Film Latitude what is it?

Knowing the film latitude in BW is one exciting concept in mastering this format. When we shoot in BW, we are concern mainly with three things: shadows, highlights, and various shade of grays. If we can reproduce them correctly, we have ourselves a good photograph.

What is film latitude? It is basically a property of specific film to capture various shades from pure black to pure white. Another term is contrast. Most films have 5 F-stops latitude. If important subjects fall within 5 stops, this means we are capturing enough details to make a good negative.

This gray card is calibrated in ½ F stops for a total of 5 full stops.

http://i217.photobucket.com/albums/cc75/nikonf2/Graycard.jpg

By knowing this concept allows us to make exposure decision before taking that shot. Since we are not doing digital, we cannot preview our mistake! By metering the important subjects we can determine whether they will fall within the film latitude and be guaranteed details in the negative. If the important scenes are beyond the film latitude, we will have to compromise on which part of the scene we want to lose details. One example is the classic beach shot. The contrast here will surely beyond five stops. We can opt to give the highlights priority, and then add lights, reflector, or fill in flash to bring the shadow detail to within the 5 stops range for this particular scene.

I did not cover everything. So go ahead fire up your questions for this thread.

Dan T

Good thread sir, i only have an ambient light meter now (sekonic L358). Lets say, i'll take a portrait of someone...the usual method in color is to take a reading close to the subject face..should the same discipline apply with BW? or should i bracket for the shadows(open 1/2-1 stop) (expose for the shadows)?

i saw a dedicated 3 degree spot meter for sale..is this enough?

wow!... i bet most of the members will benefit from this thread... thank you Delfin! another thread worth reading.:)

Good thread sir, i only have an ambient light meter now (sekonic L358). Lets say, i'll take a portrait of someone...the usual method in color is to take a reading close to the subject face..should the same discipline apply with BW? or should i bracket for the shadows(open 1/2-1 stop) (expose for the shadows)?

i saw a dedicated 3 degree spot meter for sale..is this enough?

Quick question - are you taking an incident or reflectance reading of the subject? Just to clarfiy; incident metering measure the light FALLING into the subject while reflectance measure light REFLECTED from the subject. I have another thread about how meter actually read objects.

If you are using it as an incident meter, your method is correct of taking close up reading. But for color film, the latitude is only 1 f-stop over/under. For slides even less. I usually follow the meter reading. No need to compensate for color film.

If you want to take control of your exposure and do advance photography, spotmeter is way to go. I have a 1 degree spot meter I use for my LF. I have other thread coming on spotmeter, zone system, finding your personal ISO base on your equipment in the making.

Dan T

@ Delfin,

Isn't the 5 stop latitude due to the limitation of photographic printing paper (offset printing having a stop less)?

How does this relate the zone system given that each zone is a one step giving 10 stops from pure black (zone 0) to pure white (zone 10)?

Won't 5 stops be closer to the narrow latitude of slide film (4-5 stops)?


@ Ari,

As Delfin said, a spotmeter would give you more control. A 1º spot meter more so and critical for zone work.

@ Delfin,

Isn't the 5 stop latitude due to the limitation of photographic printing paper (offset printing having a stop less)?

How does this relate the zone system given that each zone is a one step giving 10 stops from pure black (zone 0) to pure white (zone 10)?

Won't 5 stops be closer to the narrow latitude of slide film (4-5 stops)?


Let me answer the easy one first. Color Slide will usually give you the most 1 f-stop over/under.

The five f-stop film latitude is not really a static rule in terms of getting the "correct" photograph. You want to keep within that f-stop range if you want good details in your final photo. Obviously there will be less detail if you are aiming for high key photos.

Printing paper actually supplement the negative in terms of what the final result when printing. Most darkroom printers do not think in terms of latitude but in contrast grade. Paper comes in grades from 00 to 4. Low contrast paper will have a grade of 00-1 and for a high contrast paper of 4. Number 2 is used for "normal" contrast. For a low contrast negative you would want to bring the contrast to "normal" range. A paper grade 3-4 will compensate for lack of contrast.

