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Last Saturday, I was photographing along the California Hwy 1 coastline at night. It was pretty dark requiring long exposures. With that came a noise problem – a red streak in the image. See below.

Long Exposure Night Shot of Sea Stack showing red streak noise

Long Exposure Night Shot of Sea Stack along California Hwy 1 Coast. See the two red streaks in the lower one-thirds of the image.

This was an eight minute exposure. Shot at f22, ISO100. Nikkor 70-200mm f2.8 lens and Nikon D4S body. Fortunately, I had another two minute exposure of the same composition, made when there was a bit more light that would work for me as a keeper. So, I had not lost the shot. But, it was disconcerting to realize that I was limited to two minute exposures with this lens for night shots.

First, I wanted to ascertain that the red streak noise was repeatable. I ran a series of tests on long night exposures yesterday, only to realize that with this lens, it was very repeatable as long as the scene was pretty dark and my exposure was greater than 2 minutes @ ISO100. I also verified other ISOs and found that the red streak noise found during 4 minutes @ ISO100 and that found during 1 minute @ ISO400 were about the same. There was no escaping this. If I needed to shoot in very dark conditions – I will not be able to get away with shorter exposures, using ISO to compensate. This was depressing …

Next, I attempted to see if “long exposure noise reduction” would compensate for this issue. After all, the long exposure noise reduction works by making a dark exposure with identical parameters, with the shutter closed. The idea is that the noise on the sensor would be same, which is later subtracted from the main image, thus reducing or eliminating to a great extent the noise resulting from long exposure. The results of these tests were disappointing as well. The noise was the same in the RAW files, but slightly reduced in the in-camera JPGs. I shoot 100% RAW and would not be happy switching to JPG for the slight reduction in the red streak noise. I needed to solve it fully.

As I drove around and lived my life today, it occurred to me that I should perhaps try to apply the long exposure noise reduction idea manually. At the next opportunity I got, I put the lens cap on the same lens and made an eight minute exposure at f22 and ISO100. The resulting dark exposure with red streak noise is shown below.

Dark exposure with lens cap on, recreating the red streak noise alone.

Now, I had to figure out a way to subtract the red streak noise seen in this image, from the original image. Since I have been stacking images in Photoshop for years, this was easy for me to figure out. Here is the procedure:

1. Load both images from LR into PS as layers.

2. Right-click the layers in PS and “Convert to Smart Object”.

3. Pull-down “Layer” > “Smart Objects” > “Stack Mode” > Range.

Stacking using “Range” makes sense, because it is essentially subtracting the maximum signal from the minimum signal and providing the difference. Since the second image (containing only the red streak noise) has black in the rest of the image, only the red streak noise will get eliminated.

I tried this procedure and “bingo”, it worked. The red streak noise was eliminated and there was no loss to the image quality. All details of the underlying image came alive just as I had imagined. The resulting red streak noise free image is shown below.

Red streak noise has now been eliminated in this image, using the procedure mentioned in this post.

Conclusion – While I have not solved how to prevent the red streak noise in the first place, I have a pretty good procedure to deal with it in post. Just take another image with the same exposure parameters as the real image, with the lens cap “on” this time. This may be done several days later and in conditions different from the shoot. Then, subtract the latter from the former using the PS procedure just outlined.

PS. I have observed this red streak noise in my Nikkor 70-200mm f2.8 VR lens. Others have reported it on the Nikkor 16-35mm f4 lens. I checked my 16-35mm f4 lens and do not see this noise in that one.

If you have seen this type of red streak noise during long night exposures, please try this procedure and let me know if it worked for you. I would appreciate it, if you could post your success story as a comment here. Thank you for your attention.

Photography is commonly thought of the way to make an image of something seen by the eyes. This is commonly true, of course. However, photography is also capable of capturing images, not exactly visible to the eye. In this post, I shall talk about six of them. I call this post “6 Ways To Photograph The Invisible”. By “invisible”, I mean that which cannot be seen exactly as depicted in the photograph. Let’s begin.

1. ADJUSTING FOCAL LENGTH DURING A SLOW EXPOSURE

Consider this image I made at an apparel store, when my family was trying on clothes.

Apparel in Mall

This image was created by using a slow shutter speed and zooming in (changing the focal length), during the exposure. The metadata for this image is the following: Nikon D300, Nikkor 17-35mm f2.8 lens, Aperture Priority, ISO 200, f10, 1/5 s, Hand-held, zooming the focal length constantly during the exposure.

While this photograph is interesting (at least to me), can you really see something like this with your eyes? Therefore, I consider this to be the first way to photograph the invisible.

2. MOVING THE CAMERA DURING A SLOW EXPOSURE

Now, consider this image.

Road seen from a moving car

To make this photograph, I was sitting comfortably and legally in the passenger seat of a moving car, while a good friend drove the car. The tripod was setup inside the car with the tripod/ball-head sticking out from the sunroof. An electronic shutter release cable reached me comfortably. Before starting the drive, I positioned the camera to look straight ahead, composing carefully to avoid the hood of the car, while at the same time pointing downwards, just enough to achieve the right balance between the ground, horizon and the sky. After the drive began, I clicked over a thousand shots in that drive, to find a few keepers eventually. The metadata for this shot is as follows: Nikon D300, Nikkor 18-55mm f3.5-5.6 lens, ISO 200, Aperture Priority, f25, 1/8 s, Gitzo 1340 Tripod, Kirk BH-1 Ballhead, Nikon electronic shutter release cable.

