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Showing posts with label Night Safari. Show all posts
Showing posts with label Night Safari. Show all posts
11 Nov 2013
De-noise Using DxO Optics Pro 9

Yesterday's article on 'Challenging Photography at Night Safari', I posted a number of photographs that were taken in high ISO (i.e. ISO 25600). Honestly, this is the very first time where I had taken pictures at such high ISO and it gives me the opportunity to look into how to reduce the high noise produced at such high ISO.
Picture taken with ISO 25600, de-noised using DxO Optics Pro 9 (PRIME).

What is Image Noise?

Grainy-looking color splotches in photographs are known as noise (see picture below). Noise could either be a color noise or luminance noise (or both). Color noise shows up as colored pixels (e.g. red and green pixels) in the photographs, while luminance noise is prevalent in the brightness of a color (i.e. grains across a color).
A 100% cropped of a section from the 1st picture above, showing the amount of noise taken at ISO 25600 using Canon EOS 5D Mark II.

What Causes Image Noise?

Noise are produced in photographs which is caused by:
  • High ISO
  • Long exposure time
  • Small sensor size - small sensor size like phone cameras will produce grainier pictures as compared to DSLR sensor.
  • High ratio of pixel density to sensor size - A 20 megapixel on a small sensor will produce more noise compared to 20 megapixel on a larger sensor.
  • Shadows or poorly illuminated areas

How can Noise Be Reduced?

Besides from observing the above conditions that could result in noise when taking photographs, there are also other imaging softwares that could help to reduce noise during post-processing. I uses Apple's Aperture 3 in my processing workflow and rely on the adjustments (including de-noise) for 90% of my photographs, while the remaining 10% uses Photoshop for additional creativity work.

It is important to understand that when an image is de-noised, certain amount of details may be lost and the photograph may appear to be 'softer' (or losing some amount of sharpness) depending on the software used.

De-noise Comparison between Aperture 3, Nil Dfine 2 and DxO Optics Pro 9

For de-noise, Aperture 3 typically does a great work for most of my photographs since they are usually taken within an acceptable ISO level (up to 3200).

In these particular set of photographs taken at Singapore Night Safari using ISO 25600, I had compared the de-noise capability of Aperture 3, Nik Dfine 2 as well as the new DxO Optics Pro 9 which has introduced PRIME, a technology a revolutionary noise reduction which claim to be able to re-produce detailed, sharp and vividly-colored images.

Note: This is the first time using DxO Optics Pro 9, which I had downloaded the full-functional one-month try copy from DxO Mark. The adjustment are based on some of the preset functions offered in the software.

For comparison purposes, I've cropped out 50% of the full-size image above. Please click on the image to view the higher resolution image.

RAW Files Without Post-Processing

As seen from the RAW photographs below, the amount of noise taken at ISO 25600 is extremely high without any post-processing.


De-noise using Aperture 3

Aperture 3 does a fairly good job in removing most of the noise in the picture and yet retain most of the details. However, the picture appears to be a little 'soft' and unsharp due to the de-noising.


De-noise using Nik Dfine 2

There appears to be color splotches of noise despite pushing the color and contrast noise control to the extreme. Just like aperture 3, the photograph appear to be 'soft' and a little un-sharp due to the de-noising.


De-noise using DxO Optics Pro 9 (Standard)

DxO Optics Pro 9 offers standard de-noising function as well as the PRIME de-noising technology. The standard de-noising function does a very good job in removing the noise. The processed photograph is not as soft as compared with Aperture 3 and Nik's Dfine 2. There is also noticeable enhancement to the colors.


De-noise using DxO Optics Pro 9 (PRIME)

The PRIME de-noising function is remarkable. Very noticeable that the details and sharpness were retained. Not only that, the colors are also enhanced. I also noticed that some barrel distortion on the picture has also been corrected.

Conclusion

Picture speaks a thousand words - from the comparison, it is quite obvious that the DxO Optics Pro 9 produces remarkable results using its PRIME de-noising technology. However, it takes about 9-10 minutes processing time to output a single photograph of resolution 5616 x 3744 on my iMac (2.8GHz Intel iCore i5 with 8GB memory) which can be a major concern if processing hundreds of pictures.

Once again, the level of acceptable noise is very subjective to individuals. For me, I would still rely on Aperture 3 as my key workflow processing tool. Although I'm still using the free one-month trial of DxO Optics Pro 9, I may consider purchasing a licensed copy as it would give me the piece of mind without hesitation to bump the ISO, or recover a badly under-exposed photograph.

Note: DxO Optics Pro 9 is on an introductory offer till 20-Nov-2013. The standard edition costs 99 USD (instead of 169 USD), while the elite edition costs 199 USD (instead of 299 USD). Check it out at http://www.dxomark.com/.

Another picture taken with ISO 25600, de-noised using DxO Optics Pro 9 (PRIME).

 Please visit http://jefzlim.smugmug.com/Destinations/Singapore/Night-Safari to see the entire bunch of photographs taken at Singapore Night Safari using ISO 25600 and de-noised using DxO Optics Pro 9 (PRIME).


