Saturday, 28 September 2013

E-M1 and GH3 comparison images

In a camera store, I was able to take some example photos with the Olympus OM-D E-M1, the most exciting camera news this autumn. The camera was apparently set up to take medium quality JPEG images only, around 3MB, and had the Olympus M.Zuiko 17mm f/1.8 lens.

I used my GH3 with the Lumix X 12-35mm f/2.8 for comparison, and was able to take photos under the same lightning conditions. Both cameras were set to Aperture Priority, ISO 200, f/2.8. I used the face detection feature, and kept a distance of about 1 meter to the subject. The shutter speeds were around 1/50s.

Olympus OM-D E-M1Panasonic GH3

Sunday, 22 September 2013

Bokeh part 2

I previously wrote about bokeh, describing what it means (the nature of the rendering of out of focus areas), how it is commonly used, and I also looked into how the aperture setting affects the out of focus areas in the picture.

This time, I want to look more closely at how the bokeh differs by lenses. I've tested some common fast lenses from the Micro Four Thirds lens lineup, laid out here:

Second row: Olympus 45mm f/1.8, Leica Lumix 45mm f/2.8 macro, Lumix X 12-35mm f/2.8
First row: Lumix G 14mm f/2.5, Lumix G 20mm f/1.7, Sigma 30mm f/2.8 DN and Sigma 19mm f/2.8 DN

Thursday, 19 September 2013

Fireworks video recording with the GH3 and Samyang 7.5mm fisheye

I've previously used the Panasonic GH2 for recording fireworks, and found that at the maximum video ISO 3200, I still needed to set a very slow shutter speed of around 1/10s to get sufficient exposure. The Panasonic GH3 supports video recording at ISO 6400. When using the Samyang/Rokinon 7.5mm f/3.5 fisheye lens wide open, I can use a shutter speed of 1/25s, and get a normal PAL 25fps framerate.

Here is the video I made, more information about how it was done follows below:

Sunday, 15 September 2013

180 degree shutter

One could say that video is just like photos, the only exception is that there is a series of still images composing the video stream. This works well for central concepts like focus, selective focus and background blur (bokeh), sharpness and so on.

However, there are some important differences too. One is focus pulling, to change the focus distance during video recording.

Another important video concept is the 180° shutter. Put shortly, this means that the shutter speed is twice that of the frame rate. So if you are in an NTSC country, e.g., USA, you would set the shutter speed to 1/60s when recording at 30 frames per second.

The name "180 degree shutter" comes from the construction of early film cameras. The shutter in these cameras was simply a rotating disc, with an opening that exposed each film frame. When using a disc with a 180° opening, i.e., a half disc, the film would be exposed half the time.

Why 180° shutter?

The point of the 180° shutter is to create motion blur. When you have movement in the scene, you'll want the movement to be slightly blurred. Using a faster shutter speed would yield stuttered motion, where the moving objects appear to be in different spots in each frame.

Monday, 9 September 2013

Hoods for prime lenses

One of the big advantages of the Micro Four Thirds system is the small prime lenses available. Many of these don't come with any hood supplied in the box. I don't think that using a hood with these lenses is a big deal from an optical perspective, but many people like to use hoods anyway. For lenses like the Lumix G 20mm f/1.7, I have noticed that some like to use a Leica like 46mm screw in hood.

Personally, I think the barrel shaped screw in hoods are a bit too bulky for the small pancake lenses. So I prefer to use a 46mm to 37mm step down ring as a compact hood.

Below is a picture of the Sigma 19mm f/2.8 lens with the original hood (left), and 46mm to 37mm step down ring as a hood (right):

Sigma 19mm f/2.8 with original hoodSigma 19mm f/2.8 with 46mm to 37mm step down ring as hood

But for keeping out light, which is better?

Saturday, 7 September 2013

Induro BHD1 ball head - Not recommended

Having a tripod with a good ball head is a necessity for anyone interested in photography. For a couple of years, I have used the Benro B2 ball head. While it is a cheaper knockoff of the Arca Swiss type ball heads, it still works fine.

However, the big locking knob stuck, so I was looking out for a replacement. The Induro BHD1 looked fine, with a similar layout of knobs, a large ball, and ergonomic grip surfaces on the knobs:

It has some flaws, though, which sadly makes it useless for me. One minor issue is that using the tripod tightening screws locks up the panoramic function. Most tripods have three locking screws that can be tightened when the head is mounted, to avoid accidentally unscrewing the head. You can see the tops of the screws in the picture of the Manfrotto 190XPROB tripod, a very good budget tripod, below:

If these screws are tightened while having the Induro BHD1 ball head mounted, the ball head does no longer rotate when opening the panoramic knob. Now, this is not an uncommon issue: I have noticed the same with other ball heads as well. It can be solved by tightening the screws only very little.

A far bigger issue is that when mounting a camera and framing a subject, tightening one of the locking knobs dislocates the camera slightly. This makes the tripod ball head very frustrating to use. It is pretty much impossible to frame your subject the way you want with a long lens, and it is even problematic with a shorter lens.

Sunday, 1 September 2013

New manual focus wide angle prime from Samyang

News has surfaced that Samyang will release an very wide prime lens, specified as 10mm f/2.8. So is this finally the compact wide angle prime that I have been waiting for?

No, it isn't. It is far from compact, as illustrated by the following comparison table:

LensSamyang 10mm f/2.8Lumix G 7-14mm f/4Olympus 12mm f/2
Minimum focus distance0.25m0.25m0.20m
Lens elements/groups14/1016/1211/8
Filter threadNANA46mm

Both the Lumix G 7-14mm f/4, which is extremely wide, and has a zoom, and the Olympus 12mm f/2, which is one stop faster, are much smaller and lighter than the upcoming Samyang lens.

So why are Samyang making the lens so large and heavy?