Wordless Wednesday: 330

Take care!

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Throwback Thursday: photographing the invisible lights


I took this image about 6 years ago with an old DSLR (introduced to the markets in 2004). That camera only has a very weak high-pass filter in front of the sensor, so it is able to capture invisible parts of the light, too. The high-pass filter is designed to prevent the invisible portions of the light from reaching the sensor for getting better images.

To get sharp images in IR you have to adjust the focus. IR has a different behaviour when it comes to sharpness, then the visible light. Each wavelength has its own behaviour. In IR the sharpness point is a bit to the left. I.e. when focussing on an object 5 m in front of you, you have to shift the focus back a bit i.e. to 3.50m. You have to find out the correct setting by try-and-error. Back in film days nearly every lens has had these extra marks on the distance control for IR. Thus, I recommend using an old lens for IR photography. Anyway, use your display and check your images carefully for sharpness – despite it is very hard to recognise sharpness in all the reds on the small screen. 🙂

For the above image I put an 720nm IR filter on front of my lens for blocking all rays with a wave-length shorter than 720nm. I also have a 760nm IR filter for monochrome images. These filters extends the exposure time enormously. I have to use exposure times of about 1 second and above in full sun during the day. Thus I have to put my camera on top of a tripod, despite the sun 😦 To make things even harder, the filter in front of the lens won’t let visible light coming through. That makes the viewfinder dark. You can’t choose the right angle of view. Either you guess it, or you’re constantly detach and re-attach the filter to your lens for every image. Have fun 🙂

I like to let the filter in front of my lens and guess the right angle. It’s more fun and more interesting seeing the results. First of all, I do a manual white balance on green grass in full sun. Next, I dial in f8, ISO 400 (to shorten the exposure time a bit) and 1 second as a starting point. Photographing in raw is my default, so I don’t have to change this setting for IR.

I don’t have modified my camera to remove the highpass filter. That’s about 400€ depending on the exact kind of camera. On the other hand, you will not only get the filter removed (you get back short exposure times), but also the focus justified permanently. So, you don’t have to worry about the focus correction I mentioned above. You also usually get back a bright view finder. But the camera now has a certain filter inside: the camera is defined! And you’re not able to switch the filter i.e. to check out other wave-lengths.

For the above image I’ve used a filter, that didn’t block all visible light. So, I can get these color IR images.

I used an old APS-C DSLR, an old 28-70mm lens (qualified for capturing IR images), a tripod, a remote shutter release and much of sun 🙂 That’s not very wide (like 42mm on a FX camera). I wish, I’d have a wider lens. But, in film days they didn’t have had APC-C SLRs. So, such lenses aren’t available. 😦 I also won’t use a more modern DX lens, because they aren not tested under IR light. So, you probably see flares inside the lens resulting in ugly hotspots.

Take care!

P.S. it’s also possible to photograph in ultraviolet. But, in that part of the spectrum I don’t have any experiences – sorry guys.

making your camera strap interchangeable

DSC_7430 KopieEach camera comes with a strap. Usually a branded strap, shouting out the brand and sometimes even the model name of your camera. There are also unbranded straps available in the shops for those, who don’t like the design of the default strap or don’t want to show everyone “I have this high-pricy camera”.

There are also some camera straps for certain purposes available, i.e. a diagonal-strap. I own one of these and like it for certain purposes.  I always have the default strap on my camera. But i.e. for city tours I like the diagonal strap more, because it’s easier to change lenses out of my backpack. Usually I have a shoulder bag with me. And, having a shoulder bag, the default strap is fine. But, when having my backpack, the diagonal strap brings more security for the gear while changing lenses. Also on hiking tours with my backpack. Or, when having two cameras with me: the full-frame body with a wide-angle lens and the crop body with a tele-zoom lens.

All this comfort of a diagonal strap is paid with the necessity to remove the default strap. Having both of them on the camera is not a good idea. The diagonal straps are usually attached at the tripod socket. So, the attached default strap would stand in the way. Thus, remove it. Or, …. wait. That’s very complicated. Remove and reattach the default strap over and over again. So, I was looking for an easier solution.

A friend of mine has found some tiny carabiner at a climbing store. Unfortunately, I wasn’t able to get some too. I didn’t find any store having them. In some Chinese internet stores I found some tiny dongles made from plastic. But, I didn’t trust them. They looked too fragile, although there were offered for cameras. My camera weights 760g and the default lens another 710g. My tele-zoom lens actually 1,570g.

Finally, I got an idea. Lets have a look at a fishing store. Here you can find some tiny gear to attach fishing-hooks to the fishing-line. And, a catched fish brings many kilos on the gear while trying to escape. So, the material has to be very strong. I checked a store and was able to get some suitable connectors. The hooks are good for 88kg!!!! That’s way more than I need. But, hey, it’s fine!

Now I have remodeled my camera straps and I like it very much. I now have it for about two years and I’m very happy with the solution.

Happy snapping 🙂

DSC_7409 Kopie DSC_7421 Kopie DSC_7426 Kopie

WPC: Abstract

600_3284-sc_wThis week’s topic for the weekly photo challenge by “The Daily Post” is “abstract”

Guess, what it is 🙂

Take care have a great weekend!

(as usual, you can see the photo enlarged, when clicking in it)

 

Update:

The answer is: it’s a kind of fan. The fan has a diameter of about 1,50m, that approximately 5 ft. It’s part of a huge turbine. Several layers of these turbine wheels are stacked one after another. In the image you can see the blades four of these wheels. In the foreground you can see another three of these wheels, but these are surrounds by a riveted metal bands.

I illuminated it with my speedlight, that was covered with a blue gel. The flash comes from the lower right side. Thus, each blade throws its shadow on the next blade, while the lights falls of to the background.

Thanks for taking part in the riddle and trying to guess the answer!

Monochrome Madness 3-01

Welcome to our third year of Monochrome Madness organized by Leanne Cole. Each week several photographers from all over the world send in monochrome images. You can see them all on Leannes web site. Mine is here 🙂

mm01-610_0420-edt_wI took this image in Norway last month. It’s a bridge going over a fjord. The bridge hast to be so high above the water to give enough room for the large ships to pass below the bridge securely.

 

Take care!