Foveon Sensor Fun

Ian collects guitars. I seem to collect cameras. I’m playing with a second hand Sigma DP2s that I picked up as a kind of birthday present to myself. This is a neat looking compact that uses a Foveon sensor. This sensor works in a different way to the ones in most cameras which use a “Bayer” design. With this each sensor is covered by a coloured filter that lets the sensor read only that colour. So to get the colour of a particular pixel you need three sensors, for Red, Green and Blue. Actually most cameras use two Green sensors, since that is colour that has the greatest effect on brightness as far as the human eye is concerned.  So that makes four sensors in total.

But anyhoo, this means that to get the colour of a pixel the camera must read the brightness of a bunch of pixels and then combine them using some clever maths. Then the camera does something even cleverer and works out the colour it would be at each of the Red, Green and Blue positions, based on the readings from those around it. This is a bit sneaky, in that it means that your 16 megapixel camera isn’t actually reading 16 million coloured dots. It is actually working a lot fewer colour values and then spreading these back over 16 million points. This can lead to pictuers with artefacts (funny shapes that appear as a result of the averaging process) and noise (because the maths is really only a form of guessing).

The Foveon sensor doesn’t do any of this. It uses a cunning silicon sensor that reads all the colour values at each pixel position. The bad news with a Foveon sensor is that it doesn’t have quite many pixels as most “Bayer” designs, so the ultimate resolution is a bit lower than what you get from other cameras. However, all the dots are “real” dots, and I think this counts for quite a lot in terms of picture quality, as you can see above.

If you want a camera that is quite a challenge to use (the sensor and lenses on the Sigma camera are very good but the electronics and user interface are a bit of a pain when compared to more popular offerings) then you should take a look at the DP1 and DP2 devices. They are also a good way to learn how photography really works, in that to get the best from them you have to take things like exposure and focus very seriously.

You can pick them up second hand from ebay at reasonable prices, and they are great fun to use.

Hull University in 3D

I’ve been playing around with a 3D camera and I think it sort of works. these are the left and right pairs that I took on the way into the office. I’ve found this really useful program that can convert the stereo MPO files produced by the camera into twin jpegs. If you want to see exactly what I saw as I walked past the library you just need to print these out and stick them on the inside of your 3D glasses. 

Lord Mayor’s Parade

Today was the day of the Lord Mayor’s Parade through Hull. I was in town at the time, and had the little camera with me. Unfortunately I also had a enormous suitcase that I’d just bought, which made moving around the crowd a little tricky, but I did manage to take a few shots of the fun and festivities.

This is as the procession went past. Note that there are some people in this picture who are even taller than me.

Only a really skilled photographer can manage to get a traffic light to grow out of the Lord Mayor’s head…

May Day Bank Holiday Happiness

Rob’s recipe for May Day Bank Holiday Happiness

1. Drive to Whitby.
2. Enter “The Magpie Cafe”
3. Order “Magpie Fish Pie” and a pot of tea
4. Eat and drink same
5. Go for walk on pier and beach
6. Take loads of pictures

Oh, and stop off in Bainton at the Wolds Village for a cream tea on the way back.

Dalby and Ducks

Went to Dalby Forest today. (having a tiny holiday) Great place. Once we arrived we had a coffee at the Purple Mountain Cafe. If you like riding bikes at great speed down steep hills you should go there. They arrange all kinds of races and stuff (including truly scary sounding 12 hour ones). Find out more here:

http://www.purplemountain.co.uk/

“Excuse me, can you hire these bikes?”
"Certainly sir, they have a small adjustment at the back”

Note – this joke completely breaks if you write it down….

Then we went for a walk around, and I took the big camera.

Look! Blue Sky!

We rounded off the trip with a visit to Thornton-Le-Dale, which has a lake and ducks.

Nobody mention oranges.

Scarborough Fair

Scarborough Castle

Went to Scarborough today. Good weather, good food, great pinball machine.

Name the TV show…

Bronte Country

The six Bronte children had a pretty raw deal in many respects.  Their father, Patrick, lived long enough to see every one of them die, along with his wife and, from the look of the church graveyard, loads of the local population.  Haworth in the nineteenth century was a world apart from the neat town it is now, with squalor and disease running rampant.

The three Bronte sisters grew up watching loved ones die around them, starting with their mother and two sisters. That they chose to escape into a made up world of stories is not terribly surprising. When they grew up they took this story telling into the wider world and produced a collection of books that was like nothing before.

I’m not a great fan of their writing, but I do like going to the Parsonage in Haworth where they grew up and wrote their greatest works. There are only a handful  of  rooms in the small building, but actually being in the room where Charlotte wrote “Reader, I married him” is pretty darned cool, although I did rather spoil things for number one wife when we were in the shop on the way out and I pointed at a row of paperbacks saying, in tone hushed with awe, “Hey, they wrote books as well!”.

I also insisted on buying a genuine Bronte Parsonage combination spirit level, torch and screwdriver tool. Apparently Emily used to use one just like it it to change the batteries in her digital watch.  Or something.

