Low-cost LED background light for your computer

20150115-LED-Backlight-Title-001When working at a computer it is advisable to have some sort of background lighting. It is less strennous for your eyes if the contrast between the screen and the surroundings is not too big. I used to have a lamp on a boom arm which shone behind my iMac. But the lamp tended to get in the way when I moved my electric desk uü and down (read my post about my workspace re-organization here).

I decided to remove the lamp and find something else which would illuminate the wall behind my computer. On eBay I found a USB-powered LED strip. The LEDs are encased in a clear flexible plastic material, the backside of the strip is covered with adhesive tape.

I taped the LED strip to the back of my iMac and plugged the USB – finished. The solution is low-cost (the strip was around 11 €) and quickly installed. There are two minor drawbacks though. Firstly, you lose one USB port obviously. Secondly, when putting the computer in sleep mode (which is what I do, I rarely switch the iMac off) the light stays on since the USB ports stay powered in sleep mode. So you have to unplug the cable every time you call it a day.

WalimexPro (Samyang) 12 mm f2.8 full-frame fish-eye


Back in September 2014 Samyang announced a new lens – a 12 mm f2.8 fish-eye for full-frame cameras. A prototype was shown at Photokina in Cologne (see picture below) but the lens was not available until now.


Samyang 12 mm f2.8 as seen at Photokina (Cologne) in September 2014

I already own the Samyang 8 mm f3.5 fish-eye and it is a fun lens. You can see some sample images in my “urban” photo gallery on this website. But it is the version for APS-C sized sensors (Nikon DX cameras). I owned the Samyang back in the days of my D70s/D300s, and as I switched to full format the lens stayed as a full-frame fish-eye was not on the market (at least not a reasonably priced one).

The lens Samyang announced is not broadly available yet (Status: January 2015). It seems to be in the phase of introduction and getting it required some searching. I could have ordered it via eBay directly from Korea, but decided against it due to warranty reasons (although it was considerably cheaper). Finally I found the lens branded as “Walimex Pro”, sold and shipped from Germany for 549 €. WalimexPro is the house-brand of Foto Walser, a large online retailer for photographic equipment. They seem to partner with Samyang, selling their lenses under another branding.

Clicked, ordered, waited impatiently drumming my fingers, doorbell, postman, parcel, woot woot !

The lens is surprisingly similiar in size to the APS-C version, although it is for full format and has a larger aperture. The distortion is quite the same compared to the 8 mm at APS-C, but this is logical. An 8 mm at a crop camera equals 12 mm (x 1.5, which is the crop factor) at a full-frame camera.

In contrast to the 8 mm fish-eye the lens hood is detachable. Due to the bulbous front lens filters can not be attached.

When I mounted the lens there was a little more friction between lens and the camera’s bayonet than expected. Let’s say it is a tight fit, but I do not deem it to be a problem. The fish-eye is manual focus only, but the aperture and exposure information are transmitted. As you can see in the sample images below the lens is quite sharp (well, that’s what a lens is supposed to be). It covers nearly 180 degrees (well, it’s a fish-eye, but never fails to amaze again…). Please excuse the abundance of b/w photos. The weather is quite s#!tty these days and b/w seemed to be the better option.

As I already own a fish-eye lens (the Samyang 8 mm f3.5 for DX cameras, see sample images here, here, and here) I know what it can do. But I found it interesting to compare the three wide-angles I currently own: WalimexPro 12 mm f2.8 / Nikkor 14-24 mm f2.8 / Samyang 8 mm f3.5.

The focal lengths perform as expected. 12 mm gives you a distorted fish-eye look. The 14 mm show less distortion and a slightly smaller area of view (the Nikkor 14-24 is famous for its low distortion considering the 14 mm wide angle by the way). The Samyang 8 mm, being a DX lens, show a black frame around the border since the lightcircle which is projected onto the sensor is designed for a smaller area. After cropping the image to the middle section the field of view is nearly identical to the 12 mm WalimexPro.

That, by the way, is a nice visual proof that any focal length on a crop camera has to be multiplied with the crop factor to receive the same field of view on a full frame sensor (8 x 1.5 = 12).

Bottom line: A sharp and astonishingly wide lens. Image quality is great. A nice deal for all full frame owners out there. Price might drop over the next months. Absolutely recommended.

2014 in review

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog. Thanks for reading and looking forward to seeing you in 2015 n

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 47,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 17 sold-out performances for that many people to see it.

Click here to see the complete report.

Seasons greetings from lumenatic.com


20141202-Spam-001SPAM. From me. For you. I was too lazy busy to write a full-blown blog entry, therefore I am posting an image which I entered into the bi-weekly photo contest of the German photo podcast Happy Shooting. The topic of the contest was “Konserve” (“can” or “tin can”). You might notive that there is no watermark or signature on the image. Initially I placed my signature in the bottom left corner, but that looked odd and disturbed the symmetrical balance of the image. Moving the signature to the right had the same effect. So I decided not to implement any watermark or signature. Sometimes less is more.

The setup was very simple. A few sheets of paper and white cardboard as backdrop, two flashes for illuminating the background, one flash straight from above to illuminate the tin can. Here is the making-of image.

Post processing included cropping, straightening, overexposing the background with the “lights” slider and a circular gradient filter. In the last step some minimal perspective correction in Photoshop since I did not shoot the can 100% from the front. Total time with “studio” setup, shooting, post processing ca. 30 minutes.

Enjoy the image !



Two weeks ago I hung some birdfood in the tree right in front of out kitchen window. That gave me the opportunity to deposit the camera right in the kitchen and wait for the moment to make close-ups of animals feeding there.

One morning I was rewarded with a squirrel that munched away on the bird food. Photos made with the D800 and the Tamron 150-600 mm. It was 10 in the morning, but it was very overcast and not too bright, therefore ISO was set to 12.800. Yes, that’s a lot of grain in the images, but otherwise no photos could have been taken. With 1/320th of a second and f5 (f6 for some images) I was able to take images that were not too dark (tried 1/800th of a second but that proved to be too underexposed).

Anyhow – enjoy the images, share, like !

Golden Fairy Evolution


Every year in October the Tiergartenfest ist held. The Hannover Tiergarten used to be the royal hunting grounds, reserved to the king, his family and other noblemen. Today it is a public park where deer roam freely. Once a year a festival takes place in the Tiergarten. It is aimed at children with many fun activities: Exploring a firefighting truck or an ambulance, building birdhouses, tinkering small toys and pendants, having fun in a bouncing castle.

To enhance the atmosphere walkers mix in with the crowd, wearing colorful costumes. I managed to get this shot of a golden fairy:20141011-Fairy-Evolution-Original001

As you can see there are several unwanted elements in the shot (sorry kids !). Nothing the repair tool in Lightroom can’t handle. I made a 60 second video of the editing process. Mainly I used the repair tool to remove the people and the buggies in the picture. Note that not everything is perfect at the first try. I deleted the repair patch a few times and did it again to get better results. After I removed the unwanted elements I made some local adjustments on exposure and color, contrast and added saturation. Then I added some local exposure to the fairy using the brush tool to make her pop out and applied a vignette to the image.

The editing process took around 12-15 minutes. If you pixel peep you will notice that the patches are not perfect everywhere, but I’d say they are 90% perfect. Since the images are scaled down before I upload them to the web some of these “impurities” become so small you won’t recognize them anymore.

Here is the final result:20141011-Golden-Fairy-001


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