[acoufap]

I guess you refer to LCC profiles, @ivanvernon, and I think you're not the only one who doesn't know what I'm talking about. So I'll try to explain it in some words.

LCC (Lens Color Cast) profiles help to remove vignetting, partial shading and color casts of images. They also can help to remove sensor spots automatically.

If I remember right this method was developed by Phase One for technical cameras where tilt / shift can lead to varying brightness distribution within an image. But this technique also can be applied to every lens to get rid of the mentioned technical weaknesses.

Principle:

• You take two images (raw) of your composed scenery with exactly the same parameters.
• The first one you take through an opal glass like the one you see in the black & white image I posted. Let's call this image "opal image".
• The second one you take of the scenery. Let's call this image the "scenery image".

Capture One Pro delivers an LCC-Tool. It looks as follows:



What does this tool?

Applying this tool to the opal image generates LCC correction data based on some parameters - this opal image get's an LCC tag and represents the correction that can be applied to other images. Now you connect (apply) your LCC-profile opal image to the scenery image. The corrections are then applied the scenery image.

So if you go this route you get your scenery image corrected individually for your camera-lens combo with it's settings, especially focal length, aperture, focus, ... It doesn't everything a special lens correction profile does (no distortion and CA correction) but some of it and a little bit more (color cast and spot removal - if selected within the LCC tool).

I recently did some test shots to get material for a blog post that I'm writing for my website. I show some of this material so that it's going to be more clear what I'm talking about. Strong light came from the left side. K-1 and DFA28-105 at f/11. 100mm Haida filter system was attached, PLC filter inserted.


Opal image. The technical setup clearly produced a shading. Looks like a GND filter was inserted ... I hope not!


Scenery image taken.


Opal image after applying the LCC tool. The image gets a LCC tag within Capture One Pro.


Scenery image after applying the LCC profile to the scenery image. No digital GND applied!

There are clearly nice benefits and it can be used with every camera that's supported by Capture One and it can be used with every lens you can think of!

Disadvantage: you need a little bit more time and double memory space. If you like to work slow and get great image quality, it's IMO a great tool.


I'd be happy if I could help you and others to understand what I'm talking about.

P.s. I don't know if there are other Raw Converters that offer such a tool.

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Last edited by acoufap; 11-20-2020 at 11:25 AM.

[Erictator]

Our feathered friend finally decided to take a shot at grabbing breakfast


Pentax K-1 HD PENTAX-D FA 150-450mm F4.5-5.6ED DC AW ƒ/7.1 450.0 mm 1/2000 iso250


Pentax K-1 HD PENTAX-D FA 150-450mm F4.5-5.6ED DC AW ƒ/7.1 450.0 mm 1/2000 iso200


Pentax K-1 HD PENTAX-D FA 150-450mm F4.5-5.6ED DC AW ƒ/7.1 450.0 mm 1/2000 iso200


Pentax K-1 HD PENTAX-D FA 150-450mm F4.5-5.6ED DC AW ƒ/7.1 450.0 mm 1/2000 iso200

Unfortunately he got soaked all for nothing

Pentax K-1 HD PENTAX-D FA 150-450mm F4.5-5.6ED DC AW ƒ/7.1 450.0 mm 1/2000 iso200

[ivanvernon]

Couple of shots with the medium format Carl Zeiss Jena Biometar 80mm f 2.8.

[Buckeyemikie]

I'm posting a series of shots of the milky way with some hoodoos in the foreground. This is from my October trip to the Bisti/De Na Zin wilderness in north eastern New Mexico. We stayed late to shoot the milky way behind the silhouettes of the hoodoos. In post, I noticed a bright star rendered as a perfect 8-pt. star. It was the only one so rendered. It was taken at 9:10PM with my FA*24 on my K-1. The settings were 15sec. @ f4.0. Subsequent shots show the same star but with fainter star bursts and then none at all. The last shot was taken at 9:26. In this shot the star burst is virtually gone. The shutter speeds were between 10 & 15 sec & the apertures ranged from f2.0 to f4.0.

What kind of star is this? I could be wrong, but I don't think the shutter speeds or apertures account for the significant differences in the star burst effect. Thoughts anyone?

