Sunday, 16 May 2010

Cheap and simple macro soft box

When taking macro pictures, or pictures of fairly small objects in general, a common problem is to get the lightning right. More even lightning can be achieved by using a "soft box", essentially a contraption that spreads light from one (or a few) light sources over a larger area.

A very cheap and simple soft box is a transparent bucket, like this one:

Preferably, it should have as neutral density as possible. If it has some colour tint, the images will get the wrong white balance. It is of course possible to adjust the white balance later, especially if you're using RAW images, but it is better to have as correct colours as possible from the start.

When photographing the object, place it inside the bucket, with the light source on one side, or from the closed end, like this:

In this case, I used a Panasonic Lumix GH1, with an Olympus 50mm f/2 macro lens. This combination can only be focused manually, which is no problem for macro use.

The light source is simply the sun light coming from the window on the top side of the image. One could also have used a flash pointing towards the side of the bucket, however, an off camera TTL flash would have been preferable, which is probably not so common for people to have for this system.

Here is an example picture, taken with (left) and without (right) the softbox. As you can see, the softbox image has softer contrasts. Besides, the picture taken without the softbox has reflections from the window. The right image also has some shadows next too the feet, which you may need to edit out later.

I used ISO 100, f/5.6 for both images. The shutter speed was 1/3.2 second for the left image, and 1/5 second for the right image, since the softbox steals some light.

Here is another example image, showing a Pelikan M425 piston filler fountain pen. I used f/13 to achieve enough depth of field.

Saturday, 15 May 2010

Future use of MFT lenses

One of the fun things with the Micro Four Thirds (MFT) format, is the short flange distance (20mm), which enables the possibility of making adapters for a number of formats. There are cheap, abundant adapters for many legacy formats, e.g., Nikon F and Pentax K, to name a few.

When MFT becomes legacy

However, the flip side of the coin is that some day, inevitably, MFT is also going to become a legacy format. What happens with your gorgeous, and expensive, MFT lenses then?

Let's say that the worst case scenario is that, due to competition, the MFT system loses so much volume that it is abandoned by Olympus and Panasonic. It doesn't seem likely now, but stranger things have happened.

You can still use your old cameras and lenses, of course, but at some point you will want a newer camera, due to new features and better image quality. Can you still use your MFT lenses on some camera from another system?

If Samsung NX becomes dominating

The Samsung NX format is one of the competitors in the mirrorless system category. Let's say this format becomes dominating. Can you use your old MFT lenses on this format through an adapter?

In short: No. It's not possible. The Samsung NX format has a longer flange distance (25.50mm), meaning that even if you made a very short adapter, the MFT lenses would not be able to focus to infinity. You could only use them as short focus macro lenses. Which is not very useful.

If Sony E becomes dominating

The Sony E format was introduced for their new NEX series. It has a flange distance which is 2mm shorter than the MFT format. This is good news, because 2mm, while pretty short, is probably enough to make an adapter for using MFT lenses on Sony E. The Sony E format also has a wider flange diameter, which makes it easier to design an adapter.

However, the MFT lenses are pretty useless without the possibility to operate the focus and the aperture. And both are operated electronically, controlled by the camera. So an adapter must have the relevant software to interpret the Sony E signals, and translate them into something that the MFT lenses understand.

This kind of electronic communication might sound easy, however, it is probably far from trivial. And at best, your autofocus would probably be very poor, both the speed, and, possibly, also the accuracy.

For a comparison, let's consider the Canon EF system. There are adapters for using Canon EF lenses on MFT cameras, but none of them can control the aperture or the focus. So the probability of getting future adapters that provide this feature for MFT lenses seems pretty slim, given that there are many magnitudes more Canon EF lenses out there than MFT lenses.


The conclusion is that if the MFT system is abandoned, your lenses are more or less useless.

On the other hand, there are some rumors now that the modular Ricoh GXR system will include a Micro Four Thirds mount/sensor module. If launched, this will enable mounting a MFT lens to the Ricoh GXR camera, with an adapter mount/sensor module.

