I've moved away from C-41 B&W. When I do use it I have the lab develop the film, not cut the negatives, and not bother with scanning or prints. I do that for myself with much better results.

My primary use for C-41 B&W is when I know I'll need to process things quickly and want to be able to scan using Digital ICE. Otherwise I develop "real" B&W myself.

...Mike
__________________
There is a very fine line between "hobby" and "mental illness." Dave Barry

My flickr photostream has day-to-day stuff and I've given up most everywhere else through lack of time or perhaps interest.
  Reply With Quote

Old 08-25-2009   #6
Roger Hicks
Registered User
 
Roger Hicks is offline
Join Date: Apr 2005
Location: Aquitaine
Posts: 23,947
Dear Rem,

Yup, they're scanning as colour. Why wouldn't they? At their prices they're not a custom lab. Everything goes through the same scanner.

Kodak chromogenics usually wet print better than Ilford on colour paper, and are finer grained, but XP2 Super is sharper and (we find) easier to wet-print on B+W paper. We also prefer Ilford's tonality.

Cheers

R.
  Reply With Quote

Old 08-25-2009   #7
Leigh Youdale
Registered User
 
Leigh Youdale is offline
Join Date: Apr 2007
Location: Sydney, Australia
Posts: 1,629
I'm just in the process of starting to print digital scans from film negs too. One thing I've found in the past is that my local (Fuji) colour lab usually prints B&W with a slight blue cast. Something to do with the colour paper and the chemicals I think. I don't let them print any more but just get the scans on CD (I ask for TIFF not JPEG) which they don't like doing and charge extra but for my part I don't like the amount of compression they apply to the JPEG files.
Then I work them over in Photoshop Elements 6. Now, the TIFF files are quite large compared to the JPEGs, but both come as RGB scans. Previously I've immediately converted the file to Grayscale but I'm beginning to understand that this prevents some options I could use if I kept the RGB channels but desaturated them.
Can anyone elaborate on that?
__________________

Fuji X10
Leica M6
Bessa R4A
Rolleiflex (3): E3 Planar 2.8, WA & Tele
Nikkormat FTn (2)
  Reply With Quote

Old 08-25-2009   #8
Roger Hicks
Registered User
 
Roger Hicks is offline
Join Date: Apr 2005
Location: Aquitaine
Posts: 23,947
Quote:
Originally Posted by Leigh Youdale View Post
I'm just in the process of starting to print digital scans from film negs too. One thing I've found in the past is that my local (Fuji) colour lab usually prints B&W with a slight blue cast. Something to do with the colour paper and the chemicals I think.
They could equally well print with any other cast, or even (with enough effort) neutral. On my suggestion, one lab I used always went for warm, to the point of sepia.

Something that's worth knowing is that there are no neutral black (and hence grey) chromogenic dyes. These are something of a Holy Grail. Kodak apparently developed one once, but I don't think they've ever used it. Or maybe it didn't work as well as they'd hoped.

Cheers,

R.
  Reply With Quote

Old 08-25-2009   #9
remegius
Registered User
 
remegius's Avatar
 
remegius is offline
Join Date: Feb 2008
Location: Rohnert Park, CA
Posts: 293
Quote:
Originally Posted by Roger Hicks View Post

Yup, they're scanning as colour. Why wouldn't they? At their prices they're not a custom lab. Everything goes through the same scanner.
OK...I see what is going on here. I only have Costco develop and scan. No cuts, and no prints. And once I convert to grayscale, no problem. BTW, the scans I am getting from my local Costco are 3087x2048, and are very good. I made an 11x14 print last night on my 9180 and was quite pleased with the result.

Cheers...

Rem
__________________

Above all else this is the greatest treason, to do the right thing for the wrong reason.
  Reply With Quote

Old 08-25-2009   #10
Tango
-
 
Tango is offline
Join Date: Aug 2009
Posts: 3
Some say that scanning black and white negs into RGB colorspace will give greater tonality.
I suggest listening to Stephen Shaub's audio post at Figital revolution, HERE.
It's very interesting.
  Reply With Quote

Old 08-25-2009   #11
Benjamin Marks
Registered User
 
Benjamin Marks is offline
Join Date: Mar 2005
Location: Vermont
Posts: 2,665
I'm with Roger on this one and have found the same. You can convert your b&w RGB scans to greyscale if you want, but recently I have found that some applications (like the offset printing process offered at blurb.com) prefer an RGB file, even if the output is supposed to be monochrome. I have many scanned b&w chromogenic digital negs for which I have discarded the color information. For many of them I want it back and my only option is to re-scan. Moral: easier to keep as much information as you can in your "digital negative" -- you can always discard RGB color information in a working copy, but once you have deleted it that information is either gone or will be a pain to restore. With the astounding drop in the price of storage media over time, you are not likely to be punished for saving larger digital negative files now.

