Backlight and Night Scene Photography: the light and dark side of life

In this article, I won’t explain known photographic terms in detail, so let’s agree right away that you know the following: “Shutter speed” is the time during which the shutter of the machine is open. “ISO” is the sensitivity of the photosensor. “Aperture” is a number equal to how many times the lens is covered by incident light. “Krop Factor” is a number that shows how much your camera has a sensor smaller than a so-called “full” 35x24mm sensor. Not the number of pixels, but the geometric size of the sensor. “Lens focal length” is the number that is written on your lens. The higher the value of the number, the harder the lens “zooms in” on the image. I realize this is not a scientific explanation, but for now it’s enough.

The first thing we need to understand is what is the dynamic range. Simply put, it’s the ratio between the brightest light and the darkest light in which we can distinguish details and halftones. The dynamic range in nature varies by thousands and tens of thousands of times. That’s why in photography it is measured logarithmically. The so-called “photo steps” differ by a factor of 2 from each other. All devices and our eyes have different dynamic ranges.

For example, for a monitor, the brightest point differs from the darkest point by a factor of 500, which means that it can reproduce no more than 9 photographic steps. And the human eye can distinguish up to 14 steps,.i.e.. The dynamic range of a monitor differs from what the human eye can distinguish by 14 – 9 = 5 steps, or 32 times more than the monitor can reproduce. The camera, in its turn, can record not more than 9 – 10 photo steps in one frame.

In normal daylight the biggest difference between the brightness in the shadows and the brightness in the illuminated area differs no more than 200 to 500 times, so any camera easily captures that. But if you go out at night, the difference between the dark angle and the direct light from a lantern or the moon will be at least 2000 times, or 11 steps. There is often a brightness difference of 10,000 times or 13 steps. So far the camera can’t adequately capture such a brightness interval in one frame, so you often see in your night shots either black areas of the image or overexposed streetlights that have no color or halftones.

The same thing happens when you try to shoot against the sun. You either see white sky and clearly distinguishable details at the bottom of the frame, or conversely, blue sky with white clouds, but everything is black at the bottom. The human eye can easily distinguish such a difference in brightness, both at night and when looking toward the sun for example, at sunset . So our job is to get the camera to pick up adequately both the details in the shadows and the details in the brightest areas.

As has already been said, it is impossible to achieve this in a single frame. Is there a way out of this situation?

The biggest advantage of a camera is that you can change the amount of light you record by changing the shutter speed. T.e. If you increase the shutter speed by 2 times, you will move the brightness by 1 stop. I emphasize – not increase, but shift.

So if you take three shots where the first one has 4 times 2 steps fast shutter speed, the second one has a normal shutter speed and the third one has 4 times 2 steps slower shutter speed, then in total these three shots will not have 9 steps but 9 + 2 + 2 = 13 steps. This is good enough for most night and backlit shot against the light shots. Photographers pioneered this technique over 100 years ago, but at that time the photographic equipment was less sophisticated and it was necessary to stitch several negatives on top of each other and expose them simultaneously.

Now there are several programs for this purpose which can do this job for you. Most of the programs used are Photoshop and Photomatix.

This photo shows how the Photomatix program “blends” several frames taken at different shutter speeds.

Against the Sun” sunrise.

One frame reproduces the bright sky, but all details are missing at the bottom of the frame, and the sky is almost white where the cloud structure is visible. The program “stitches” three frames into one, allowing you to get a well-developed sky, as well as details at the bottom of the frame. Here’s another example.

In my opinion, the most effective way to process an image is to first use Photomatix Pro,.i.e.. It’s better than Photoshop at processing more than three frames, “stitching” them into a single image, works faster and allows you to process many files in sequence. Then you can switch to Photoshop to bring the photo “to perfection”.

Photomatix Pro is one of the most convenient programs for processing photographs with a high dynamic range HDR-images . Developed by the French company HDRSoft. The advantages of Photomatix over its analogs, as well as over the HDR functions of Adobe Photoshop, are the speed of generating the composite HDR-image and the effective mechanism of suppressing ghost artifacts.

Photomatix Pro is able to automatically create an image with an extended dynamic range using the EXIF information recorded by the camera for this purpose , to process and combine into a single photo any number of photos which show the same scene with different contrast ratios. There is no loss of shadows or details. In Photomatix Pro there are six ways of blending several photos with subsequent batch processing.

Photomatix Pro offers two methods for solving problems related to possible loss of detail in light and shadow areas.

– Exposure Blending: Combining several photos with different exposures into one photo with a higher dynamic range.

– Tone Mapping: details in lights and shadows are reconstructed by creating an HDR image which you process in preparation for printing or viewing.

The workflow in Photomatix is divided into two parts. First, a composite 32-bit image with a high dynamic range is generated from user-selected source files. It can be saved as RGBE or OpenEXR and uploaded again in the future. Then the user selects and adjusts the mode algorithm of the tonal conversion of the summary image into an image with a normal narrow dynamic range, which can be saved in 16-bit TIFF or 8-bit JPEG format.

