burkphoto Loc: High Point, NC

Scanner resolution is measured in dots per inch (cells per inch, really, scanned off the film or print). At 100%, each dot scanned becomes a pixel in the file. Dots have dimensions, but pixels just have RGB color values. Pixels can later be reproduced with dots, using a printer or monitor.

The SIZE of an image within a file (not an image file itself!) is measured in pixels (X by Y pixels). The resolution header in the EXIF metadata of a JPEG is for the graphic arts industry... It tells software how big to make the pixels when opening the file. Originally, it was an indicator of the scanner's dpi setting. But now, you can change it in software to any value you like.

The resolution header of an image is mostly irrelevant in photography. The absolute number of pixels in each dimension of a file coming straight from the scanner (at 100%) or from a camera is what determines how big you can print it without interpolation. Scanners have maximum optical resolution ratings. Those tell you how many dots per inch of original can be converted directly to file pixels.

Digital cameras are a little different. The resolution is only realized after a raw image is converted to a bitmap image of some sort. You might have 6000 by 4000 pixels in a file, but it probably took a few more photo sites or sensels on the sensor to provide the data to post-processing firmware or software that can convert that raw data to an image file. Typically, each pixel is derived from quite a number of adjacent sensels, using a sophisticated algorithm. Each sensel is covered with a color filter, and probably a lens. It takes two green and one blue and one red sensel, matrixed with adjacent sensel values, to make one file pixel with an RGB value.

Scanners can reach very high resolutions. When scanning large sheet film (4x5, 5x7, 8x10...), they can make HUGE files with tens of thousands of pixels in each dimension. From 35mm, 6000x9000 is about the maximum common size.

Neilhunt

Scans or photos of negatives will generate a negative image.
What are you all using to convert your negative image into a positive image?
Seems to me that isn't so easy...

MT Shooter Loc: Montana

Scanners automatically convert negatives to positives when scanned, along with color corrections for faded or color shifted negatives.

burkphoto Loc: High Point, NC

Invert curves in Lightroom. Adjust once for a particular film type, using a macro copy of a “normal” negative. Save a preset. Use that ONE CLICK preset for the next neg. then tweak as needed from there.

burkphoto Loc: High Point, NC

Scanners with 48- bit color can save 16- bit TIFFs. ACR in Photoshop or Lightroom does a great job with them.