Ben Marks
__________________
Benjamin’s Gallery
  Reply With Quote

Old 08-25-2009   #12
oscroft
Registered User
 
oscroft's Avatar
 
oscroft is offline
Join Date: May 2006
Location: Liverpool (UK) & Bangkok (Thailand)
Age: 60
Posts: 2,347
Quote:
I could be wrong but I don't think it can be processed correctly using b/w chemicals.
It can be processed with B&W chemicals, but that would only produce the initial silver image.

To get the final chromogenic dye image (and bleach the original silver image), you need the full C-41 process.
__________________
Alan

My Flickr
  Reply With Quote

Old 08-25-2009   #13
remegius
Registered User
 
remegius's Avatar
 
remegius is offline
Join Date: Feb 2008
Location: Rohnert Park, CA
Posts: 293
Quote:
Originally Posted by Benjamin Marks View Post
I'm with Roger on this one and have found the same. You can convert your b&w RGB scans to greyscale if you want, but recently I have found that some applications (like the offset printing process offered at blurb.com) prefer an RGB file, even if the output is supposed to be monochrome. I have many scanned b&w chromogenic digital negs for which I have discarded the color information. For many of them I want it back and my only option is to re-scan. Moral: easier to keep as much information as you can in your "digital negative" -- you can always discard RGB color information in a working copy, but once you have deleted it that information is either gone or will be a pain to restore. With the astounding drop in the price of storage media over time, you are not likely to be punished for saving larger digital negative files now.

Ben Marks
I think that there is some confusion here. There is no color information with BW400CN. It's a black and white film. However, Costco processes as RGB, and this leads to files that, at least on my computer, have a color cast. Once I convert the files in question to grayscale all is well. Today I picked up some 120 BW400CN that I had developed at my local camera shop (Costco doesn't do 120) and, guess what, this stuff was developed correctly, which is to say it was developed as grayscale, not RGB, thus saving me the initial step of having to do a conversion.

Cheers...

Rem
__________________

Above all else this is the greatest treason, to do the right thing for the wrong reason.
  Reply With Quote

Old 08-25-2009   #14
kermaier
Registered User
 
kermaier's Avatar
 
kermaier is offline
Join Date: Mar 2007
Location: Northern New Jersey
Posts: 1,681
IIRC, Kodak BW400CN has an amber film base mask, which is intended for printing on color process machines. This, I believe, leads to color casts when scanning that need correction. On the other hand, Ilford XP2 Super has a clear film base, which makes it suitable for printing in a traditional black & white wet darkroom. This makes for a more neutral scan.

::Ari
__________________
M9-P, Fuji X100
  Reply With Quote

Old 09-20-2009   #15
ElectroWNED
Registered User
 
ElectroWNED is offline
Join Date: Jan 2007
Location: New York
Posts: 487
I shoot XP2 and have it developed at Walmart. May not produce super-high quality pictures, but they are good enough that nobody on the internet notices. But, I do have the same problem you do...

I always go into PhotoShop and auto level, auto contrast, then hit the "Black & White" effect to actually make them black and white. Otherwise, the XP2 processed from Walmart is purple-ish and grey, not black and white
  Reply With Quote

Old 09-20-2009   #16
Pablito
coco frío
 
Pablito's Avatar
 
Pablito is offline
Join Date: Jun 2006
Location: Salsipuedes
Posts: 3,481
Quote:
Originally Posted by ElectroWNED View Post
I always go into PhotoShop and auto level, auto contrast, then hit the "Black & White" effect to actually make them black and white.
"hitting the 'Black & White effect' " does not make them grayscale, they ares still RGB. You need to convert in Image/Mode if you want real grayscale.
  Reply With Quote

Old 09-20-2009   #17
mh2000
Registered User
 
mh2000's Avatar
 
mh2000 is offline
Join Date: Jun 2008
Posts: 1,145
you have to tell the operator to hit the b&w button. then all the data will be converted to b&w without a cast. yes, it will be saved as a RGB jpeg, but what do you care? in compression you don't even get much difference in file size.
  Reply With Quote

Old 09-20-2009   #18
hlockwood
Registered User
 
hlockwood is offline
Join Date: Jul 2007
Location: Boston metro area
Posts: 932
Quote:
Originally Posted by ElectroWNED View Post
I shoot XP2 and have it developed at Walmart. May not produce super-high quality pictures, but they are good enough that nobody on the internet notices. But, I do have the same problem you do...

