Friday, October 5, 2018

paradise is a place... in Rhodes!

Cafe Paradise is a small tavern - Cafe restaurant in Rhodes, Greece located in Glyfada beach. The Cafe is located in north part of the island and you need around one hour to reach it. After traveling this long distance you will find the restaurant located near the beach. The Cafe is operated by an old couple and one family friend and it has extremely low prices compared with other shops. Although I don't recommend entering the sea, the landscape view is fabulous and worth the time to travel there as you can see from the photos:

Glyfada beach, Rhodes, Greece.
Glyfada beach, Rhodes, Greece.

Glyfada beach, Rhodes, Greece view from the Cafe.
Glyfada beach, Rhodes, Greece view from the Cafe.

Glyfada beach, Rhodes, Greece.
Glyfada beach, Rhodes, Greece.

Paradise Cafe, in Glyfada beach, Rhodes, Greece. View of the inside.
Paradise Cafe, in Glyfada beach, Rhodes, Greece.

Tuesday, August 7, 2018

Processing Black and White pictures with RawTherapee: Play Raw - Rio de Janeiro

Sometimes all you need a good picture, some editing in the lighting and then you get one very dramatic picture. The photo was taken in Rio de Janeiro, Brazil by gadolf (Gustavo Adolfo) and posted as part of the Play Raw competition. You can find the original RAW files here

I used all the basic editing tools of the RawTherapee to increase the contrast and make the picture to look much more dramatic. You can find the pp3 file here.

Sunday, June 24, 2018

Processing a High Dynamic Range raw image with RawTherapee

Editing High contrast images is hard because you have at the same time to decrease the highlights, increase the dark areas, and at the same time keep the natual colours. Although not always possible, shooting RAW always helps. The RawTherapee offers a plethora of tools to "fix" your images. To illustrate the tools available in RawTherapee, we will edit a picture taken by Ivan Sagalaev and released under CC license in the Play Raw competition of the forum here.

Image after importing to RawTherapee.
Image after importing to RawTherapee.

Step 1: Preparation. First we fix the distortion (if exists) in the Transform tab. Before start editing we always try to fix possible distortions of the image.

Initial Histogram of the picture.

Step 2: Editing the light. 

The second step is to press the "Auto Levels" button in the Exposure tab. This will light the dark places of the picture, but it is not enough.The sky now is it much lighter than before and the colors washed out.

Exposure settings in RawTherapee of the image to recover the dark areas.
Exposure settings in RawTherapee of the image to recover the dark areas.

First we have to fix the highlight of the sky. We increase the exposure compensation and at the same time the Highlight compression to avoid possible over exposure.

Second, we can decrease slightly the Highlights in the Tone curve.  Moreover, we can also increase slightly the Contrast in the same part of the settings.

The third step is to apply negative graduated filter. By selecting negative strength we actually add more light. We set the angle to -174 to highlight only the dark areas.

Negative Graduated Filter settings of RawTherapee to insert more light in the picture.
Negative Graduated Filter to insert more light in the picture.

Next we apply Tone Mapping to slightly improve the dark areas. We only need small amount (0.01) of strength to make the picture to look natural.

In the Detail tab, we enable "Impulse Noise Reduction", "Noise Reduction", and "Contrast by Detail Levels" to increase local contrast. In addition, we can enable the Defringe to improve slightly the color accuracy in the edged of the objects.

Step 4: Editing color. 

Vibrance settings of RawTherapee.
Vibrance settings of RawTherapee.

Finally, in the Colour tab we set the "Vibrance" to 20 to improve the liveness of the color. Additionally, we can decrease the Blue channel in the "Channel Mixer" area to decrease the impact of the blue color in the picture and make the picture more warm.

Decrease the blue channel in the settings for the color.
Decrease the blue channel in the settings for the color.

As a bonus we can increase even more the contrast with the L*a*b* Adjustments and make the blues darker. Thsi is not always welcome from all the people, but I liked it anyway.

