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.

Conclusion

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.

video

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.



Size

The lens is somewhat longer than the Lumix G HD 14-140, to the left in the picture below, and a little bit slimmer.


Autofocus

The autofocus is fast and virtually inaudible. On the other hand, the aperture can be somewhat noisy, compared with the Lumix G HD 14-140mm superzoom, which is almost completely silent. The noise of the aperture can be compared with the Lumix G 20mm f/1.7 pancake.

When zooming, the focus is usually lost, meaning that you need to refocus, e.g., by halfpressing the shutter. This also applies when zooming during video recording. The focus is lost for a while, before the autofocus can regain the correct focus. This can be avoided by zooming very slowly.

Build quality

The lens feels well built. It has the usual steel mount, and the extending lens tube does not wobble when zoomed to the maximum tele. Operating the zoom ring, it feels reassuringly solid. However, it does not have the dampened feel you would associate with a pro lens.

At the front, there is a 52mm filter thread, and you can use a supplied hood with bayonet mount. The lens features internal autofocus, and so does not change length when focusing.

Some uses for the lens

The focal length starts at 45mm, which corresponds to 90mm for traditional film cameras. This is the traditional portrait lens focal length. However, with f/4 as the maximum aperture at 45mm, the lens can hardly be called a true portrait zoom. With an aperture of f/4, you need to make sure that the background is fairly smooth to avoid having it stand out too much from the subject.

Still, I think that this lens is a good alternative for portraits on a budget. The aperture at 45mm is better than the original kit lens, which is limited to f/5.6.

The focal length is also good for sports and wildlife photography, however, with a somewhat limiting maximum aperture range, you will not be able to use the lens for these purposes when the light is dull.
Here is an example picture taken with the lens at f=61mm, f/4.1, 1/160 s, ISO 100:


Due to the limited aperture, the background is not very blurred, and stands out quite a bit.

Bokeh

The bokeh of this zoom lens is quite nice. I would say it's surprisingly good for such a lens. Here is a comparison with the Leica Lumix DG Macro-Elmarit 45mm and the Panasonic Lumix G HD 14-140mm

Sharpness

The lens is not as sharp as the Lumix G HD 14-140mm superzoom. However, it can hardly be expected to be that sharp, considering the price difference. The 45-200mm is sharp enough for most uses in the shorter end, but in the longer end you will benefit from stopping down the aperture a bit, if possible, for the best results. At 200mm, you may need to use a tripod to be able to stop down the aperture. Otherwise, the shutter speed will usually become too slow for handholding the lens at f/8, even with optical image stabilization.

There has been some uncertainty as to the sharpness of this lens at f=200mm, full tele. To evaluate this, I have taken one picture with a high shutter speed, on tripod, and with shutter delay to avoid triggering a camera shake when pushing the shutter release button. I also turned off Mega O.I.S. The camera was Panasonic GH1.

Here is the full image, scaled down to 1000x750 pixels. It was sharpened a bit:



To better evaluate the sharpness, I'm providing centre and corner 100% crops from the picture. The 100% crops are not sharpened. You can click on the picture to see the full resolution image.

Here is a 100% centre crop for f/5.6, 1/1600 second, ISO 400:

And f/7.1, 1/1000 second, ISO 400:

And corner crops with the same parameters. First f/5.6:

And at f/7.1:


Here is another sharpness comparison with four other lenses at 140mm. The Lumix G 45-200mm lens does not perform among the best here, and when zooming further in to 200mm, it deteriorates more.

Compared with the Lumix G HD 14-140mm f/4-5.8

Do you need the Lumix G 45-200mm if you already have the Lumix G HD 14-140mm? The difference between the maximum tele values is not that significant. 200mm is 42% more than 140mm, but the difference in field of view is not very large.

On the other hand, the Lumix G 45-200mm does give a significantly larger aperture through their common range. Both start at f/4.0, however, the 14-140mm very quickly goes to f/5.8, while the 45-200mm is more linear. The following diagram illustrates this.



As this diagram illustrates, the tele zoom Lumix G 45-200mm has an edge when it comes to providing better aperture than the Lumix G HD 14-140mm. On the other hand, the 45-200mm, while having a larger aperture, is not always sharp enough at the maximum aperture anyway, meaning that you will often want to close down the aperture a bit.

Compared with the Lumix G 100-300mm f/4-5.6

Should you get the Lumix G 45-200mm f/4-5.6 or the Lumix G 100-300mm f/4-5.6? This is largely a question about your intended usage of the lens. The Panasonic Lumix G 45-200mm tele zoom starts at a typical portrait focal length, and extends to a long tele. This is a very versatile focal length range for everyday photography, given that you complement with at least one shorter lens. You could walk around with the 45-200mm lens attached to your camera, and find that it suits most subjects well, except when you want to photograph a wide landscape, cityscape, a group of people, and so on.

The Panasonic Lumix G 100-300mm tele zoom lens, on the other hand, starts at 200mm (film camera equivalent), which is already a long tele lens. Then it extends to 600mm (again at 35mm film equivalence). This essentially means that the lens is a specialized tele zoom, and not well suited for everyday photography.

If you intend to photograph sports, wildlife, or events where you are situated far from the action, then you could consider getting the 100-300mm lens. But otherwise, I think the 45-200mm lens will be more useful for most people.

So my advice is this: If unsure, get the 45-200mm lens. Then you can learn what tele photography is about, and, if you want, complement with the longer 100-300mm lens later. After all, the 45-200mm lens is reasonably inexpensive, and gives a good value for money.

Compared with the Lumix X PZ 45-175mm f/4-5.6

A newer lens with similar specifications was launched in 2011. I have compared the two lenses here. In a nutshell, the newer lens is smaller, lighter, focuses slightly faster, and with the power zoom, it is better suited for video use. It is also slightly sharper optically, in my opinion. To get all this, you need to pay a premium price. The older Lumix G 45-200mm f/4-5.6 remains a value tele zoom lens.

As a macro lens

This is not a macro lens, but like many other tele zooms, it can be used to take pictures at small items. At 200mm zoom, the minimum focus distance is around 1 meter, which gives a magnification of around 1:5. This means that you can take a picture of something with a diagonal of 5 times that of the sensor, corresponding to around 90mm x 68mm.

You are limited to using apertures at f/5.6 or larger at 200mm. This is hardly an issue with macro images, since you will usually want to close the aperture down to at least f/5.6 to get sufficient depth of focus. One drawback is that this lens is not very sharp at 200mm. So to get the best image quality, you may want to close the aperture down to f/8.

Here is an example image taken at 200mm, 1 meter focus distance, f/5.6, ISO 800, and 1/5 second shutter, GH1. The camera was leaned towards a fence for some support to avoid excessive camera shake.



Example image

Another example image, this one taken with f=189mm, f/5.6, ISO 400, GH1. The camera was handheld at 1/320 second. The image was rescaled and sharpened.



Example video

Here is an example video capture done with the GH1



Another video shot using the Lumix G 45-200mm lens on a GH2: