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Showing posts from February, 2018

Astrophotography lessons

Keen to test the information learnt from my recent ISO Invariance article, I stopped at Rottingdean windmill on the way home from camera club a few evenings back. The temperature has been falling for the last couple of weeks, and last Thursday in particular was rather cold in the evening. When I left the club to drive home, the sky was clear of clouds, adding further to the lower temperatures. I arrived at the windmill, which is situated in a field north of the coast road - if you go any further south, your feet would get wet! Walking up the hill, the chill began to deepen as the wind picked up. Yes, who'd have thought a windmill would be built somewhere with wind? Picture info: Lumix GH4, Voigtländer f/0.95 17.5 mm, ISO1600, f/1.2, 15 sec Anyway, I planted my tripod and set up the shot. The plan was to get the windmill in the lower third, and use the rest of the frame for a sky full of stars. As I adjusted the tripod, clouds began to quickly arrive from the north. I ma

The Bluebell Conundrum

A couple of years ago, I was on the hunt for bluebells to photograph. Native bluebells, not the invasive Spanish species which are threatening British woodland. Although the Olympus f/1.8 45mm was very good for getting a nice blurred background, the close-focus distance of the lens was a disappointment. In addition, shooting wide-open usually meant focusing issues: either mis-focus or not enough of the subject in focus. Picture info: Lumix GH4, Olympus f/1.8 45mm, ISO200, f/1.8, 1/1600 sec I soon found that the Lumix 14-140mm Mk2 at 140mm was very good for these types of shot. A minimum aperture of f/5.6 means that you're getting a large chunk of the plant in-focus, and the extra focal-length usually produces a relatively pleasing bokeh despite the slow-aperture and zoom. Picture info: Lumix GH4, Lumix G VARIO 14-140mm @ 130mm, ISO800, f/5.6, 1/200 sec The travel-zoom has effective in-lens stabilisation, yet despite this it can still be tricky to get sharp hand-held

ISO Invariance

Way back in March 2017, Petapixel had a fascinating article on ISO invariance in digital camera sensors. The article details how ISO affects exposure, and how to ascertain the best ISO for low-light work - in particular, for astrophotography. For one of their tests, a Sony A7S was used (Canon 700D and Fuji XT1 for others), and I doubt you can get a better stills low-light performer than that! Reading the article got me thinking - how would my Micro Four Thirds camera function in a similar test? Bare in mind the Four Thirds sensor is half the size of the full-frame used in the A7S, and 16 megapixels versus 12.2 megapixels in the Sony. So while the sensor is small, the pixel-count is higher, meaning the photosites are smaller in the m43 camera as well. Anyway, I'm getting into too much detail in the technical comparisons! Let's look at how we test ISO invariance. Take a series of shots in RAW, each at whole-stop ISO and  match the exposure brightness in post across the range

The scores are in... "Liquid" set subject print competition

Thursday just gone was competition night at the club, the set subject print competition for " liquid ". The judge, Ken Wood LRPS, was introduced, and a comment was made that his Flickr page showed a lot of close-up and black and white shots. Which instantly had me thinking I was in with a chance for some good scores for my submitted prints. Camera club judges are always a difficult bunch to please. Some will be very strict on what they want to see in a subject competition, and in this case Ken was very specific - he wanted to see motion, he wanted to get a fluidic feel from the image, and it had to be the main subject of the composition. If a photograph didn't have any of the above, then it received a poor score. The club's scores are out of 20, though images rarely get less than 15. I think the lowest score I've seen is a 12 (which tells me that the range should be reduced to something like 10), but an average score is 17, with anything above classed as very

"Liquid"

For a while now, I've been thinking of images I could submit for the next camera club set subject print competition - "liquid" is the theme, and entries due in tomorrow. Going through my LR catalogue metadata, I found plenty of shots of the sea - well, I do live right next to the English Channel! But this seems like a bit of a cop-out for the theme, and particularly if the sea itself is only part of the subject, as it would be in a landscape. A stroke of luck presented itself one evening after work, when I glanced out of the kitchen and saw a single iris had bloomed in the rockery outside the back door. It had been drizzling most of the day, and a delicate pattern of droplets had formed on the petals. However, I wasn't able to get outside to shoot it until much later in the evening, by which point the sun had long since set. Which meant a tripod, a flash, and my Raynox 150 macro adapter on the end of the Lumix 14-140 Mk2. A variety of compositions, apertures a