The illustration I showed is just a visual guide on how negative will react to different shades of grey when taken at a specific shutter/f-top combination. It was not intended discuss Zone System. The test negative is actually Stouffer step wedge http://www.stouffer.net/TransPage.htm. I was going to start another thread on Zone System later on.

Delfin, yes sir, incident reading...i have some questions regarding the Zone system, will look forward on the thread about it. Checking the histogram is no fun :(
When are we having that 'talk' about Large format and analog photography sir?

@Edwin, 1 degree would be nice...i almost traded my L358 for a L558 but didnt push through..sayang :( always wanted one knowing i would need it someday...but budget constraints led me to just get the L358...

Ari,

Incident meter is a favorite system used by photojournalists. I used my old Weston Master V in incident mode. Due to the unpredictability of the subjects in photojournalism, incident metering is the way to go. Incident meters take an average luminance of the scene. It disregards any undue reflectance from subjects causing exposure errors. The incident meter is also good for measuring lightning ratio for portraiture.

Here is a website on Zone System, http://photography.cicada.com/zs/ The author even have a zone system emulator where you can practie the system. Go look and ask me subjects that are not clear to you.

What topics you want on LF? We can continue my old LF thread once I know want you are interested in.

Dan T

OT:

How much is a new Sekonic L358 now? A friend lent me his Sekonic light meter after I purchased a TLR. I'm having a grand time using it so I want to purchase one, if it suits the budget. :Grin: TIA

B&H Photo sells L358 for $259.00 in the US. You can use that amount as a base price when you are shopping.

BTW, I have a L398. This one does not need battery. Runs on selenium cell. Cost $179.00.

http://i217.photobucket.com/albums/cc75/nikonf2/435535.jpg

The five f-stop film latitude is not really a static rule in terms of getting the "correct" photograph. You want to keep within that f-stop range if you want good details in your final photo. Obviously there will be less detail if you are aiming for high key photos.

But isn't a five stop range too short for BW negative film? Published data and common practice (based on my practice and sources including reading film curves from manufacturers technical sheets) average exposure range as follows: 10 stops BW Neg, 7 stops Color Negs, 4-5 stops Color Slide. For those wanting to compute themselves, check for the manufacturers data and measure the linear portion of the curve. A .30 change in Log Exposure is equal to a doubling of exposure i.e a full stop. (c.f. pp. 263-264, Ansel Adam's The Negative).

An interesting trivia: according to test by Kodak engineers, TMAX, in special scientific applications can have a range of 22 stops. Google Gordon Brown (not the new UK PM) with TMAX Kodak to read more.

Printing paper actually supplement the negative in terms of what the final result when printing. Most darkroom printers do not think in terms of latitude but in contrast grade. Paper comes in grades from 00 to 4. Low contrast paper will have a grade of 00-1 and for a high contrast paper of 4. Number 2 is used for "normal" contrast. For a low contrast negative you would want to bring the contrast to "normal" range. A paper grade 3-4 will compensate for lack of contrast.

The illustration I showed is just a visual guide on how negative will react to different shades of grey when taken at a specific shutter/f-top combination. It was not intended discuss Zone System. The test negative is actually Stouffer step wedge http://www.stouffer.net/TransPage.htm. I was going to start another thread on Zone System later on.


Certainly paper is commonly referred to in grades but as photographic materials go the range can be measured in stops (data which can also be deduced from Log Exposure curves). For example Grade 0 paper has an average range of 5 stops, Grade 3 at around 3 stops, Grade 5 around 1.5 with max print densities at around 2. Hence my confusion as to why you used the 10 step Souffer wedge as an illustration which has a max density of 1.4 (close to the Dmax of photographic paper). Won't the 21 Step or even better the 31 or 41 Stouffer step wedge be a better illustration as they cover the max densities of film to around 3.05 (Dmax of 21 and 31 step from Stouffer).

And lastly, I'm confused by your definition ("It is basically a property of specific film to capture various shades from pure black to pure white") as it sounds more like film exposure range rather than film latitude. Doesn't one have to consider SBR (Subject Brightness Range) with the film exposure range to determine film latitude.