Update December 2010

Since I wrote this article, an adapter for using MFT lenses on Sony E cameras (NEX) has actually emerged.  However, since it has no electronic contact, it can not control neither the focus nor the aperture.  So you're stuck with a focus around infinity, and the max aperture.  You can, however, use it with the Cosina Nokton 25mm f/0.95, which is a completely manual lens, with a mechanical focus ring, and a mechanical aperture ring.

Wednesday, 12 May 2010

Example video capture, GH1+Lumix 20mm

Here is an example video recorded without using a tripod, using the Panasonic Lumix GH1, and the Lumix 20mm f/1.7 pancake lens.


And a larger version of the same video:

As you can see in the video, the focus is hunting a bit back and forth. This could be due to selecting spot autofocus and the smallest focus area. Perhaps it would have been more calm using multi area focus.

Also, in this case I am using the camera firmware v1.2. The new firmware v1.3 available on May 10th, 2010 is said to improve autofocus performance during video recording, and may have solved this focus hunt problem.

When using video mode on the GH1, the camera will focus continuously, even if the focus selector is set in AFS. According to my knowledge, there is no mode that allows for autofocus when starting the recording, but keeps the focus constant when filming. I think this is a drawback with the camera. It is of course possible to select AFS, pre-focus, and then set MF before starting the video recording. But this is a somewhat awkward procedure.

The recording was done with the AVCHD format, at 720p and 50fps. My version of the camera is PAL, hence I am not able to record in 60fps. I used HandBrake to convert the stream to H.264, which is better suited for uploading.

The image is also a bit jerky, but I can only blame myself for not keeping the camera stable.

The video was recorded in Gamla Stan, Stockholm, Sweden. The musicians are singing "Dina ögon är som knivar", a Vladimir Vysotskij song translated to Swedish. The band is called Carl Oscar Nygrens kalas och nöjesorkester.

Saturday, 8 May 2010

"Home made" hood for the Lumix 20mm f/1.7 pancake

The Panasonic Lumix 20mm f/1.7 pancake is a brilliant lens, but it does not come with a lens hood. Flare is not a big issue with this lens, but a lens hood is still good for protecting the front element. Some people use UV protection filters for the same effect, however, adding another glass layer will reduce the image quality to some degree.

One option is to get a cheap third party hood designed for the Leica Summilux lens, to screw into the front 46mm filter thread. However, this hood adds some bulk to the lens, making it less compact. The compactness is one of the desirable features of the Lumix 20mm pancake in the first place.

In an attempt to find a low profile hood that looks more like the hood for the Pentax 40mm f/2.8 pancake lens, I bought a cheap 46mm to 37mm step down ring. The ring is essentially a short cylinder with 46mm threads on the outside, and 37mm threads on the inside.

The ring is made out of light metal, and is extruded on the rear side to save some weight:

Step up and step down rings should be used with care with the Lumix 20mm pancake. When powering down, the lens retracts the front assembly slightly into the chassis, which will jam and possibly damage the focus mechanism if you attach a ring which is too wide. The following picture shows that this step down ring is not too wide, and can be safely used with the Lumix 20mm pancake lens:

Looking at hoods, you will note that they are usually ribbed and matte on the inside. This is to avoid having light reflected into the lens. Since the inside of the step down ring is threaded, it already has the right shape. However, the metal is still a bit shiny. To make it more matte, I applied some matte black enamel paint on the inside threads. Wanting to retain the stealthy look of the lens, I also painted the front and the side of the ring:

Here is the lens with the "home made" hood attached. This hood does not cause any additional vignetting.

You will probably want to have a front lens cap as well, and you can get a 37mm cap which fits into the front threads of the step down ring. Both the step down ring and the front lens cap can be found on various auction sites.

Saturday, 1 May 2010

Lumix G 45-200mm f/4-5.6

The Panasonic Lumix G 45-200mm f/4-5.6 Mega O.I.S. is the value tele zoom from Panasonic. While not exactly cheap, it does provide a good value for money, with a maximum of 400mm tele (35mm film camera equivalent), an excess of 4x zoom, and optical image stabilization.

The picture below shows the lens at 45mm (left), and extended at 200mm.