If the metadata of the source files contains complete and consistent information about the exposure used, Photomatix calculates the exposure by itself. If no metadata is available a lens was used that does not give an aperture value to the camera or if it is the same a series of JPG or TIFF files created from a single RAW original is used , the software evaluates the exposure step and asks the user to confirm the choice or to set the exposure interval manually.

Photomatix Rrosu comparison with other programs for HDR processing

(Check the official website of the developer //hdrsoft.com

	Photomatix Pro	Photomatix Essentials	Aperture Plugin	Photoshop plugin	Lightroom Plugin Merge to 32-bit Plugin
Fusion of photos taken with “bracketing” mode	Yes	Yes	Yes	No *	Yes
“Tone Mapping by Detail Enhancer	Yes	Yes	Yes	Yes	No
Further settings for “Details Enhancer” function	Yes	No	Yes	Yes	No
HDR Tone Mapping and Contrast Optimizer	Yes	Yes	Yes	No	No
“Exposure Fusion” with Fusion/Natural	Yes	Yes	Yes	No	No
“Exposure Fusion and the Fusion/Real-Estate exposure method designed for interior scenes with a window view on a sunny day	Yes	No	No	No	No
Finishing Touch tool sharpening, contrast	Yes	Yes	No	No	No
Return to Tone Mapping Fusion	Yes	Yes	No	Yes	No
Fusion method of merging frames Fusion from a single Raw file	Yes	No	No	No	No
Automatic alignment of photos taken in manual mode	Yes	Yes	Yes	No *	Yes
Automatic ghost deletion	Yes	Yes	Yes	No *	Yes
Automatic Deghosting can be set to automatically remove ghost artifacts	Yes	No	No	No *	No
Selectable Deghosting tool for ghost artifact removal	Yes	No	No	No	No
Context help in built-in presets	Yes	Yes	Yes	No	No
Context Help in User Presets	Yes	No	No	No	No
Display options for the specified presets	Yes	No	No	No	No
Save and load custom presets	Yes	Yes	Yes	No	No
Batch processing of photos taken in “bracketing” mode	Yes	No	No	No	No
Batch processing of single files	Yes	No	No	No	No
Automatic chromatic aberration reduction	Yes	No	Yes	No	No
Automatic noise reduction	Yes	Yes	Yes	No	Yes
Maximum number of photos per session in bracketing mode	Unlimited	5	Unlimited	No	Unlimited
JPEG, RAW, and TIFF 8- and 16-bit image loading	Yes	Yes	Yes	Yes	Yes
Opening and saving 32-bit HDR files	Yes	No	No	No *	Floating point TIFF only (Floating Point TIFF
Integration with the free Lightroom Plugin	Yes	No	No	No	No
Application Type	Standalone standalone program	A self-contained, self-contained program	Requires Aperture 2 or higher	RequiresPhotoshopCS2 or higher	Requires Lightroom 4 or higher

(* Starting with Photoshop CS2 there is a merge of photos taken with the “bracketing” mode into a 32-bit HDR file with automatic alignment and read/write 32-bit HDR files. Starting with Photoshop CS5 there is a feature to remove artifacts.

Practical tips for backlit and night shots

What camera is right for this kind of photography?

Any camera that has Shutter Priority mode will do for backlit photography.

Which “Aperture” to choose?

Depends on the subject, but not smaller than f/5 – f/8 is better for night photography, ie.to. Need a clear, sharp picture.

Which ISO to choose?

The answer is a little bit more complicated. Obviously it is better to shoot at low ISO, but to be more specific, at ISO over 2500 noise becomes very noticeable and its elimination will definitely worsen the result. So try not to use an ISO higher than 500.

A little trick

The finer the structure of the object, the less noise you can see on it., i.e. If you are shooting trees, leaves, etc.. You can use 3000ISO, but if you shoot a wall, the sky or a similarly flat object, it is better not to shoot with a sensitivity higher than 500ISO.

Illustration that you can set the ISO sensitivity to a very high value and get a lot of fine detail.

Shoot with your hands or a tripod?

What shutter speed to choose

The formal answer is the shutter speed should be such, that the frame while exposing will not be “blurred. There’s a rule of thumb: The shutter speed has to be faster than the “focal length” of your lens multiplied by the so-called “Krop Factor”.

.I.e. . if your lens has a focal length of 50, cropped ratio of 1.4 like Canon’s 50 series the shutter speed has to be faster than 50 x 1.4 = 70. The closest number to that is 100. T.e. Shutter speed 1/100 sec. If there isn’t enough light at this shutter speed try increasing the ISO to 500, if that isn’t enough then get your hands on a tripod or something else to replace it.

A little trick

If you turn on the “Self-timer” mode on the camera when taking pictures, it will increase the length of shutter speed at which the image will not be blurred.

.I.e. . in the previous example, we had that you can shoot with a handheld shutter speed not slower than 1/100 sec, then if you turn on the “self timer” you can get good pictures at 1/40 sec. It means you can take pictures of darker subjects.