The final image after the editing.
The final image after the editing.

Sunday, May 6, 2018

Processing high ISO night images with RawTherapee

Earlier this year i did some videos (here and here) regarding how to remove the noise from high ISO raw images. I decided to write down the work flow with text and pictures to avoid the seeking the video in different parts.

The original file is available here: and the image is taken by PkmXDec using a Sony A6000 + Canon FD 85mm f/1.8 S.S.C. + Lens Turbo II wide open.

Out of the box, the picture shows a lot of noise and the color is too warm if we press the "Auto Levels". This happens because he ISO is 12800 and the lighting available: sodium light. In addition, the color noise has a specific noise pattern, as shown in the uniform part of the picture on the left.

Initial raw image conversion using the default options.
Initial RAW image conversion using the default options.
1. Our first approach is to change the Demosaicing method from the "RAW" tab. The "RAW" tab contains all the options responsible from converting the image from the RAW format to actual picture. This is the first step of process flow before applying any advanced filter or changing the color temperature. In this tab, we change  the AMaZE to LMMSE method. We also change the enhancement steps to 6. The image now has slightly better color noise. An alternative method to use in high noise pictures is the IGV.

RAW image after using the LMMSE method. Notice the reduction of color noise.
RAW image after using the LMMSE method.
Notice the reduction of color noise.
Moreover, Chromatic Aberration in the same tab (Demosaicing) can fix possible chromatics aberrations in the picture. We select "Auto-Correction". Finally, we can also enable the "Hot pixel filter" and the "Dead pixel filter" under the "Preprocessing" set of options.

Demosaicing method options of  the RawTherapee when processing high ISO images.
Demosaicing method options of
the RawTherapee when processing
high ISO images.
2. Next we have to fix the white balance from the color tab. We decrease the temperature to 2451 and we enable the vibrance with a small value (13) to improve the unsaturated colors. We may improve the color in the final phase of our editing.

White balance of the RawTherapee.
White balance of the RawTherapee.
3. The next important step is the noise reduction from the Detail tab. There are two noise reduction methods: The normal and the impulse. We initially enable the "Impulse Noise Reduction" with the default settings. We expect to see a small improvement in random white and black pixels appearing.

Next we enable the "Noise Reduction". We change the Mode from "Conservative" to "Aggressive".  We will notice the difference in color noise, but we have to modify the luminance reduction to achieve better results. We change the "Luminance control" to "Curve". Now we can decide how much noise reduction we want depending on the light available. As generic rule, the dark parts of the
picture contain more noise, so we have to increase the noise reduction. We also increase the "Detail recovery" to improve the details of the picture and decrease the impact of noise reduction.
Noise reduction options of  RawTherapee for high ISO RAW images.
Noise reduction options of
RawTherapee for high ISO
RAW images.
Now even with enough noise reduction, we still have some artifacts. To remove them, we can apply the "Median Filter" from the same tab. Due to high noise of this picture, we select "5x5" Median type and "Weighted" Median method to eliminate also the remaining color artifacts.
Median Filter options for the noise reduction of the  RawTherapee for High ISO RAW images.
Median Filter options for the noise reduction of the
RawTherapee for High ISO RAW images.
4. With noise reduction, we also loosing vital information of the image and we decrease the overall clarity of the picture. To fix this we enable the "Contrast by Detail Levels" from the same tab.  We have to add a bit only to avoid the artifact generation in the picture.

Contrast by Detail Levels of  the RawTherapee.
Contrast by Detail Levels of
the RawTherapee.
5. Finally, we adjust the light and the contrast of the picture. The produced histogram show that the image needs more contrast. In this particular photo we decrease the shadows, we decrease the Exposure compensation to 1.2 and increase the "Black" value to 980 to emphasize the black in the picture.

Final image after processing with RawTherapee.
Final image after processing with RawTherapee.

Saturday, April 21, 2018

Processing Milky Way in RawTherapee

This text is an analysis of a video I did some months ago how to process photos of our Milky Way in RawTherapee. You can find the picture here. The photo was taken by wiegemalt. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.