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[nightfly]

Jupiter is the "star" in question. Significantly brighter than the other point sources. This contributes to the effect.

[photoptimist]

I'm posting a series of shots of the milky way with some hoodoos in the foreground. This is from my October trip to the Bisti/De Na Zin wilderness in north eastern New Mexico. We stayed late to shoot the milky way behind the silhouettes of the hoodoos. In post, I noticed a bright star rendered as a perfect 8-pt. star. It was the only one so rendered. It was taken at 9:10PM with my FA*24 on my K-1. The settings were 15sec. @ f4.0. Subsequent shots show the same star but with fainter star bursts and then none at all. The last shot was taken at 9:26. In this shot the star burst is virtually gone. The shutter speeds were between 10 & 15 sec & the apertures ranged from f2.0 to f4.0.

What kind of star is this? I could be wrong, but I don't think the shutter speeds or apertures account for the significant differences in the star burst effect. Thoughts anyone?

Nice pictures!

Two answers to your questions:

First, starbursts arise from diffraction effects between the incoming light and the straight edges of the aperture blades inside the lens. Because this diffraction effect is very weak, it only appears around over-exposed objects such as bright stars, headlights at night, or the sun. The length and intensity of the starburst rays will vary with the brightness of the light source and thus also with the shutter and aperture settings. On most lenses, starbursts only appear when the lens is stopped down a bit because the wide-open aperture is usually a perfect circle that does not make starbursts. In many lenses, stopping down more (and increasing the shutter time) will also strengthen the starburst effect because when stopped down, the lens aperture is more like a polygon than a circle.

Second, the bright star in the first image is not actually visible in the other two images. It's behind the hoodoo. The brightest star in the second two images is the same as the less-bright star in the first image that is to the left and up a bit from the star-burst star. (You can confirm this by carefully noting the patterns of stars around the bright star in images 2 and 3 and then matching that to the pattern around the second brightest star in image 1.)

[Buckeyemikie]

Nice pictures!

Two answers to your questions:

First, starbursts arise from diffraction effects between the incoming light and the straight edges of the aperture blades inside the lens. Because this diffraction effect is very weak, it only appears around over-exposed objects such as bright stars, headlights at night, or the sun. The length and intensity of the starburst rays will vary with the brightness of the light source and thus also with the shutter and aperture settings. On most lenses, starbursts only appear when the lens is stopped down a bit because the wide-open aperture is usually a perfect circle that does not make starbursts. In many lenses, stopping down more (and increasing the shutter time) will also strengthen the starburst effect because when stopped down, the lens aperture is more like a polygon than a circle.

Second, the bright star in the first image is not actually visible in the other two images. It's behind the hoodoo. The brightest star in the second two images is the same as the less-bright star in the first image that is to the left and up a bit from the star-burst star. (You can confirm this by carefully noting the patterns of stars around the bright star in images 2 and 3 and then matching that to the pattern around the second brightest star in image 1.)

Thanks for the explanation & the comment. I always thought a strong starburst only happened at small apertures.

[fs999]

FF Mode • 100 ISO • Porst Tele 1:1.8/135mm MC AUTO E


FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM


FF Mode • 100 ISO • Irix Blackstone 15mm F2.4

[WPRESTO]

Utah, as I've typed before, is covered by scenery

[Bonner04]

November 20, 2020
Ojai, California
Pentax K-1 Mark II Silver, Pentax smc P-F 35-105mm f/4-5.6
f/8 1/60 ISO 800

[aaacb]

[fs999]

FF Mode • 800 ISO • Sigma Art 18-35mm F1.8 DC HSM


FF Mode • 100 ISO • Sigma Art 18-35mm F1.8 DC HSM


FF Mode • 100 ISO • Pentax FA* 24mm F2 IF AL

[Rondec]

A Stillness Before Sunrise (DFA 24-70mm/pixel shift)



Country Road (FA 31 limited/pixel shift)



Fallen Barn at Dawn (FA 31 limited/pixel shift)

[stubyles]

A few from Tokyo with the K150/4:

[mattb123]

K-1ii & 15-30