Such a scene is never visible to our naked eyes and therefore, I consider this to be my second way to photograph the invisible.

3. ALLOWING THE SUBJECT TO MOVE DURING A SLOW EXPOSURE

Consider this image of an Anise Swallowtail Butterfly.

Anise Swallowtail Butterfly

I shot using my telephoto lens and adjusted the shutter speed to be slow enough to allow the movement of the wings to be captured. The metadata for this image is as follows: Nikon D300, Nikkor 70-200mm f2.8 lens, Nikon 2x Teleconverter, 400mm, ISO 200, Aperture Priority, f11, 1/80 s, Gitzo 1340 Tripod, Kirk BH-1 Ball-head. In this case, it is also important to note that although the wings are not sharp indicating a sense of movement, the eyes are still sharp. An entirely blurred butterfly will not cut it. The sharp eyes allow you to connect with it, while the blurry wings indicate motion.

Since our eyes and memory do not have the ability to retain the past and combine it with the present, visually, one cannot see what this image has captured. To me, this is the third way of photographing the invisible.

4. USING VERY HIGH SHUTTER SPEED DURING FAST ACTION

While we have so far seen how a slow shutter speed creates images not usually seen by the naked eye, a very high shutter speed can create equally interesting images that our eyes cannot see.

Take for example, this image of a snowy egret splashing water to catch its prey. The high shutter speed has frozen the water in air.

Snowy Egret and frozen splash

The metadata for this image is as follows: Nikon D300, Nikkor 70-200mm f2.8 lens, Nikon 2x teleconverter, ISO 200, Aperture Priority, f5.6, 1/800 s, Gitzo 1340 Tripod, Kirk BH-1 Ball-head.

Our eyes are incapable of freezing visual information that happened in a very short span of time such as 1/800 s. Therefore, this is my fourth way of photographing the invisible.

Here is another image of a boy splashing water in the pool. This cannot be seen by the human eye and yet can be captured by the camera.

Boy splashing water in pool

The metadata for this image is as follows: Nikon D300, Nikkor 50mm f1.4 lens, Aperture Priority, ISO 200, f5.6, 1/160 s, Hand-held.

5. LONG EXPOSURE OF TRAFFIC TRAIL LIGHTS AT NIGHT

Traffic trail lights at night is quintessential image-making demonstrating the capture of that which cannot be seen. Consider this Las Vegas Image. The long exposure enables capture of the bright traffic lights (without exposing for the significantly darker vehicles themselves).

Las Vegas at Night

The metadata for this image is: Nikon D300, Nikkor 17-35mm f2.8 lens, ISO 200, Aperture priority, f22, 14 s, Gitzo 1340 Tripod, Kirk BH-1 Ball-head, Nikon electronic shutter release cable (several exposures stacked together in Photoshop).

This is my fifth way to photograph the invisible.

Yet another traffic trail image of a local street near my home in San Jose, CA.

Traffic trails at night, San Jose, CA

The metadata for this image is as follows: Nikon D300, Nikkor 70-200mm f2.8 lens, Aperture Priority, ISO 200, f16, 15 s, Gitzo 1340 Tripod, Kirk BH-1 Ball-head, Nikon electronic shutter release cable (several exposures stacked together in Photoshop).

6. FINE APERTURE EXPOSURE OF NIGHT LIGHTS

Consider this image of Austin Downtown at Night.

Austin Downtown at Night

The most prominent foreground of this image is the star pattern from the nearest street light. Can you see a star pattern when you look at street lights with your naked eye? Of course, not. This is simply an optical phenomenon manifested in lenses. If your aperture is f22, point light sources convert themselves into stars. No, a star filter is not essential to get this effect (I have never used a star filter). The metadata for this image is as follows: Nikon D300, Nikkor 17-35mm f2.8 lens, Manual exposure mode, f22, Several exposures (1s, 2s, 4s, 8s, 15s, 30s, 1min, 2 min) composited using the HDR technique, Gitzo 1340 Tripod, Kirk BH-1 Ball-head, Nikon electronic shutter release cable.

This is my sixth way to photograph the invisible.

ABOUT ME – Hello, I am Satish Menon, founder of http://pixgaga.com. Visit my website to learn more about me, see my image gallery or to listen to my student testimonials.

MY REQUEST TO YOU – If you have enjoyed reading this post and if this has perhaps triggered an expansion of your photographic vision, please forward this post to a photographer friend. Also, if you practice other ways in which you photograph the invisible, please reply and share it here. Lastly, if you are interested to receive digital photography tips from me on a regular basis, register at my website at: http://www.pixgaga.com/users/new. I do conduct digital photography webinars (free), seminars and workshops, announced exclusively to my mailing list.

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Tag Archives: exposure

Red Streak Noise in Long Exposure Night Shots Solved

6 Ways To Photograph The Invisible