(Using Negative Lab Pro 2.3, scanning with Negative Supply 99CRI light and Canon R5 in RAW.)
Hello! I recently started using Negative Lab Pro last month and have loved the results so far. I just have one question: I have noticed that changing the exposure of my R5 while scanning has a profound impact on the colors of the film.
I’ve attached these two photos as an example. One photo was slightly over exposed on the R5 while one was slightly under (nothing clipping, lots of detail there.) Both at ISO 100, f11. As you can see, the color luminance and saturations vary quite a bit between the two. The photo which was a bit overexposed (right) has lighter blue tones but darker reds, while the underexposed one is the opposite. The difference looks much more extreme when you toggle between the two than side by side, but it will only let me upload one at a time.
Note the difference between these two was probably only about 1 or 1.5 stops in camera. I also didn’t touch anything besides just hitting convert. Anyone understand what mechanism is causing this? Is it something to do with the response curve of my R5 or the way in which Negative Lab Pro analyzes the image? What exposure would I use in order to obtain the most “accurate” color values. This isn’t necessarily an issue for me but I would like to understand the process.
Hi Jacob i will try and help. You seem to be wanting to establish in this forum, optimum exposure for your film, development,
scanning and presumably, display option/s for your workflow.
Im not sure this can be responded to specifically - there are too many options. The first recommendation would be to shoot a colour target with known chroma and luminance values (brightness is separate from colours as you know) on the day/time of your shoot and then get that processed along with the rest of your scene-exposed film. Suggest half stop increments in the same light as your subject, maybe to 1.5 under and same over ‘meter averaged’. Then take the scanned negs and process them through the target software, and save the profiled file (for that scene) and then scan your scene neg and apply that saved preferred profile. You will not make any visual sense of this unless your monitor is also properly profiled. When it comes to output, you need the same process. Of course, great colour images were made well before this kind of tech, and you could read about the work-practices of Saul Leiter, William Egglestone, Garry Winogrand colour, et al - those who pushed colour through the 1950s - 80’s and their evaluation almost always was a final print stage, under gallery lights or on the printed page. A final point is that they rarely posted comparative images. They found what they liked and went with that. Hope this helps ?
For me this is more of an exercise in refining the optimum ‘scanning’ exposure with your camera. I downloaded the jpeg and brought it into Lightroom, then created a virtual copy and isolated left & right versions so that I could use ‘Compare’. Using the WB Selector on the sign and adjusting the exposure very slightly the sign was essentially identical in each. Even so the contrast between the sky and the sunlit top of the building was still stronger in the RH image so for me this would be my ideal exposure and the LH image, 1.5 stops less exposure than the RH, was indeed a little under-exposed. As Jacob says you are looking for a starting-point and may well want to change things slightly but I think that NLP has done a great job, in both cases actually, but for me the RH image would be a better starting point.
It would be interesting to see a representation of the two original unprocessed shots of the colour negative before they went through NLP, extra work for you though.
