Film speed test Ilford FP4 no densitometer

Film speed test Ilford FP4

Film speed test - use just 2 sheets of film - no densitometers

Film speed test Ilford FP4Film speed test using Ilford FP4 to establish your personal film exposure index and normal development time - no need for densitometers with this visual check using a graphic arts step-wedge tablet.

What I am going to explain below is a quick overview for one method of film speed development test and how to obtain your normal development time. It is particularly handy for 4x5 users as it minimises the amount of film used down to potentially two sheets to give you the necessary information.

A more in depth reference to this film speed test and where to obtain graphic arts step tablets are listed at the bottom of this page.

Step 1 Load step tablet and unexposed 4x5 sheet into a film holder

This film speed test uses a Stouffer step wedge as your calibration tool. Modify your step tablet by placing an opaque paper dot sticker above step 21 on the tablet. This will prevent any light being received by the film under the dot, giving you a clear film base reference point later.

The 21 step tablet or step wedge is a calibration device traditionally used in graphic arts applications. It has been carefully processed under laboratory conditions to give 21 steps of grey in 0.5 stop densities. Using a step tablet is one way to avoid the need for densitometers.

In a darkroom or film changing bag load an unexposed sheet of film overlayed with the Stouffer step tablet. The two are sandwiched together and carefully pushed into place within the sheet film holder. Due to the combined thickness of two sheets this can be a little difficult but can be achieved with patience and care. Treat the test tablet with the same care as film.

Step 2 Expose the film with step tablet with a Zone 10 exposure

Film speed test Zone 10 film exposure test
Exposing film with step tablet

A Zone 10 exposure is 5 stops more exposure than what your meter is indicating. Observe the following points:

  • Use a white card as your exposure subject and fill the viewfinder completely. If you use a darker object the exposure time required will be longer, hence use white.
  • Choose a normal focal length lens - wide lenses suffer from light fall off at the frame edges and can affect the test
  • Have your lens focused at infinity. The test object will not be in focus and focus is not desirable for this test.
  • Choose a day with consistent light, cloudless, south facing is best if in the southern hemisphere.

Step 3 Develop your test film in the developer of your choice

My current developer is Ilford LC-29. You should choose for your test the developer that you prefer or want to use with your film. Prepare it as you would normally would and be consistent with your film processing procedure so you can repeat the results.

For my processing set up, Ilford HP5 takes about 11 minutes to develop normally. Looking at the Iford tables for FP4 suggests that it develops in slightly less time that HP5. So I cut my time from 11minutes down to 10 minutes. Why? 10 is an easy number to work with. If I need to reduce or increase my development times further I will usually adjust by about 10% increments (1 minute) or 15% (90 seconds) or 20% (2 minutes).

Film speed test stouffer negative jobo film reel FP4
My developed film test at 10 minutes

Step 4 Analyse your results to get your personal film speed index

Film speed test stouffer negative

 

The first piece of information in a film speed test is at what ISO speed should I be exposing brand X film with my camera gear and development procedure.

This is where placing the opaque sticky dot near the 21st step is so helpful, circled in red. It gives you a clear film base reference where no exposure has been received. Step 21 on the wedge is also Zone 0. If it is the same density as the red circled clear film base then the film is not overexposed. If step 21 is equal to the circled area and there is consistent tonal separation between steps 20 to 11, then your exposure index is within the ball park. I exposed this test film at 64ISO and I am pretty happy with the tonal placement.

If steps 21, 20, 19 had been clear with no tonal separation between them, then I know the film was underexposed. I would need to reduce my ISO number by about half a stop and try the test again.

Conversely, if steps 21, 20 and 19 had definite grey tones I would need to decrease my exposure by increasing my ISO rating for the film.

 

Step 5 Proper proof time

From the previous step I am confident that an ISO of 64 is close enough for my camera and developer combination. Now I need to find out what is the normal development time.

proper proof time

A second sheet of FP4 which remained unexposed was also developed at the same time as the step wedge test for 10 minutes.