I always go into PhotoShop and auto level, auto contrast, then hit the "Black & White" effect to actually make them black and white. Otherwise, the XP2 processed from Walmart is purple-ish and grey, not black and white
I've been using XP2 exclusively for a while now. When I get the uncut negs (+CD of Jpegs) from the local camera shop, I scan (Nikon 4000ED), in RGB mode, the frames I want to print and then open them in PS/CS3. I then convert the RGB file to Lab, discard the a & b channels and change the mode to Grayscale. Seems to work quite well.

Harry
__________________
Harry Lockwood

Leica M7/0.85, Hexar RF, M9-P and a bunch of lenses.
  Reply With Quote

Old 09-20-2009   #19
peterm1
Registered User
 
peterm1's Avatar
 
peterm1 is offline
Join Date: May 2006
Posts: 5,501
Most color labs do not know how to process this stuff - or to put it more precisely cannot be stuffed doing it right. As I understand it, every film has to have the color bias set in the processing machine to account for the films own bias towards producing a color cast. And they are all different. And while its nominally a black and white film its being processed like a color film. So if the machine's color channels are not set correctly bingo you get a color cast. Sepia is common but when they really screw up you can even get pink or blue! If you are printing to a print you should ask if they can print on black and white stock - this avoids the problem. But few labs will do this for you. If not and you are processing to digital as it sounds like then you have to reconcile to doing what you have done. For me, I now prefer to shoot color then post process to black and white. Saves the hassle.
  Reply With Quote

Old 09-20-2009   #20
ElectroWNED
Registered User
 
ElectroWNED is offline
Join Date: Jan 2007
Location: New York
Posts: 487
Quote:
Originally Posted by Pablito View Post
"hitting the 'Black & White effect' " does not make them grayscale, they ares still RGB. You need to convert in Image/Mode if you want real grayscale.
doesn't really matter much for my purposes. I'm not printing images that I have developed/scanned at Walmart. Plus, they look exactly the same.
  Reply With Quote

Old 09-20-2009   #21
amateriat
We're all light!
 
amateriat's Avatar
 
amateriat is offline
Join Date: Nov 2004
Location: Brooklyn, NY
Age: 63
Posts: 4,282
Here's how it goes:

- Kodak BW400CN, like its predecessor, T400CN, has an orange cast, similar to Kodak's (and Fuji's, among others') C41-process color-negative film. Any color-neg printing/scanning process takes that orange cast into account while working its magic in making lovely 4x6" prints. If i recall, there IS a "channel" program in most one-hour printing machines that can handle chromogenic films like T400CN and BW400CN, but not chromogenics such as Ilford XP2 Super, OR Kodak's short-lived chromo (I think it was called BW400) which do NOT have the orange mask, making them (somewhat) easier to work with in the wet darkroom.

Y'all caught?

Anyway...I alternate between XP2 and BW400CN (shot a bit of the former in PA this weekend for a rare, out-of-New-York experience), depending on availability and mood, more or less in that order. XP2 is better for wet-darkroom printing, while BW400CN really wants to be scanned. Of course, XP2 scans gorgeously. But XP2, at least here in Nueva York, runs at least a buck more per-roll than BW400CN. And, hell, I'm pumping more money into my state's economy by buying from Old Yeller.

What's a film shooter to do these days?!


- Barrett
__________________

"Print 'em both, kid." -
Frank "Cancie" Cancellare, to a UPI courier, after tossing a 20-exposure roll of film to him.

Here, a Gallery.
  Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 05:24.


vBulletin skin developed by: eXtremepixels
Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

All content on this site is Copyright Protected and owned by its respective owner. You may link to content on this site but you may not reproduce any of it in whole or part without written consent from its owner.