Step 1: Fixing lighting

Noise in a photo with high ISOThe first thing someone notices when opening the picture is the extreme noise due to high ISO used (1600 - check the picture on the right). The first thought is to de-noise the picture, however, if you do that you are going to loose the details of the night sky. The main reason for the high noise is the additional exposure Rawtherapee adds when the 'Auto' button is pressed. In particular, the RT adds +2.4 EV to equalize the picture.

This is Wrong! What we want is to keep the noise down and at the same time bring the stars up. That's why we are going to play with the Tone Curve of the RT.

To adjust the light properly we increase the contrast by creating a nice "S" shape in the tone curve. We have to decrease the shadows and the darks, but at the same time to increase the lights and the highlights. The slight increase of the lights is optional if you want to emphasize the 'cloud' of the Milky Way.

Tone curve settings of RawTherapee

After the adjustment, you will get a histogram similar to following. Most of the shadows are now totally dark and we created a more uniform area in the center allow further editing. Someone can push the settings even more but remember not to overshoot it.

Photo Histogram of Rawtherapee Before editingPhoto Histogram of Rawtherapee after editing

Step 2: Fixing the light pollution using the graduated filter

Graduated Filter of RawTherapee

We observer graduated additional yellow light that increases towards to the trees. This happens due to light pollution created by nearby lighting. To address this type of lighting we can use the graduated filter of the RT. You have to press the button to show the widget to adjust the position and the feather of the filter. Rotate the filter and adjust it to achieve as much more uniform sky.  You can see the difference if you transform the picture in black and white and compare them:

Photo of the sky before applying graduated filter of RawtherapeePhoto of the sky after applying graduated filter of Rawtherapee

After the gradual filter, you can adjust even more the curves and the strength of the gradual filter. The settings will be different depending on the light pollution and to the actual lightness of the picture.

Step 3: Fixing the Noise

The next step is to adjust the noise of the picture. Adjusting the lightness of the picture helped a lot to reduce the noise, but you can't completely remove it due to high ISO used. The first step is to adjust the mode to Aggressive (or High quality in older versions of RT). Then we use Curve as luminance control to allow better adjustment. We want to de-noise the dark areas, but not the areas that contain light. We adjust the curve by increasing it in the dark part and decreasing towards to the right side. In addition, we have to manually adjust the color noise reduction. We have to decrease the value because default settings of RT are really aggressive. You can also increase slightly the detail recover slider.
Noise reduction filter settings of RawTherapee

Impulse noise reduction can be also be enabled using the default settings. I will really suggest reducing the value to something like 26. Note not to overshoot it because you can remove stars from the picture.

Step 4: Increase local contrast

Next, we increase the local contrast by using the 'Contrast by Detail Levels'. A small push can really make the picture more clear, but you also increase the noise, so use it with caution.

Step 5: Fixing the color

Someone will easily say the yellow light is part of the light pollution. However, this is not always true. In this picture, we can decrease the temperature of the white balance in the color tab. We decrease the Temperature to something like 3150K make it less warm.

White balance settings of RawTherapee

Next to remove the yellowish of the left bottom area we are going to use the HSV Equalizer. You can modify each color range differently. We reduced significantly the yellow part:

HSV Equalizer settings of RawTherapee

Step 6: Bonus: Fix the lens geometry

Although not included in the initial video, you can fix the distortions created by the lenses in the Transform tab. There are two settings you have to play with: Distortion correction and Vignetting. For the distortion, you can simply press the 'Automatic' that most cases works well. Vignetting correction requires more experimentation. You can increase the amount and the strength initially to see the impact in the picture. After the initial editing, you can adjust the amount to something normal.

