Stouffer TLF2115, 21 step transmission guide, increment 0.15 - extra large
Stouffer TLF2115, 21-step transmission guide, extra large
21 steps, increment 0.15, 8 x 10", Dmax 3.05
Step-Wedge TLF2115-Data
21 steps, increment 0,15, Dmax: 3.05, size 201 x 254 mmThe Stouffer 21-Step Transparent Guide is heralded around the world as "the platemaker's choice". The TLF2115 - extra large version is used to calibrate scanners, exposing machines, densitometer but also serves as a gauge to evaluate the variables encountered in the exposure and processing of lithographic plates and photographic materials by contact. If indicates the direction and magnitude of exposure or processing adjustments necessary to achieve the desired results. It is also used with contact positives, silk screen, printed circuit boards, and most other photographic applications for judging results, determining speed and contrast for emulsions, and hardness of coatings. Stouffer has a wide range of transmission step wedges that are used in the various industries requiring photosensitive quality control devices. Several sizes and formats are offered to meet most needs.
RoHS-Compatibility:
Products manufactured and sold by Stouffer Industries are RoHS compliant. All step wedges, step tablets, gray scales, and any other photosensitive quality control device made contain no or less than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants.
Longlivety:
Stouffer Step Tablets and Gray Scales are made under controlled conditions to meet or exceed the requirements for archival permanence following procedures recommended by the manufacturers of the materials. Archival permanence is usually defined up to 10 years or more. Studies at the National Institute of Science and Technology have shown that the densities of this kind of step tablet will remain stable for at least four years when handled and stored with care.
The primary causes of degradation are use, followed by ( in no particular order) heat, humidity, fingerprints, splashes including spittle, chemical fumes and vapors, attempts to clean the emulsion with anything other than a soft camelhair brush, and abuse.A quality control device that is handled 40 times a day will degrade faster than one that is handled once a week. The user should set a routine to determine the frequency of replacement based upon factors occurring in-house and the foregoing discussion.
We recommend to change the step wedge after 3-6 months and immediately at visual damage
Calibration:
This step wedge is also availabe in calibrated version.
Specification
How to use the Stouffer T2115 Greyscale
(for other step wedges must be recalculated following density steps)Set your contact printer or vacuum frame to make several trial exposures on separate pieces of film, with each exposure for a different length of time. Make three exposures: one determined by past experience or the exposure normally used in daily production, one for less, and then one for more. It may be necessary to repeat this testing procedure using different exposure times. Process the test negative for the time and temperature recommended by the film manufacturer. It is important to keep processing consistent. Examine the step tablet/wedge image on each of the negatives. Select as the best the negative in which step 7(on a 21 step wedge) is developed to a dense black, with step 8 only slightly dense. Step 7 will be the aim point for normal copy.
There are many different ways for exposing plates. There are an abundance of different exposure systems and processing techniques. The one constant is the step tablet/wedge. Use the step tablet/wedge as a benchmark for all exposures to achieve accuracy and repeatability.
To find the exposure factor to hold more or less on the Stouffer 21 Step Platemaker Sensitivity guide, follow the chart below.
| to change exposure | 1 Step | 2 Steps | 3 Steps | 4 Steps |
| increase exposure | 1.41x | 2.00x | 2.82x | 4.00x |
| decrease exposure | 0.71x | 0.50 | 0.35x | 0.25x |