For example if my SBR is around 5 stops and my film has an exposure range of 7 stops, I have a film exposure latitude of around 2 stops, i.e an exposure error of 2 stops (although in most cases for neg film the two stops extra would be more in favor of over exposure rather than under exposure), thus we can say that we have enough latitude to play with. The same scene with the same SBR when shot with film having a 5 stop exposure range would have no latitude at all, thus hardly no room for exposure errors.

Given that "normal scenes" have an SBR of around 5, films with a higher film exposure range have high latitude in relation to this SBR as base. Film with an exposure range of equal or lower than this base would then have narrow latitude.


Pardon me if I seem to be hijacking the post you started. It actually made me bring out the books and read them again. I'm planning to buy a 4x5" Stouffer calibrated 31 step wedge to do some tests which I'll share here as soon as I have time although Paul Butzi has done some testing (http://www.butzi.net/articles/zoneVC.htm) already.

BTW, I've used the following books for reference (of course along with the usual online sources that is LF Info Forum (http://www.largeformatphotography.info/forum/), APUG (http://www.apug.org/), photo.net (http://photo.net/), grossformatfotografie.de (http://www.grossformatfotografie.de/)): Ansel Adam's The Negative, Steve Simmons' Using the View Camera, Urs Tillmans'/Sinar Editions' Creative Large Format.

Cheers,

Edwin

@ Delfin, not necessarily about LF sir, i'm just at awe when people talk about these stuff...want to absorb as much as i can from you guys...especially developing my own BW. I found this site http://chromogenic.net/verba/070822. It seems so easy reading it...sourcing those stuff is another.
Bookmarked the site already..thanks for sharing sir...
I also want to peep through your 4x5's ground glass if i may...:D

@jed, i got my L358 for $240...but if you can afford the L558 with built in spot meter..go get it..i wish i did.

Edwin,

Good response. Thanks.

For the record, yes films will reproduce more than 10 f-stops range.

In Zone System, the criteria are to produce good shadow and highlight details that the photographer deem important in the photograph. The common practice is to place shadow with good detail in Zone III and highlight detail in Zone VII.

Here is my take on the 5 f-stops latitude I was taking about.

If you use the classic Zone System as a guide, and I clarify this as a GUIDE, it has 10 steps. Zone I (black+fog) to Zone X (pure white). So for a given scene, you can have a spread of more than 10 stops from black (no detail) to white (no detail). Now in using the zone system, and to stay within those 5 stops, Zone III will give you good TEXTURAL details in the shadow area and Zone VII will do the same in the highlight area. Anything below or above those Zones will have less or no textural details. Film will reproduce those other area according to Zone System terminology “place and fall”.

I do not understand what you mean by Subject Brightness Range. Here is my “workflow” if you will; based on the Zone System. I take a meter reading of an important shadow area and will place that on Zone III. Then I will meter the brightest part of the scene that I want detailed and place it on Zone VII. If that bright part of the scene is within that 5 f-stop, I will have a normal negative, based of the Zone System criteria.

What if the important highlight area is in Zone IX? A two f-stops exposure than Zone VII. I now have a 7 f-stops range. Is this what you mean by SBR? If I decide to include that highlight, I will be making a “place and fall” decision. I will now have to do a N-2 development after I take the photograph. This is to bring the overexposed Zone IX to Zone VII by under developing the negative. Remember the classic rule in BW developing? “Expose for shadow and develop for highlights”. I did not change my exposure so my shadow area is still properly exposed.

Come printing time, if Grade 2 is not enough to bring the highlights to acceptable level, I might use Grade 1 or 0. Or use VC paper and filters. Remember I am talking about the basic Zone System methodology.

On Page 54 of the Negative there is an illustration of the different Zones as placed in the photograph. You can see the fence (Zone III) has details compared to the church steeple (Zone I).

I think you should start an advance thread about exposure and other film BW topics.

Dan T

Ari,

I went to the site you are talking about. There good website to read about. But our hobby is hands on. I know materials are hard to come by nowadays. Basil was talking about a coop kind of group that can buy materials in bulk. Hopefully get discount too from suppliers.