Vignetting correction options of transformation tab of RawTherapee

Final result:

Galaxy in light polluted area after editing with rawtherapee

Saturday, April 14, 2018

Spring time in Rhodes, Greece

Rhodes is one of the best places to be during  the spring. In contrast with the desert-like landscapes of Cyprus (we now have 28*C and still in April), everything is green. Here are some photos from my parents home:

Saturday, February 17, 2018

Black and White editing with RawTherapee

This text is an analysis of a video i did some months ago about transforming a photo from the old medieval town of Rhodes Greece to a more art stylistic black and white. The most


Step 1: Fixing the color picture

Before transforming the picture to black and white, we have to fix some minor things in the color picture. In this particular example, there was some fringing at the top of the picture due to high contrast of the sky. You can find the defringe option under the second tab of the application. Usually, the default settings are good enough without destroying the contrast of the colors:

Defringe settings of the RwaTherapee.
Defringe settings of the RwaTherapee. 

Step 2: Transforming to black and white

Under the color tab there is a separate part called "Black-and-White". There are three different methods you can try for transforming the picture, but i prefer the default and edit the luminance and lighting later from the first tab. You can find the explanation of the different options here.

Black and white settings of RawTherapee.
Black and white settings of RawTherapee.

Step 3: Adding contrast

By using the two tone curves in the first tab, you can introduce more contrast and adjust the lightness of the picture. You have to keep an eye in the histogram to avoid any over exposure of the picture. The final curve usually is a sigma (S) shaped line with modification to add or remove light for the picture. Each picture is different, so select what you like most.

Tone curve of RawTherapee that introduces more contrast.
Tone curve of RawTherapee that introduces more contrast.

Step 4: Insert graduated filter

If you notice, the picture is more exposed at the top, making the lighting of picture imbalanced. To fix this we introduce a graduated filter. After applying the filter, the picture should be more balanced and it will be easier for us to apply the next filters.

Graduated Filter of RawTherapee.
Graduated Filter of RawTherapee.

Step 5: Tone mapping 

The next step is to apply tone mapping to improve the dynamic range of the picture. You can play with the strength of the filter, but remember not to over shoot it. High levels of tone mapping can make the picture really look unnatural. In addition, the latest version of RawTherapee has also the HDR tone mapping that you can play.

Tone mapping of RawTherapee
Tone mapping of RawTherapee.

Step 6: L*a*b* Adjustment

I played a bit with the Lab settings to improve the contrast of the picture even more. I didn't want to modify the tone curves in previous steps, so i decided to play with the Lab setting to introduce more contrast in a part of the histogram using the "L" curve. Not required, but i liked the final result.

Step 7: Vignette filter

Vignette filter is a filter used in many cases to pop the picture by decreasing gradually the light from the corners to the center. Because our picture is already in good shape, we have to only add a touch of the filter. Again, avoid overshooting there, i have seen pictures destroyed from the heave vignetting.

Vingette Filter of RawTherapee.
Vignette Filter of RawTherapee.

Step 8: Noise reduction

The increase of the contrast and the tone mapping strengths the noise that there is in the picture, or worse inserts artificial noise. Applying slightly noise reduction can really improve the image quality. I usually apply the impulse noise reduction with threshold less than 55. The filter can easy remove useful information and decrease the overall aesthetic of the picture.

Step 9: Final adjustments

In the final step, you should go again through the tone curve and other filters to ensure that everything are in place and tune the filters to achieve the most pleasing aesthetic result. Each human is different, so you each one of us can like slightly different settings of the picture. Experiment yourself and you will achieve what it pleases you!

Download example files

You can download the files used for this tutorial the NEF file (~23 MB) here and the pp3 file here.

Monday, January 15, 2018


Limassol is a city on the southern coast of Cyprus and capital of the eponymous district. From time to time I have to visit Limassol for either work or leisure. I 'm always getting impressed from the city beauty.

Exotic Place. Limassol walking area next to the sea.
Limassol walking area next to the sea.

Limassol walking area next to the sea.
Limassol walking area next to the sea. Looks like a tropical place.

Stormy weather view from Limassol.
Stormy weather view from Limassol.