Use autofocus or manual focus

When shooting night scenes it is better to use “Manual Focus”, i.e. to. Often in low light, the auto focus does not work or the focus is wrong.

A little trick

Most night shots are taken with the lens set to infinity. The easiest thing to do is this.

Focus on any bright object at a distance of more than 50 meters. The lens will be set to infinity. Then set the lens to “Manual” mode and it stays in this setting.

Then point the lens at the subject you want.

When shooting with a tripod, you can set the shutter speed to a second or more.

A little trick

Many modern cameras have a “Dark Background Subtraction” mode, which usually activates when the shutter speed is slower than 2 seconds.

This mode reduces noise by several times when taking pictures of night scenes.

So if you see that you need to set the shutter speed to 1 second, then increase the aperture number so that the optimal shutter speed becomes more than 2 seconds.

How to choose the best shutter speed, how much slower it is to take an “over-lit shot” and how much slower it is to take a “darker shot.

There are three principally different ways of doing it. The first way is for cameras in which you cannot see the “Brightness histogram” when taking pictures see the camera manual for the availability of this function and in which there is no “Bracketing” mode.

Modern DSLRs and mirrorless cameras usually have this feature. This is not possible with simple compact cameras. In that case set the camera to “Aperture Priority” mode. Set the aperture to f/5 to f/8 f/8 is better .

Warning! Be sure to use the “Self-timer” or remote control so that you will NOT touch the machine when the shutter is released.Then point it at the subject and note the shutter speed which the auto shutter speed selection shows. After that switch to manual mode “Manual”, set the same value of aperture and shutter speed in it and make a shot. Then increase the shutter speed by two notches and take the “Blown out picture”. Then go back to “slow shutter speed” and take it down two notches. Take a “Dark Frame”.

The second method can be used if your camera has a “bracketing” mode. First set the ISO speed and aperture as described above, then determine the “Optimum shutter speed”. Then turn on the “Bracketing” mode at +/- 2 steps of “Bracketing” and take three frames in automatic mode.

The third method is possible if you can see the brightness histogram on the screen. First do the above steps until you find the best shutter speed, then switch to manual mode and look at the luminance histogram and lower the shutter speed until the brightest parts of the histogram disappear altogether. After that, take a picture.

It will be the darkest frame. Memorize the shutter speed. Then increase the shutter speed until the darkest parts of the histogram disappear. Take the picture. It will be an “overexposed picture. Memorize the shutter speed.

Then add those numbers and divide them by two. The resulting number is the shutter speed for the third shot. For example, if the lightest frame had a shutter speed of 10 seconds and the darkest had a shutter speed of 2 seconds, then the third frame should have a shutter speed of 10 + 2 2 = 6 seconds.

The third way gives the best result.

Little tricks

1. Beautiful “beams” around the bright lights are made because of the narrow aperture. So if you do NOT want rays around the glowing dots from flashlights, then open the aperture. Usually at an aperture of less than f/5, the beams around the lanterns are almost invisible.

If, on the other hand, you want to make nice long beams around any lantern, then increase the aperture to above f/8. The larger the number, the longer the beams will be.

Illustration that at a low aperture value, there are no “beams” around the burning candles.

The same candles shot at a high aperture value f/21 , resulting in excellent “rays” around them.”

2. Try to have the brightest and closest lights light sources obscured by, for example, a tree, a lamppost, anything. If the light from the flashlight hits the lens directly, you will get a lot of glare.

3. If you use your own light source, like a flashlight, car headlights, etc.., that can NOT illuminate everything at once, then take several shots, illuminating different parts of the object in sequence. If each of the frames obtained is “over-lit”, then when they are added together in one of the programs described above, the object will be illuminated simultaneously in all directions.

4. Do not shoot night and backlit shots when it is windy,.i.e.. Branches and leaves ripple during this time, they will get blurry at slow shutter speeds or when stacking several frames.

On the picture you can clearly see that all the small branches on the birch tree are “blurred” because of the swaying in the wind.

How to shoot a night scene.

1. Choose your subject.
2. Set up your tripod and camera so that the light from lamps nearby does not strike the camera directly.
3. Aim the camera at infinity and fix it in manual mode.
4. Set the ISO to approximately 200 – 400 or higher, depending on what kind of subject you are shooting.
5. set the “Aperture Priority” mode and set it to f/5 to f/8 if you want big beautiful rays, set the aperture to larger than f/8 .
6. Choose one of the three shutter speeds described above, take three frames.
7. Process these frames with one of the programs. Or send the frames to a photo lab of your choice for processing.

The final procedure for taking a backlit shot is pretty much the same. The only difference is that you can take it without a tripod.

A little trick

If you want the sun’s rays to have maximum contrast, do not shoot across them, but along them.

An illustration of hiding in the shade when shooting at night.

Illustration of the appearance of rays in the daytime with a larger aperture value.

Illustration for shooting against the sun at a low aperture value, by connecting three frames.