Skip to main content

Pushing to +5EV, Pentax K1 & PetaPixel

I have been working hard on the Sensor DB, add new features and models. As part of the process of adding newer and better models I have re-processed all of the samples to +2.5EV and +5EV. This allows the noise to be more visible in the samples for comparison. It was getting tougher to determine visually how samples were comparing. With this problem in mind I also added some statistical data to show the RGB noise characteristics and the mean, median and standard deviation are now shown.

New models added include bodies from Fuji, Nikon, Sony, and Pentax, including the new K1, along with the Fuji XPro2. I’m also hoping to add new search features soon to allow searching by sensor size. This will make it easer to compare common models.

I’d also like to thank Michael Zhang at PetaPixel for the great review of the Sensor Database on their site. Thanks for the write up, I’ve had a lot of positive feedback, and it certainly seems to have caused a lively debate.

 

Playing with the light. ND Filters.

Most good modern DSLR’s have a good amount of Dynamic Range (DR), DR is the measurement from the brightest to the darkest a sensor can capture in one image, beyond this range highlights will be blown and dark shadows will yield no detail. It is normally measured in Exposue Values (EV). A Good sensor will be at least 12, and maybe as high as 16.

But what do you do if the image you are trying to capture has more DR than my sensor can capture? Well there are a number of ways to deal with this, these are the most common:

  • Take multiple exposures to combine into one image, either as a composite merge or a high dynamic range shot (HDR), later models can do HDR in camera.
  • Add additional light to the scene.
  • Use filtering effects to modify the light being exposed.

BPD_1948HDR and adding light are fairly common, but using filters is not very common for night sky photography and Aurora’s. The reason it is not popular is that adding filters reduces the amount of light entering the camera, resulting in either having to use higher ISO settings or longer exposures.

However given the right circumstances using a filter can have great results. I like to use them for shooting Aurora’s provided the Aurora is very bright and it has minimal movement. If the Aurora is bright I don’t need to increase my ISO, and minimal movement like beams in the Aurora will mean I can increase the exposure time a little without blurring any details.

I have found that using a 0.9 (3 stop filter) helps significantly with exposure compensation, balancing out the light Aurora in the sky to darker foregrounds. Not only does it help with the balance and bringing out blacks, but it effectively gives your sensor a 3 stop advantage.

A sensor that can shoot 14 stops of DR is suddenly equivalent to 17.

Suddenly I’m no longer dealing with those horrible black dark areas where the noise hides.

The Tessellated Pavement, Tasmania

IMG_8241It’s taken me a while but last night the weather was favorable and I managed to finally get a reasonable Aurora over the ‘Pans’ at Eaglehawk neck. As an added bonus I also scored a little airglow as well, seen here as the green glow to the left of the picture 🙂

For these shots I used an ND Grad filter to darken the sky allowing more exposure in the foreground without overexposing the glow of the Aurora.

“The most well known example of a tessellated pavement is the Tessellated Pavement that is found at Lufra, Eaglehawk Neck on the Tasman Peninsula of Tasmania. This tessellated pavement consists of a marine platform on the shore of Pirates Bay, Tasmania. This example consists of two types of formations: a pan formation and a loaf formation.

IMG_8229The pan formation is a series of concave depressions in the rock that typically forms beyond the edge of the seashore. This part of the pavement dries out more at low tide than the portion abutting the seashore, allowing salt crystals to develop further; the surface of the “pans” therefore erodes more quickly than the joints, resulting in increasing concavity.

The loaf formations occur on the parts of the pavement closer to the seashore, which are immersed in water for longer periods of time. These parts of the pavement do not dry out so much, reducing the level of salt crystallization. Water, carrying abrasive sand, is typically channeled through the joints, causing them to erode faster than the rest of the pavement, leaving loaf-like structures protruding.”

-WikiPedia.

Reviewing the D810 and D610 Sensors.

Hi All,_MG_6790

So the new Nikon D750 is awesome right? But there seems to be some very conflicting information available on the internet.

Nikon have claimed that the new sensor in the D750 performs much better than the existing technology currently being used in the D8X0 and D6X0 cameras, particularly when it comes to low light and noise performance.

However Dx0’s testing revealed that the D750’s sensor is only just on par with the D610 and offers little advantage based on their testing.

So how do the D610 and the D810 compare to the new D750 for long exposures?

Well the data is in, head on over to the Long Exposure Sensor Test page for the results. Thanks again to Walch Optics for allowing me to run the tests.

Oblivious to the lights.

IMG_7875When your out shooting late at night you have a lot of time for thinking during exposures and between shots, especially if your by yourself. I often think of all those people at home, watching TV, or asleep in their beds, oblivious to what is going on around then, and the silent lights that weave across the night sky above them.

I think the mood in this shot sums up how I often think of those people. They are inside, working away or watching some program on TV. Meanwhile outside the lights are dancing in the sky and the stars are shining brightly on a perfectly clear and moonless night.

The picture was taken in Mortimer Bay (Tasmania). The photograph to the right was taken only a stones throw from the boat shed when the Aurora was a little more active.

Aurora Australis – Storm.

South Arm Beach by Brendan Davey
South Arm Beach, a photo by Brendan Davey on Flickr.

Tasmania, and Southern Victoria witnessed a fantastic Aurora last night and I managed to shot quite a number of great shots.

The Aurora was quite visible with the naked eye, and it was very easy to see the ribbons, and at one stage they were so bright they were showing clearly in live view on my camera. WOW.

Hopefully we will continue to see more over the coming months.