Getting to Haworth was made much more interesting by the unexpected arrival of a large amount of snow overnight. This made driving great fun and meant the first thing we had to do in Haworth was find somewhere that sold wellington boots.  On the other hand, it did make the pictures nice. And I was lucky to see a steam train arrive at Haworth station. (although of course you know that Haworth was not actually connected to the railway network until some time after the death of the sisters, who had to travel to the station at Keighley when they wanted to go to London to meet their publisher).

Of course I took a camera, and a bunch of pictures.

Genuine bona-fide steam train

Platform

Haworth rooftops

Fairly quiet for a Saturday..

Haworth graveyard

Train home

Cheese Clipart

You wouldn’t believe how much pictures cost for games. I can get a picture of a piece of cheese for a pound I can use in a web page. If I want to put it into a game I’m going to have to spend an awful lot more than that. More than the price of a piece of cheese…..

So today I was in the conservatory photographing cheese for use in my next cheese based XNA game project.  And next I’m going to eat it all.

Rob Miles–Tastes Like Chicken

Thanks for that Christophe…..

Cheap Ring Light

Some time ago I bought a ring light for my camera. This puts a bunch of super bright LEDs around the lens for illumination with no shadows. Works very well and wasn’t that expensive.  It is great for taking pictures of small items. I’ve just discovered that you can get something very similar for well under a fiver.

The Wilko Multi-purpose LED light is actually a very good light. We are going to use one to light up our summerhouse in these dark winter nights. However, it also has a hole in the middle where you can put a small camera lens, and so it also makes a rather good ring light. At less than a fiver it is well worth a look.

Worth tracking down, whether you are after lighting up underneath the stairs or taking interesting close-ups.

Saturday Photography

The light today was so good that I could have quite happily spent the entire day taking photographs.

I’ve finally found a camera/lens combination that does justice to the windows in Hull Holy Trinity Church.

Hull Fair 2010

We went to Hull Fair tonight. I only ever go on the Big Wheel, and that is to take photographs. I’ve no head for heights, but if I view everything through the camera viewfinder I seem to do OK.  This new little lens seems to be pin sharp too, which is nice.

If you are a student at Hull and you haven’t been to Hull Fair you are missing out. It is huge, well managed and pretty good value if you get there for happy hour.

Helicopter

This is the one helicopter I’ve not broken yet. I daren’t fly it any more…

Breakfast of Heroes

At least the breakfast at the Renton Clarion is colourful….

A Walk Round Bellevue

Balloons in the park.

It was a beautiful day today. Flight didn’t leave until late afternoon, so I had time for a wander around and breakfast in Bellevue old town. Anything in the US can be called old if it was built before 1975 apparently.  But it did look nice.

On the way  back to the hotel.

Whitby Photos

Today was a Bank Holiday. Which means that we get the day off. We went to Whitby. The weather forecast was a good one, although the day did have a rather cloudy start. I took the big camera and a collection of lenses which was amply sufficient to really annoy number one wife as I kept changing them over every ten minutes.

I think this will do for the desktop.

I’ve been trying to get a decent picture of these beach huts for ages.

This is the walkway out to the harbour entrance. I quite like the colours.

Click on the images for bigger versions on Flickr.

Hull Classic Car Show

Went off this afternoon to a Classic Car show in Hull East Park. The park is a fantastic place. Beautifully landscaped gardens, wide open spaces and, today only, a lot of very shiny cars.

A nice shade of purple

I used to drive a Mini. But it was never as shiny as this.

Now, that’s what I call an engine.

Ring Light Fun and Games

The ring light does give your pictures a strange set of shadows I quite like.

A ring flash is a flash gun that fits around the lens of your camera. It is noted for taking photographs that contain no shadows (since the light source is around the lens) and being very expensive.

A ring light on the other hand is a ring of LED lights which fit around the lens and is much cheaper than a flash. It is a steady light, which means you can use it for movies as well as stills. The major disadvantage is that it is not as bright as a flash. As far as I’m concerned this is not a huge problem, since I really want to use the light for close ups.

If you want something for your SLR that will give your pictures a bit of extra pop, and is great for portraits (no shadows means no wrinkles) then I’d recommend that you take a look.

Saying Au-Revior to Concorde

Now, that’s what I call a flight deck.

We went to see Concorde at Filton today. I always feel a bit sad when we go over there. The plane is amazing but it doesn’t deserve to be stuck on the ground. It really should be out there doing what it does best, and what nothing on earth can do any more.

This time the affair was even more poignant because as of later this year the plane will not be open for visitors at all, which is really sad.

Anyway, I took the big camera and a selection of lenses and tried to get a few shots.

Not surprisingly the team at Bristol is very busy at the moment as people take their last chance to see the plane for a while, but if you can get yourself down there you won’t regret the trip.

Little Weighton Steam Rally

I think this is my favourite picture of the day.

Took the camera, and a bunch of lenses, down to the Little Weighton Steam Rally today. I went last year and really enjoyed myself taking pictures. So this year I did it again. By way of an experiment I put the telephone lens on the camera just to see what difference it makes to the results you get. Great fun. I could do close ups from a great distance and get some lovely out of focus effects like the one above.

The event is on tomorrow too, so if you like the smell of hot oil, burning coal and the sound of steam, you should go along there.

Gloves

Tractors in Line

Foden.