post processing – Rec-709 lut, color correction and grading ordering

I recently downloaded some LUTs, and some of them are Rec-709 luts.
From what i’ve read, Rec-709 is some kind of standard that can make images look good on most if not all monitors. I now it is a color-space, but what order is this LUT applied? First or last in the process?
I also wonder if this is a LUT that is not used for color grading, so I have to use another LUT for this?

From what I understand this is the right workflow (roughtly)?

  1. Apply Rec-709 lut
  2. Do color correction (with waveform, vectorscope etc).
  3. Do grading: apply second/last LUT for final touch.

In what order is the best way to do things like this?
Im not 100% sure if stage 1 and 2 should be flipped, or if this is the right order to do things in?

Reason Im asking is that I have some film-footage I’d like to improve using color correction and grading and learning about these kinds of things. Another question i have is can any footage use Rec-709 luts?

Any other suggestions for workflow using two or one LUT are appreciated.

EUR/USD Technical Analysis: Fresh Attempts for Upward Correction – Forex News & Analysis

After a harsh week in which the EUR/USD was exposed to downward momentum, pushing it towards the 1.1688 support, and with the start of this week’s trading, the pair tried to rebound higher with gains to 1.1793 before settling around the 1.1775 level at the time of writing.

However, TopAsiaFX has stated that attempts to rebound lacked strong momentum to stabilize above the 1.1800 resistance, and the efforts of the Euro are hindered by concerns about the strength of the second wave of the Corona pandemic and the measures of European countries to contain the outbreak of the deadly disease.

These restrictions directly affect the European economy, which is still suffering from the consequences of the first wave.

At the same time, and with these concerns, the European Central Bank monitors the economic performance of the bloc to determine its appropriate policy.

In this regard, European Central Bank Executive Board member Yves Mersch said yesterday that policymakers will carefully examine the economic data received before the next policy session to ensure that the impact of coronavirus containment measures is not repeatedly considered in light of extremely unstable expectations.

“Looking to the future, in the current environment of high uncertainty, the European Central Bank’s Governing Council will carefully evaluate the information received, including developments in the exchange rate, while ensuring that this information received, such as information related to containment measures that were included already at our baseline, were only counted once in our assessment.”

He also said that the economic recovery in the Eurozone remains incomplete and prone to setbacks. The policymaker emphasized that the Board of Directors continues to prepare to adjust all its tools, as appropriate, to bring inflation back to its target level.

The UK is leading European efforts to contain the pandemic. As authorities across the UK impose new restrictions on business and social interactions as COVID-19 infections are soaring in all age groups, where parts of the country’s hospital beds and intensive care wards are filling up.

One of their main goals is to reduce the pressure on the NHS ahead of the winter flu season. In this regard, public health experts say that the lockdown could help reset the epidemic to a lower level, giving doctors time to treat patients and providing breathing space for the government to improve its response.

Britain has the most serious outbreak of the Coronavirus in Europe, with more than 43,700 confirmed deaths.

According to the technical analysis of the pair: We are still waiting for the EUR/USD to stabilize above the 1.1800 resistance, for an opportunity for a stronger correction upwards, and we expect the pair to remain stable between the 1.1660 support and the 1.2000 psychological resistance for a period of time, as shown on the daily chart.

The psychological resistance at 1.2000 brings condemnation from monetary policy officials at the European Central Bank, as the Euro’s high exchange rate harms the European economy, which depends on exports at a time when it suffers from the effects of the pandemic. At the same time, the 1.1660 support raises buying interest among currency traders.

As for the economic calendar data, today: The German producer price index will be announced, then the Eurozone’s current account will be released. During the American session, building permits and the housing starts in the United States will be announced.


Change Post text (correction link info)

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coding theory – Error correction code without error detection

Error detection and correction codes require many bits of redundancy for correcting even a modest number of erroneous bits. However, we often have out-of-band methods to determine when and where the errors occured, such as if we observe a voltage spike that exceeds the usual signal levels.

  1. Are there any well-established error correction codes that use less redundancy, but require that the receiver explicitly declares some bits as unknown and corrects only those? In theory, we should be able to correct one erroneous bit for every bit of redundancy.

  2. Are there any such codes which are also able to detect and correct a small number of unknown errors, in addition to the known ones?

  3. Are there any such codes where the receiver augments each bit with some kind of non-binary confidence score, and the code then finds the most likely original sequence?

color correction – How can I create a LUT on Linux with free and open source software?

I use Linux for everything media production. I shoot RAW and process images with Darktable.

Now that I’ve started making videos too (4K ProRes), I need to apply a LUT to them in post. This requires importing a .cube file into Kdenlive. I know how to do that, but I don’t know how to create a LUT.

Can I import a frame of video into Darktable, adjust the colors, and export a .cube file to import into Kdenlive to apply to the video?

