RAW files underexposed – Fujifilm

[Amine]

Hello Nik,

First, amazing job on Nitro, coming from RAW Power the features are great but Nitro has a little UI touch and little details that are a pleasure to use.

Quick question about something odd with my Fuji files.

I noticed that the RAW files in Edit mode are way “too dark” compared to the embedded JPEG that is displayed before going to edit mode. I tested on a Fuji X-Pro 2 without any exposure compensation, all default settings, the raw in edit mode in Nitro is 2 to 3 stops or more down, which is not fixable by adding more exposure it clips the whites.

The very odd thing is that I downloaded an old sample image from here and tested again, and that one doesn’t have the issue my files have.

The second odd thing is that I noticed that the EXIF infos that Nitro can read from the sample RAW is much more complete than the ones it reads from my files. I tried to use everything auto, and all settings to 0, always the same issue. I also tried with compressed / uncompressed RAW, issue seems to be the same.

Thank you.

Note :
– My camera uses the latest Fujifilm firmware.
– The RAFs coming from my camera are correctly displayed in capture one / lightroom.

[Nik Bhatt]

It’s very hard to tell what is going on based on your description. Please email support@gentlemencoders.com so I can help you. The forum isn’t the best “forum” for bugs like this. It’s more for discussion and general questions.

[Amine]

OK, I will email the details.

For other people who might come up here later with the same question, did some more testing and found this: the combination of anything superior to DR100 + compressed RAW seem to have an influence.

– Nitro/RawPower seem to not see all the EXIF data when the RAW is compressed.
– So maybe, it doesn’t see the exposure “correction” that fuji writes in the metadata.
– Since dynamic range setting (DR200 / DR400) does underexpose the shot, if Nitro can’t see the EXIF, it can’t know that the short was underexposed then corrected.

When shooting uncompressed RAW + DR100 : exposure in Nitro seems OK. If compressed OR >DR100 the issue comes back.

Thanks Nik for the quick reply.

[Nik Bhatt]

You might try a quick Auto Levels / Auto Curves on the image to see if it improves the appearance. I suggest the Auto Black button (the first one).

[thewildrover]

I don’t know if this helps at all, as I only have a few Fuji RAF files in my collection from a few years ago. However, it may point to something.

The cameras I owned were the old EXR sensor models, and from those I understand that Fuji likes to use wacky designs of sensor. I know these have been a continuous cause of headaches for me finding software that can deal with them. The only ones that ever did were the Fuji proprietary software, and Lightroom.

As I understood, they used a strange diagonal hexagonal (it might have been octagonal, I can’t quite remember now) array. It was also possible to take shots that split the sensor arrays into two separate images, that were later ‘stacked’ to create an enhanced image. There were a couple of options, the most common was for low light, where it stacked a pair of under/over exposed images (the data was hidden inside the RAF file), and merged them (either in the camera, or using the Fuji software) to reduce noise. Or you could just shoot with the whole array for full resolution.

I did find out that some softwares could open and edit the RAF files, but only partially. They would only work with one of the hidden versions, which was usually the underexposed version. Converting to DNG enabled more software to be able to open them such as Photos, but the editing was starting from the underexposed version, and often ended up being grainy, and difficult to get the best out of, and are half resolution (the Fuji software maintained full resolution).

I’m currently actually working on these in Nitro myself, and still see this issue. Although on the ones I’ve started on Nitro has occasionally opened the over exposed version instead. However, when returning to those later, it re-rendered them using the underexposed version, so I had to re-adjust them. That seems to have stuck now.

I believe Fuji abandoned the EXR technology some time ago, but I didn’t know if they’d produced something similar instead.

Anyway, I don’t know if that may explain what’s happening here or not, worth a try :-).

(PS. I never bothered you with this in support, as I realise these are pretty tricky to handle, and not worth the effort for a handful of less popular, and unsupported, cameras in Apple Raw).

• This reply was modified 1 year ago by thewildrover.

[James Muspratt]

Thanks for posting this. I love Fuji but yikes this is uncertain territory.

For the past year I’ve been shooting RAW on my Fuji X-S20 and then converting the RAFs to DNG before importing to Apple Photos / Nitro. I thought that conversion was required for Apple Photos to read the RAWs at all. Turns out…

– Apple Photos can read .rafs if they were shot as Uncompressed
– Nitro can read/edit everything

Secondarily, I’ve been wondering why my DNGs are so dark and what (if any) critical info I’ve been throwing away by converting to DNG. It’s surprisingly hard to get a straight answer on this from the web. But for what it’s worth here are 3 exposures and the 9 files produced from them for comparison.

– My DNGs are always darker than the RAFs
– Lens correction is subtly different across RAF, DNG, and JPG (probably it’s not coming through from RAF to DNG).

Apple Photos (10.0)
https://ibb.co/KhbZcZy

Nitro (2024.10)
https://ibb.co/WcCbD94

(Fuji firmware 3.0.0. Adobe DNG Converter 17.0.0.2043)

[Nik Bhatt]

DNG generally doesn’t lose a lot of information, but manufacturer “secret metadata” is generally not converted (of which there is plenty).

Lens correction can vary and the DNG decode is not the same as the RAF decode, though usually it doesn’t matter that much.

A DNG should look the same between Nitro and Photos – if it doesn’t that would surprise me.

[Andy Goetz]

I did my own experimentation, and it looks like”Raw Exposure Bias” EXIF field is updated when the DR level changes. For my camera (Fuji XT-4), I have noticed the following mapping between DR level and “Raw Exposure Bias” value:

DR100 -> Raw Exposure Bias -0.7
DR200 -> Raw Exposure Bias -1.7
DR400 -> Raw Exposure Bias -2.7

Manually adjusting exposure gets the RAW file pretty close to the JPG preview, however.

I am not a digital photography expert, but from a little bit of internet searching, it looks like it is “normal” for Raw converters to take into account this EXIF field when rendering a RAW file. Because Apple doesn’t support compressed RAW files and Nitro needs to manually add support, is it possible that EXIF field is not getting taken into account?

On my camera I don’t think you can turn off this Dynamic range expansion setting, which means even if I set my camera to DR100, all my compressed RAF files get rendered by Nitro 2/3rds of a stop under. Hopefully I can fix this with a preset, but it would be great if the upcoming improvements for Nitro compressed RAW handling also looked at this issue.

[Nik Bhatt]

Thanks for letting me know about that. If it’s such a simple mapping, then I could look into it. I figured the DR would be more of a dynamic range compression, and it was darkening some areas and brightening others, so an exposure change would not replicate it very well. For your test images, if you move either Exposure of Whites, are you able to get the results you want? Also, what amount do you move each slider for these various DR values?

[Nik Bhatt]

Are you shooting with compressed Fujifilm images? If so, the next update to the app should provide better compatibility with DR. This means that images with DR will change in appearance when you open them in Edit.

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