Text files are the heart and soul of the single pass offerings from MegaVision. Text files control the look and feel of images shot with the S2 and S32 cameras.
Text files are how we control density range and gamma (in lay photo terms, saturation and contrast). The selection of a text file will render to the image certain attributes that, if less than satisfactory, can be replaced with a different rendering through the selection of a different text file. Text files currently come in two varieties: fleshtone rendering and still life rendering.
Each text file is unique to each camera. Each CCD chip, with 4 to 6 million pixels, has its own “fingerprint” because no two chips have the same sensitivity for each and every pixel. A text file’s name starts with the number of the camera and ends with parameters appropriate to that file’s rendering intent. For example, consider 970745d25p1x2.txt:
970745: camera #45 made in July of 1997
d25: density range of 2.5
p1x2: improved color rendering of early 1998
Each filename tells the user what the text file does. Some files are linear, some do a great job with general color, and some are built for skintone rendering.
In our quest for great color we discovered that our camera did not do a great job with fleshtones when the color was adjusted for the most accurate rendering of our default color target, the Macbeth Colorchecker. Additionally, we discovered that the accurate rendering of fleshtone was not always appreciated. People generally like to see themselves rendered warmer than they really are, especially if their fleshtone tends toward reddish hues. As a result, we have two fleshtone text files, skin2 and skin4. In general use, skin4 is the text file to start with. If the red generation within a skintone rendering seems a little too saturated, redevelop the MEGA file with the skin2 text file. We have also discovered successful fleshtone rendering is cultural. The asian culture prizes the high-valued diffused look common to the fashion photographs of the 1970’s. Do you remember shooting with white diffusion, overexposing the negs, and then printing with a stocking under the enlarging lens? That’s the look they like, not unlike the appearance of the Geisha girl.
Text files work on MEGA files. MEGA files are generated by shooting into a tethered computer or by using PhotoBatch to make a MEGA file from a raw BatPac™ capture. You may find the saving of the MEGA file to be a good idea; it will allow you to redevelop the photograph differently with the selection of a different text file if you don’t like the rendering a given text file produces. All you have to do to get the new rendering is make a selection of the different text file. Choose Setup>Preferences>S2 (or S32) Data File. Navigate your way to the PhotoShoot™ folder, select the S2 Data folder, and choose the text file you’re interested in trying, click Open to make the selection and choose OK to quit the Preferences dialog box. Click Camera to select a MEGA file for development to TIFF. Click the image you’d like to develop and click Develop. Evaluate the rendering of the new text file.
Be aware that text files work exactly like graded B&W printing paper. The files are not designed to retain blown out high values. If you’ve overexposed a scene, the selection of a different text file will not save you any more than selecting a grade 2 printing solves overdevelopment of a negative. Like graded printing papers, text files will modify the contrast and saturation of an image whose high value was properly exposed. Select text files to change contrast between highlight & shadow. Modify color saturation with text files. Do not expect poorly exposed reflectances to be saved merely by selecting a text file.
You will find the text files an easy and simple way to select transition of tone for your images. After development, evaluate remapping of important reflectances in your scene. Generally you will want to keep remapping to a minimum. It’s OK to remap high values higher and low values lower. Try to not remap low values higher and high values lower. Mapping high values lower results in a graying that looks like what results when you try to burn down a high value when printing Plus-X Pan film. The high value doesn’t simply render lower, keeping the detail you see in the neg. It goes gray. And flat. The same is true of remapping high values lower with a curve function-- try not to do it. Low values respond a little more favorably to remapping up than high values down. However, noise generation is always possible. If you do need to remap low values up, carefully evaluate the noise generation. If you can, consider a fuller fill light to obviate the upward remapping of the lowest values. Your images will look better for it.