For all contact printing I have a standard enlarger head height I use in combination with one lens, f stop and neg carrier. My enlarger filtration is set for grade 2 normal contrast paper. I focus the light onto my enlarger base and then make tests strips from the contact print of the developed but unexposed film.

What I am looking for is the first almost black tone which shows very little discernible tonal difference to the next strip after it. This is in the region of the minimum print exposure required to print through the unexposed film to yield a black print value.

In my case above, I could see clear differences between the dark greys at exposures of 8.6 and 10.4 seconds. At 12.4 seconds I could see no appreciable change in blacks between 12.4 and 15.0 seconds. So I choose the 12.4 seconds as the minimum time to achieve close to maximum black.

A note of caution, this is a visual test and it is easy to be overly enthusiastic about achieving maximum black thereby overexposing when establishing your minimum time for close to maximum black.

Here we are working at an extreme end of the paper sensitivity where small changes in exposure can give large changes in density, so take care not to overdo it.

Remember that you want the exposure time just before there is no real appreciable difference in the black with next exposure time which follows.

Step 6 Establishing normal development - printing the step wedge.

This is the final stage, establishing what is a normal development time for your film, camera and developer combination. We need to make a contact print of the actual Zone 10 film exposed with the image of test tablet. Using the exposure determined above for the minimum time for maximum black (in my case 12.4 seconds) I  contact print the negative onto the photographic paper. The result is seen below.

contact print step wedge

In the image above I have shown in red letters the various print value zones and their respective step tablet numbers. Remember each step is 0.5 of a stop. Step 1 on the tablet is equivalent to a Zone 10 print value, Step 2 is half a stop lower at Zone 9.5 and Step 3 is Zone 9.0 respectively.

I like to have a good separation of tones from Zone 2 print value (Step 17) through to about Zone 8 print value (Step 5). After Step 5 - Zone print values 8.5 to 10, the scale remains paper base white. This is a normal contrast range. If the light grey scale ended earlier at say Step 7, this would indicate the film has been developed with higher contrast than normal of about one stop. This is referred to N+1 development. If the grey tones extended all the way down to Step 3, or Zone 9 print value, then this would indicate the film contrast is softer than normal. This is represented as N-1 development.

In this case above 10 minutes development has produced results which show normal negative contrast.

Film speed test Ilford FP4 in LC-29 developer conclusion

Using just 2 sheets of Ilford FP4 film I was able to determine that my personal exposure index is 64 ISO. Normal development is achieved (for me) at 10 minutes using my usual dilution and agitation methods consistent with my film processing procedures.

I have only used my results here as an example of the process. Your results may vary significantly and that's to be expected.

Having conducted my film speed test for my personal exposure index and normal development I can now go about photographing with my new stock of Ilford FP4. This gives me a genuine basis to compare results of my images with other films I have used and to observe characteristics particular to this film and developer combination.

Conclusion:  Film speed tests are necessary to understand how to best manipulate your creative materials - your photographic film and paper.

References Calibration and Transmission Step Wedges

Film Speed Test References.

Paul Wainwright has written a nice little pdf which you can download which goes into greater detail the technical details behind this visual test. Go to this page, scroll  to the bottom third of the page “Use Your Eyes, Zone System Testing Without a Densitometer” and download the pdf off the link.

Visit Stouffer Graphic Arts for details regarding transmission step wedges and photographic scales, the tools I rely on to avoid the need for using laboratory equipment like densitometers, often referred to in the Zone System film exposure and development method. Keep your references clean, handle with care (like negatives) and store carefully, these will last you for years and well worth having.

Film speed test Ilford FP4 4x5 sheet film

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Film Photography Workshops Perth

photography workshops Perth

Perth workshops are for those who wish to learn about film based photography, using black and white film, chemistry and paper. We use large format 4×5 cameras down to medium format 6×6 and 35mm. You will be photographing on day 1 and developing and printing your work on day 2, hence the weekend time slot. For 35mm, medium format or 4x5. Bring your own camera or use one of ours, let me know your preference.  Film, paper and darkroom chemistry include. Max 2 participants per workshop, so get in early. If you wish to be advised of future workshop dates please email me.

