Sunday, 18 June 2017

Star Eater

Astrophotography - some problems

I have read a lot about the problems with Sony cameras being ` Star Eaters' . I have the original Sony A7s and i gather that there is no problems with exposures up to 30 seconds but if i used bulb mode then the star eater effect would take place

For 99% of the time i would be using less than 30 seconds for my Nightscapes, although i intend to  use my Astrotrac which would allow longer exposures. With a 200 mm telephoto lens i currently can do 3 seconds without star trailing (500 Rule).

Even at 30 seconds would give me a lot better signal to noise ratio with this lens using the Astotrac. I could always change to the Nikon D610 for bulb shots if needed.

I thought about the Sony A7s II but this was not as good at high ISO as the Sony A7s, the upgrade was more for the video side, this is also affected by Star eating above 3.2 seconds due to firmware issues.

Any firmware upgrades cannot be reversed, so i am glad i never up graded mine. The Star Eater problem is down to the software spatial filtering designed to reduce noise in photos

This issue affects all recent Sony alpha mirror less cameras including the a600, a6300, a7s, a7R, a7, a7II, a7sII and a7RII, possibly other models as well. It has been discussed on many forums and individual blogs with many people contacting Sony direct asking for a fix for the firmware.

To test this out take an exposure at 5 seconds then turn to bulb and take another 5 second exposure and compare the two. This one in bulb mode will see stars lacking punch (Brightness) with the star eater effect.

As the nights are too light in Shetland i wont be able to try this out on my camera.

Don't forget to join us on facebook - send a request to join Shetland Aurora Hunter now has over  900 members

Friday, 5 May 2017

Sony A7s incredible ISO range

The Aurora season has finished for us in Shetland, they are still happening but as the nights pull out darkness does not happen until around mid night.

Having used the Sony A7s since January i thought this might be a good time to review its ISO capabilities.

The Sony A7s has an incredible ISO range up to ISO 409,600. Well beyond most cameras and therefore excellent for low light. The Dynamic Range is also superb even at high ISO

For Astrophotography this 12.2 mp camera is ideal, this camera is supported by Lightroom 5.8 my preferred software.

As a result of the low mega pixels and a full frame Exmor sensor the pixels are extremely large and can therefore collect more light. This produces low noise, always a problem with astrophotography as it tests your camera and lenses to the limits.

The images shown are a range of ISO settings, the first in the set exported direct as jpeg's from Lightroom, the second on as a Tiff. Both are converted to web-size.

As you can see the images are clean right up to ISO 51,200 and beyond although Stars tend to get eaten after this although the images are still usable. Let me know what you think. , all these images have been taken on RAW with noise reduction turned off in camera. However noise reduction was undertaken in Lightroom.

I think these are very impressive compared to the Nikon D610 full frame camera which is good up to ISO 3200

I have been very impressed with live view, the milky way looks amazing as you increase the ISO which makes it easier to frame and see what how the final photo will come out. Its tilt screen is another bonus as you point the camera high up.

Where the Sony A7s excels as a tool for astrophotographers is its live view feed, particularly with its S-log2 picture profile PP7 enabled (available via Menu>camera>5 Picture Profile.

I need to carry out more tests but so far i am impressed, just have to wait now until late September when it come dark.

Don't forget to join Shetland Aurora Hunter on facebook - send a request to join already over 870 members

Monday, 17 April 2017

Full Moon at Bigton

It was just after a full moon at Bigton when we made the short visit over the hill. An Aurora was showing but very faint in the moonlight.

Even though it was supposed to be a clear night cloud built up quickly

Looking south cloud quickly obscured the night sky

Only a short visit but still worth getting out under the Shetland night sky

Facebook - Shetland Aurora Hunter send a request to join

Monday, 27 March 2017

22 3 17 Tingwall Aurora

Although not as active as the night before it was still a good  Aurora show under a clear sky at Tingwall

Using the car headlights to light up various parts of the landscape is a good idea to add an extra dimension to the photo

The reflection in the loch from the stars and colour of the Aurora also gives depth

On a previous post on Tingwall, lots of cloud was present reflecting the Light pollution from Scalloway and Lerwick but on this occasion with clear skies the south gave a more natural colour

Did you observe Earth Hour on Saturday 8.30 - 9.30 ?

Using car head and tail lights adds a bit of a focal point

Looking north to the old Manse is one of the classic views in Shetland.

I will be offering a new 6 session course on Nightscape Photography for Shetland Adult Education around October 2017 (in Shetland) message me if interested

If you haven't does so, please send a request to join the facebook page - Shetland Aurora Hunter. Lots of great photos and interesting information

Thursday, 23 March 2017

Superb Aurora 21 3 17

The 21 3 17 proved to be one of the best Aurora's we have seen coming to Shetland. First a clear night, that's been a rarity recently and the prospect of a good Aurora tempted us to visit Bigton.

A rare sight in the UK, a pink Aurora (For a short time)

The colours on the night were amazing, anything from various shades of green, purple, pink, even a bit of blue

From the off the Aurora was very active with pulsating pillars and lighter green curtains moving rapidly across the sky

reaching above the green curtains large purple pillars all moving very fast. All these captured at 1- 2 seconds at ISO 6400

I left after 2 hours after it seem to be calming down as it reached 11 pm, but this one will stay in our memories for many years to come. March has proved to be a good month to see Aurora's

More photos to come once i have had time to process them

Join us on Shetland Aurora Hunter facebook page - send me a request

Sunday, 19 March 2017

Tingwall Light Pollution

Tingwall can be very good for seeing the Aurora but it also suffers from light pollution, which is especially evident when cloud forms

The first two are looking north and east showing light pollution from Lerwick

The 4 photos below are looking south picking up light pollution from Scalloway

You can still see Orion from half way up Tingwall valley

Further north at Brae and Sullom the light pollution is very bad.

Join us on Shetland Aurora Hunter - send me a request, here you can see many more photos of the Shetland night sky from a number of people