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10 Nov 2013
Challenging Photography at Night Safari

  • at 10:44 pm
  • 0 comments
I love photographing wild life at the zoo, and the thought of photographing nocturnal wild life at Night Safari excites me. On Friday, I visited the Singapore Night Safari - the entire experience was really great where I can get really close to these nocturnal wild life during the tram ride and walking trails. However, photographing them has been a great challenge.
Picture taken at F/2.8, ISO 25600 and 1/8s (0 EV) using EOS 5D Mark II.

Key Challenges: Very Low Lighting Without Flash Photography

Many of us are used to taking photographs under a lighted environment, and even if lighting conditions is not ideal, we would pull out our flashes. 

At Night Safari, the lighting condition is far less than sufficient, which is obviously the case as the ambient lighting needs to fit the night environment for these nocturnal creatures. In addition, flash is prohibited as the bright light from the flashes may blind these nocturnal wild life.

Exactly how low or bad is the lighting condition? Just imagine with the widest aperture (F/2.8) used on ISO 25600, the camera would meter shutter speed in Aperture Priority (AP) mode to be within the range of 1/6 seconds to 1/30 seconds in most of the scenes.

Perhaps the consoling part is that these nocturnal creatures are pretty still or moving fairly slowly, which does not make it worse for the low shutter speed.
Picture taken at F/2.8, ISO 25600 and 1/25s (0 EV) using EOS 5D Mark II.

Techniques to Take Better Pictures Under Very Low Light Condition Without Flashes

Fast Lenses with Widest Aperture

Go for the lens that can give the widest aperture (i.e. smallest F-number) - will need all the lights that can get onto the sensor, hopefully without need to compensate too much on ISO and shutter speed.

Step-Up ISO

With the aperture wide-open, start stepping up the ISO until a sufficient shutter speed can be metered by the camera. If the "normal" ISO range could not get you the right exposure, then ISO expansion may need to be enabled from your camera's menu so that an extended range of ISO can be used. High ISO will produce a lot of noise in the photographs taken.

Note: High ISO will produce a lot of noise in the photographs taken. So, you may want to enable high ISO noise reduction from your camera's menu if using high ISO.
Picture taken at F/2.8, ISO 25600 and 1/10s (0 EV) using EOS 5D Mark II.

Exposure Compensation (EV)

If the speed is deemed to be still too low to hand-hold the camera, set the exposure compensation down a stop if using Aperture Priority (AP) mode. Doing so will increase the shutter speed a little. The exposure can be compensated back during the post-processing.
Picture taken at F/2.8, ISO 25600 and 1/30s (-1 EV) using EOS 5D Mark II.

Use Tripod/Monopod

If the shutter speed is relatively low and you do not have a good steady hand for hand-holding the camera, then using a tripod will help to prevent shakes which will result in a blur photograph taken. I've taken all Night Safari on hand-held - if I can do it, so can you :)

Anyway, a good way to gauge whether the shutter speed is fast enough to 'ignore' any slight mini movement is to check that the shutter speed is faster than the inverse focal length used i.e. if focal length is 200mm, any shutter speed lower than 1/200 seconds has higher chances to pick up any slight mini movement caused due to hand-holding the camera or mirror flipping action when camera shutter opens. 
Picture taken at F/2.8, ISO 25600 and 1/60s (-1 EV) using EOS 5D Mark II.

Manual Focusing May Still Be a Problem

In most of the scenes, I find that the camera was unable to automatically focus on the subject due to the extremely low light condition and I had to switch to manual focus. However, I still find that manual focusing can still be very difficult to my eyes in the dark.

If you ever run into the same problem, you may want to try out the following technique by using the AF-assist beam firing from the Flash (note: without firing off the flash).
  • Attach and turn ON the flash on the camera. 
  • Access the camera menu and ensure that the 'AF-assist Beam Firing' is turned ON. This will enable the flash to 'fire' some red light whenever the trigger is half-pressed.
  • Since flash is not allowed, the 'Flash-Firing' option in the camera menu needs to be turned OFF. This is very important, if not the flash will just go off and you will have the park attendants coming after you. 
  • Switch the lens focusing mode back to auto-focus mode. Now, just half-press the shutter button and the Flash will 'fire' off some red low light which will help the camera to focus on the subject. 
Picture taken at F/2, ISO 12800 and 1/30s (0 EV) using EOS 500D.

Shoot In RAW

High noise, exposure compensation, etc ... these are strong reasons why you should be shooting in RAW so as to maximize the need for adjustments to the taken photographs during post-processing.

Other Things to Note

  • Go for the 'Live Show' - lighting conditions are way much better (see picture below). You may want to note that the 'Live Show' is only available on Friday, Saturday and Public Holidays.
  • Park attendants are all over the place, and you will have no chance to use flash. They will chase after you if you do so :) Please do not use flash to protect these nocturnal wild life.
  • It is almost close to impossible to take good pictures during a tram ride (i.e. low light, slow shutter speed and moving). You can try but best thing is to sit back and enjoy the ride experience.
  • There is strong 'dung stench' at certain part of the tram ride, and the women behind me simply throw up. Bring mask or medicated oil if you cannot take strong stench :)
Picture taken at F/2.8, ISO 25600 and 1/400s (0 EV) using EOS 5D Mark II.




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