Over-/underexposure indicators

Submitted by ahinterl on Tue, 05/19/2015 - 07:30
Forums: 
General discussion

I'm currently evaluating RawDigger and Fast Raw Viewer (the latter looks simpler and thus better suited to me ;-) ). In the RawDigger tutorials, I've read that the point where clipping in either direction occurs, respectively at what specific exposure level the program is expected to show over-/underexposure, must be determined first by looking at the histogram's ends - what figures are there (spike, waveform,...) and at what x-value they occur. The threshold values then can be entered in the preferences section.
First and foremost, while I understand that basically, I wonder why such a process is required. I can imagine that the bit depth of a camera might be completely unknown and thus the maximum exposure value (such as 4096) can't be determined...
Now that Fast Raw Viewer doesn't look to have a similar feature like RawDigger where the threshold values can be set in preferences, to me it seems that the threshold is more "hard coded" to +3 EV/-5 EV or so.
Can someone please provide more information about this topic?
Andreas

Iliah

Tue, 05/19/2015 - 11:05

Dear Andreas,

First, the full bit depth is not always in use. Better to say, most cameras do not use it now. Second, both RawDigger (as one of the modes) and FastRawViewer offer automatic recognition of overexposure condition. Third, both RawDigger and FastRawViewer allow to set the value for underexposure inprogram Preferences.

l_d_allan's picture

l_d_allan

Tue, 05/17/2016 - 14:34

OvExp enabled when FRV launches?
 
Is there a Preference so that OvExp is Enabled when FRV starts up?

lexa

Wed, 05/18/2016 - 03:44

 

Preferences - Interface - Restore last View settings on program start - will restore all Menu-View checkboxes, including OE/UE (also channels selector, USM mode)

--

Alex Tutubalin/FastRawViewer team

l_d_allan's picture

l_d_allan

Wed, 05/18/2016 - 06:21

Thx ... Default?
 
Should this be the default, at least for OvExp? At least for what I use FRV, I am almost always interested in blown highlights. However, I realize that for the majority of your users, the dominant use-case might be otherwise. That might be especially true since the Feature Request for Thumb-nails / Grid-View was implemented. 
http://www.fastrawviewer.com/node/58 ... from l_d_allan the PEBKAC'er
 
And sorry to have missed that ... I do recall noticing that, and perhaps wondering if it was a "likely suspect".  I did a search of the forum for something related to OvExp and UnExp, so I went ahead and added my Reply to that year-old thread without checking further. My bad.

lexa

Wed, 05/18/2016 - 07:12

We change default behaviour only if it absolutely necessary

In older version FRV do not store 'View' checkboxes state. We've implemented it in some version (1.1?) and do not enable it by default to keep compatibility with older versions.

There are lot of absolutely different use-cases, no way to fit all needs with defaults.

--

Alex Tutubalin/FastRawViewer team

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