Or are there other programs that will create a LUT on Linux? Can GIMP do it?

What Linux program can be used to create LUTs?

diopter – How do I chose the right “correction eyepiece” when I need to go past the furthest left on a Nikon viewfinder?

This prescription is for -1.25 diopters (under “sphere”), plus some astigmatism (“cylinder” and “axis”). You won’t find an off-the-shelf corrective piece to deal with astigmatism — usually we just ignore that.

The add-on corrective eyepiece is designed so the nominal number is the result when used in combination with the existing adjustment in its neutral position, which will be -1 (not 0). So, the -2 diopter seems right; you can then set the adjustment in the built-in diopter a couple of clicks to the positive, so your end result is around your prescription of -1.25.

On rereading several times, I see the source of your confusion.
The prescription tells you the correction you need. You’re thinking that maybe it tells you the error of your eyes and you need the opposite to counteract that — nope. Just get a corrective lens that matches what’s written.

nikon – Why does high brightness affect white balance correction?

Your greycard is not filling the frame. That won’t help at all. Fill the entire frame with it. Focus is not important.

Right now, you have a huge area of ‘not grey’ for the system to contend with.

The whole idea of the white balance preset is that you present it with a known quantity – an 18% grey field, completely filling the frame, in the lighting you intend to use it.
If the lighting is far too bright, even when you’ve narrowed your aperture right down & dropped ISO to 100, then you will need a darker greycard, maybe a 50% grey.
You don’t need correct exposure for ‘a photograph’ when you do this, you need correct exposure for your greycard.

Setting WB needs a grey field, not absolute white. Absolute white is the maximum your camera can record. RGB values of 255, 255, 255. Once you hit that, you are out of gamut. Anything brighter is still all 255s, even if the colour in real life was dark green. If you over-expose it massively, all the camera will be able to record is all 255s… perfect white. There is no balance left to be set with this as input. The camera needs lower input numbers to be able to distinguish how far away from ‘flat’ the colour is.

“White” balance is actually a misnomer in this respect. Instead, think of it as “light grey” balance.

Your photo, btw, looks pretty flat to me, especially in the centre of the greycard. I am puzzled at what you managed to do to it to make it flare out like your top picture… & what you used to do it. Setting WB from it in Photoshop produces no discernible change.

From comments, it appears that the top image was taken after using the bottom image as a white balance measure.
What wasn’t taken into account, therefore, was simply… exposure. It is just massively over-exposed. No amount of white balance will fix that; it’s all pretty much solid 255s with a pale pink border.

I think the ultimate lesson to be learned here is that white balance is not an exposure meter & cannot be used as one. You expose for the greycard specifically. Your actual photographs must be exposed for the actual scene lighting, which will be different.

You can use the exposure meter in the camera to set the optimum lighting for your WB capture. A few seconds after you hit Measure, then Overwrite, your viewfinder goes back to ‘normal’ & you set your exposure to the greycard, the same as for any regular photo [the camera is always in full manual at this point, whatever it was set to outside this mode. Focus is not required [or checked] at all in this mode, as you often have a greycard too small to fill the frame and remain in focus]
Fill the frame with your greycard [fill more than the frame, your viewfinder only shows 90% of the resultant image, so go closer], tweak exposure time, aperture &/or ISO until you hit dead centre on your in-viewfinder metering.
This will set WB to PRE in your regular on-screen display & you go back to setting exposure/focus for your actual photos, as normal.

Can the Nikon D5200 shoot video with white balance correction?

I have a Nikon D5200 and want to use it to shoot video with white balance correction. I am able to shoot photos having saved the a test photo as a white balance preset (page 79 of the reference manual), and I am able to shoot video (switching to live view and clicking on the red button, from page 101 of the reference manual). I am unable to do both and shoot video with the white balance preset from the photo. Page 221 lists all the modes and those that have white balance available, and video does not seem to be one of the modes. On page 245, setting #2 uses white balance and the battery life of shooting movies uses setting #3, which does not use white balance.

Can the Nikon D5200 record movies with white balance correction at time of recording?

How to submit a correction to Timatic?

If I believe that I’ve found an error in Timatic—for example, it claims that a particular document is not required, but I believe that the document is required under applicable laws and regulations—is there any way to ask them to consider making a correction?

olympus – How does camera firmware obtain lens distortion correction parameters?

I use an Olympus MFT system and one thing I notice is that for most Zuiko MFT lenses there is significant barrel distortion as seen in the raw images. However, if you look at the jpg’s, often they have little or no distortion, so apparently it is getting corrected automatically by the camera firmware.

Does the camera (1) just guess at the distortion pattern and apply the same one to every jpg, or (2) does it have some way to detect the lens and have individual distortion correction patterns for particular lenses that it knows about, or (3) does it have some way to detect the distortion by analyzing the image itself and correcting it by image analysis?