What topic do you want on film development? Do you have any darkroom equipment?

I am waiting for September to re-start my BW darkroom again. It will be cooler then. I will post photos of my LF gear. Did you see Edwin's gear on LF thread?

Dan T

this is too much techincal stuff for me.. :( just starting B&W. do i really need a light meter? i mean is the SLRs TTL meter not enough?
Dan, am really confused on the zones your mentioned. any link i can read that is for dummies? say something like how stuff works.. :D

Delfin,

Easiest i heard was D76..so, i would probably start from there as i go on. I dont have any equipment yet..i want to see an actual development first before diving into this...Raena abella, also a member here is putting up her own darkroom in her house in antipolo and its about ready by sept...really good news for film.

On my way to Isa Lorenzo's Silverlens studio, she is conducting an Artist Talk this afternoon..i like attending in these kinds of stuff to keep me inspired. just like watching this thread :)

Edwins LF gear....i could only dream bout those stuff. :)

Dan to start with thanks by starting the thread. It helps spread knowledge and keep it alive.

By measuring the scene, you're actually measuring SBR i.e. difference between the darks and highlights that are important in the scene. And knowing this and the capabilities of your film as you already do, you already visualize how the photograph is going to look like on film and paper. If your SBR exceeds that of film then you'd have to go to N- development (as you explained in your previous post) or if it is much shorter the possibility to do N+ development to match your workflow. SBR is just to encapsulate what you and zone practitioners have already been doing since starting with this system. Here's an article (http://www.largeformatphotography.info/articles/conrad-meter-cal.pdf) by Joseph Conrad on the LF Info forum. I have to admit the first time I read it it went over my head and this thread "forced" to read it again. :Grin:


I think you should start an advance thread about exposure and other film BW topics.
Dan T

I think I'm in no position to start an advance advanced thread. There are other more knowledgeable people out there than me. I'll join in other threads of course if I have something to share.


To Paeng, Ari and the rest who are interested ,

The late Barry Thronton's site (http://www.barrythornton.com/) is still being maintained by a student as a service to the photographic community. Articles of interest in the Technical Guide section would be on Zone System Basics and the No Zone/Unzone Sytem (where he goes at length in how to control exposure and learn from your contact proofs for 35mm and MF users).

Ari,

It would be great if you have access to a darkroom. But if not all is not lost, you just have to fit your process to the workflow of your lab. So knowing things like what kind of developer they use, what kind & grade of paper do they print your proofs and enlargments on, what kind of enlarger do they use etc, then you'd at least know the variables your working on.

BTW, Ansels Adams' The Negative is quite an old book. If you have access to a good university library, they would probably have it as it's been one of the standard books for photography education.

Just a thought, my Sekonic 758-DR was made in the Philippines. Try contacting a local Sekonic representative for local pricing. It might be cheaper back home since tariffs and other duties would be virtually non-existent.

Paeng,

It actually sounds a lot more more technical that it actually is in practice. By all means use your TTL metering, if it has spot capabilities then you have an additional tool for measurement. When I didn't have a handheld meter, I used an old minolta body with the matching focal length as a meter for my non-metered cameras. I think what's important is that you know what your meter is telling you so you can determine if it's over, under of spot on. Go out and shoot. With experience you'd soon be able to guess approximate exposure even before actually metering the scene.

Kudos to Raena Abella for opening her darkroom to others.

Cheers,

Edwin.

P.S. Dan, I think it's about time you start a Zone thread. :)

P.P.S Regarding my gear, I'm lucky to be on continental europe where it's still easy to find good used analog gear for cheap and I mean the type of cheap where you could actually bargain since they just want to be rid of the stuff and even throw freebies since they're so happy I took their junk. Although not cheap enough (that is to say completely free) so I had to forego replacing my powerbook for a macbook pro and not going on summer holidays (thank god I have enough scenic areas to shoot a short train ride away from my doorstep). I'm not a gear head per se. I'd actually buy more film than equipment. :)

edwin,

i have a k1000. its meter is just a pin that fluctuates if its over or under.. thats the only metering i have.. btw, any of you guys know where i can find developing reels wherein i dont need a darkroom? starting to love B&Ws all over again! :)

this is too much techincal stuff for me.. :( just starting B&W. do i really need a light meter? i mean is the SLRs TTL meter not enough?
Dan, am really confused on the zones your mentioned. any link i can read that is for dummies? say something like how stuff works.. :D

