Cam App - Iphone 15 Pro Max FALSE COLOUR issue

Hi guys,

Been using this device for a week or so now. Looking at contrast ratios and struggling without a light meter. So using false colour.

The issue I have is that the darker colours aren't being represented by dark blues and purples, the colour is green. This is confusing as the darker skin tones should be green, so this is getting mixed with what should be blue and purple

I have attached an image for reference. In total darkness, the colour shows as green.



I have experimented with exposure settings, shutter speed/angle, ISO, aputure is fixed but I have tried other lenses. I have also tried with a rec709 LUT on when in Apple Log mode. I get the same result in colour representation.

I have also tried restarting the phone and the app. The highlights rep of yellows and reds work fine.

Do you know what I could be doing wrong here, or how to solve this?

Thanks

TL;DR - my false colours are showing all in green in the darks and blacks, where it should be blue and purple.

May I suggest to give the CinemaP3 app a try? It has much better measuring instruments, including false color. And it's not a subscription.

IMG_1577.jpg (213.06 KiB) Viewed 458 times

Will have a look now thank you!

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I'm having the same issue as 'GordonBennett' in the first post.

This is my first time on the forum, so hopefully the images I'm attempting to post below will show up.

Shown below is a screen shot from the app with ISO set to 800. Of particular note is the completely dark/black room on the left and right, as well as the dark wooden frame on the full-length mirror to the left of the lamp on the table.



Shown below is the same image in False Colours. Note how the completely dark rooms and the dark frame are in bright GREEN (18% Middle Gray)- when you would expect them to be in PURPLE (BDL: Black Detail Loss or even NBDL: Near Black Detail Loss). Areas you would expect to be Middle Gray'ish instead appear to be in a bright pink/magenta color which I can't quite correlate to the IRE scale. Perhaps this is some variation of the pinkish MG+1 spectrum? (I never see anything resembling the bluish purples of the NBDL whether I'm pointing at the sun, in a completely dark closet, or anything in between.)



Show below is a carved-out split-screen image to help illustrate the issue. I would expect to possibly see some bluish color somewhere on the screen and the darkest areas to be a vesion of PURPLE (not GREEN).



If I DARKEN the image as low as it can go, by setting the ISO to 55, the GREEN increases dramatically, as shown below...



If I completely cover the lens so that absolute NO light gets through, then the entire image turns a bright GREEN when I would have expected a dark PURPLE.



I appreciate the previous post to try CinemaP3, but I'm a Blackmagic kind of guy and would really love to stick to the Black Magic app. Like Gordon, I've tried all different kinds of settings, LUTs, no LUTs, etc. I'm sure I've turned every setting on/off or min/maxed several different times.

I guess what I'm really hoping for is that if others come across this post, they might be able to confirm they also have this issue. I've attempted to search high-and-low for any information - using as many search terms as I can think of - and so far have come up with nothing. If you happen to run across this post, could you leave a comment if you're having the same issue so we can tell if it's not just some weird issue only affecting me... and Gordon?

I'm on an iPhone 15 Pro Max with iOS Version 17.4.1 using Blackmagic App version 1.3.00111.