Next workshop April 29-30 2017

If you are looking for suppliers of film, paper, chemistry, instructional books and helpful web sites then please visit my Suppliers and Resources page.

 

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Large Format Film Photography Workshops

Day 1 -View Camera Introduction

Kent St Weir, Wilson, on the Canning River

If you have ever been curious about the advantages of using a large format camera in your photography and what’s involved, or if you are just considering large format photography, then this workshop is for you. This introductory large format 4x5 workshop provides hands on experience and techniques, with applications for both portrait and landscape work.

Large Format Film Photography Workshops are conducted outdoors along the wooded banks of the Canning River Reserve, so you can see and experience using a 4x5 field camera on location. Through discussions and field demonstrations, I will guide you through the process of setting up and using a large format camera. You will then put this newly gained knowledge into practise by making your own 4x5 negatives around the river reserve.

The Canning River Reserve will provide ample subject matter and an ideal learning environment for you to gain experience in using a 4x5 field camera within a small group setting. Even if you don't own a 4x5 camera you will be provided with one to use, if you do have one then it bring it along. To maximise the experience, workshop numbers are limited to a maximum of 2 people. Facilities at Kent St Weir include the brand new Canning River Cafe or bring a sandwich.

film photography Point Walter Workshop

Day 2 - Darkroom Introduction to Film Processing & Printing

For participants who have just completed Day 1 View Camera Introduction, this provides a logical continuum to the large format processing and printing stages.

You will learn how to develop a black and white film, proper storage and care of negatives, archiving and the importance of making proper contact proof prints.

You will also have the opportunity to enlarge one of your black and white negatives and be guided through the process of making your first silver gelatin print. This workshop will be held in my darkroom and participant numbers are limited to a maximum of 2 people.

Workshop fee includes photographic paper, film processing and light refreshments. Bring your lunch. Weekend workshop fee (2 days) $525.

If you need more information please contact me.


 

 

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Processing 120 film with excessive curl

Processing 120 film with excessive curl in the film base

When you have just 5 or 6cm of film unrolled from the backing, pinch the very top centre leading edge of the film with finger and thumb of one hand and with the other holding the film reel and film roll, pull the leading edge of film under the entrance lips into the very first reel track. (Do not cut the corners of the leading film edge as this will make loading in this reel more difficult with a curling film).Processing 120 film with excessive curling can cause the film to jam or be damaged when loading into spiral reels for tank development. The following is a description of how I load 120 film with excessive curl into a daylight film tank for processing. Obviously all the steps shown must be completed in total darkness, ie in a darkroom or using a changing bag. I suggest you try this on a practice film before you try loading an important film.

I have been processing 120 films for several decades. In that time I have used stainless steel reels, Paterson reels and my current favourites, the Jobo duo reels shown here. These “newer” Jobo reels are made of white plastic rather than the earlier clear plastic reels. Unlike Paterson, Jobo reels do not have any ball bearings at the film loading mouth to engage the film edges. Unlike other reels, Jobo have two indented reel edges, one on opposite sides of the reel, where my finger is pointing. This is important as it allows the films edge to be contacted by your fingers within that small range of indent.

In a darkroom or change bag collect all the items necessary to start film loading. You will need daylight film tank and top, the white plastic film reel with its black central column and of course the roll of film.

Processing 120 film with excessive curl in the film base

In total darkness, tear the thin paper tab securing the exposed roll and begin to unroll the backing paper away from the film spool.

In total darkness, tear the thin paper tab securing the exposed roll and begin to unroll the backing paper from the film spool.

After about 10 to 15cm of backing paper is unrolled, the loose end of film will begin to curl into a small tight roll. The film is thicker than the paper backing and is firmer, so you will feel the difference between the two. Unless touching the very first of last 2cm of film, always handle the film at its edges.