Paeng,

You do not need a seperate exposure. Your slr meter would do. Remember our cameras and materials are just tools. We are the master of our tools. :)

Here is a link about Zone System. The author has an emulator that you can practice online.

http://photography.cicada.com/zs/

Zone System is basically a visualization exercise. By using exposure compensation, developing film ,and finally by printing; you produce a print that reflects what you see during the time you made the photograph.

I am going to start another thread that will incorporate all of this discipline. I promise it will be simple. We have a popular TV ad here and it goes like this: "...so simple a caveman can do it". :Grin:

Dan T

Edwin,

I went to read Josef Conrad article. There are various re-incarnation of the Zone System. Fred Picker was the first one to simplify the the system. Minor White wrote a book too. The most technical one is Beyond The Zone System by Phil Davis. Davis made the system as automatic as you can get it. He has a program that will do all the calculation on Palm PDAs.

The system is just another tool for us to use. What nice about it after visualizing the scene and decided what do with the technical aspects of it; come printing time, hopefully there will less burning and dodging to do since those "stuff" had been taken into consideration before pressing the shutter.

Since you in Europe, you might want to check the Analyser Pro from http://www.rhdesigns.co.uk/darkroom/html/exposure_meters.html Now this is mother of all printing meters. You may want to read about F-STOP printing too.

Dan T

Delfin,

Easiest i heard was D76..so, i would probably start from there as i go on. I dont have any equipment yet..i want to see an actual development first before diving into this...Raena abella, also a member here is putting up her own darkroom in her house in antipolo and its about ready by sept...really good news for film.


That will be the same time I am planning to continue my BW work after venturing into digital realm. I will post my work as I go along.

D-76 is pretty much de facto developer for most photographers. I use it 1:1. This means that after mixing the the D-76, you will mix the stock developer with same amount of water. So if your developing tanks needs 1 liter, you will mix 500ml of stock D-76 with 500ml of water. The bad thing- 1:1 dilution is single shot. You cannot use the chemical again. Bummer.

Dan T

Paeng,

Delfin is right. We have to master the tools we use. In your case know what your camera meter is telling you. So that means for your K1000 (center weighted averaging meter), you know that it will give you a proper exposure for "normal scenes", as averaging meters go, it will give you the wrong overexpose scenes with predominantly black tones (the famous black cat example) while underexposing scenes with predominantly white tones (beach, snow scenes). Knowing this and with experience, you'd know how to adjust your exposure from what your meter reads.

As to daylight tank with reels, I wouldn't know where to find reels and tanks in the Philippines. You could try contacting Raena here in the forums as she is in the process of setting up her darkroom. She might lead you to other sources closer to home. Jobo tanks seems to be default and are common on ebay. Kaiser (http://www.kaiser-fototechnik.de/pdf/KatalogE/13_Lab.pdf) still makes universal developing tanks for hand inversion. They have representation in HK, Malaysia and Thailand so you might try contacting them.

Delfin,
Yes read through BTZS a while back and in fact I considered running it on an old palm i have lying around. Fred Picker is recommended by a lot zone users too.

The RH Analyser Pro is quite an impressive machine, I checked it out when I acquired my enlarger but the price is quite prohibitive. If I do find one during the International Photo Antiques and Camera Fair (http://www.photoflohmarkt.ch/welcome_en.html) (it's a half-hour by train from where I live), I'd probably buy if the price is right. :) Ditto the stop-system, I'm planning to do a summer course in Paris with Speos (http://www.stop-system.com/) depending on mood and budget, a you said they are all tools and I'm running along nicely guided by the trio of Ansel Adam's books. There's also platinum printing that I want to start (I actually have most of what I need including chemicals). Too many choices, too little time and I'd rather be out shooting if not for the wacko summer weather we've had this year.

Cheers,

Edwin