After about 10 to 15cm of backing paper is unrolled, the loose end of film will begin to curl into a small roll. The film is thicker than the paper backing and is firmer, so you will feel the difference between the two. Unless touching the very first of last 2cm of film, always handle the film at its edges. (Yes what you see below is the pink emulsion of real, undeveloped film)

Notice how the film below is already curling in on itself to form a tight shiny roll. This action can make 120 and thinner 220 films particularly troublesome to load at times without scratching or jamming in the reels. The degree of curl will vary from film to film, brand to brand,  and manufacturers may change the polymer base without notice.

Notice how the film below is already curling in on itself to form a tight shiny roll. This action can make 120 and thinner 220 films particularly troublesome to load at times without scratching. The degree of curl will vary from film to film, brand to brand, and manufacturers may change the polymer base without notice.

When you have just 5 or 6cm of film unrolled from the backing, pinch the very top centre leading edge of the film with the finger and thumb of one hand and with the other holding the film reel and film roll,  pull the leading edge of film under the entrance lips into the very first reel track. (I do not recommend cutting the corners of the leading film edge as this will make loading in this reel more difficult with a curling film).

When you have just 5 or 6cm of film unrolled from the backing, pinch the very top centre leading edge of the film with finger and thumb of one hand and with the other holding the film reel and film roll, pull the leading edge of film under the entrance lips into the very first reel track. (Do not cut the corners of the leading film edge as this will make loading in this reel more difficult with a curling film).

Again using finger and thumb to grab the leading centre edge of film and pull the film into the reel past the indents, whilst holding the main film body and backing in place with the other hand.


Continue pulling the film around as far as you can. You will have to unroll some of the backing paper from time to time to free up the film so it will enter the reel freely.  You can let go of the main film roll once you have a good 10 to 15cm of film in the reel  as this should be sufficient to hold it.

Continue pulling the film around as far as you can. You will have to unroll some of the backing paper from time to time to free up the film so it will enter the reel freely. You can let go of the main film roll once you have a good 10 to 15cm of film in the reel as this should be sufficient to hold it.
Paterson reel users will be familiar with the backwards and forwards ratcheting movement of the reel halves to load film. A similar affect on the Jobo reels can be achieved using index fingers on each side of the reel at the indent points, as you alternatively advance and then hold the film.

Paterson reel users will be familiar with the backwards and forwards ratcheting movement reel halves to load film. A similar affect can be achieved using index fingers on each side of the Jobo reel at the indent points to alternatively advance and then hold the film.

I do not recommend this method with excessively curly 120 film as it is likely to pop the film edge out of the film guide channel, causing the film to jam.

I do not recommend this method with excessively curly 120 film as it is likely top pop the film edge out of the correct chanel in the spiral, causing the film to jam.

Instead, hold the reel perfectly still. With a finger and thumb placed at opposite sides of the film indent, push/feed  the film with light pressure in the circular direction of the film guide channels. You can only push/feed  the film the circular length of the indent at any one time.

With a finger and thumb placed at opposite sides of the film indent, push the film with light pressure in the circular direction of the reel channels.
Keep repeating this pushing /feeding action, it is surprising quick to load a whole film. The even pressure on both side of the indent prevent the film from popping out of the guide channels.

You can only move a small amount of film the length of the indent at any one time, but it is surprising quick to load a whole film. The even pressure on both side of the indent prevent the film from popping out of the guide channels.

From time to time release more backing paper away from the film and reel to make it easier to push / feed the film into the reel. You can feel the film edge traveling deeper into the reel at the indent.

Keep push / feeding the film until you come to the end of the film where it is taped to the backing paper. Carefully tear the backing paper from the film, taking care not to kink the film or dislodge it from the reel.


Leave the sticky tape on the film and fold its sticky edge down onto the under side of the film.

Push/feed the remainder of the film right into the reel so that the taped edge is under the guide lips.

You are just about done. Load the film reel and central column into the daylight tank. Place the lid on top and secure. Turn on the lights or remove the tank from the change bag. You are now ready for processing 120 film in the tank under normal room light.

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