Tuesday, 23 July 2013

Meike/Neewer macro rings: Highly recommended

I have previously tested a number of low cost solutions to macro photography. Mostly, they are quite hard to use, for example because they don't support changing the aperture or focusing. I think I had the most impressive results with a reverser ring, however, the working distance becomes very short, and there is no aperture control or focus possibility.

Finally, macro extension rings with electronic contacts are available at a low price. They are marketed as Meike, Skyblue, Neewer, and probably more names, and one pack includes two rings: One 10mm thick, and one 16mm thick. My rings look like this:



Saturday, 20 July 2013

Smaller lenses, smaller apertures

Panasonic recently launched their third tele zoom lens, the Lumix G 45-150mm f/4-5.6. It is impressively compact considering the specifications:

LensLumix G 45-200Lumix X 45-175Lumix G 45-150
Max aperturef/4-5.6f/4-5.6f/4-5.6
AnnouncedSep 12, 2008Aug 26, 2011Jul 18, 2012
Length100mm90mm73mm
Diameter70mm62mm62mm
Weight380g210g200g
Filter thread52mm46mm52mm
Front lens element diameter37mm32mm27mm

So, how can Panasonic design a smaller lens with a smaller front lens diameter, and still retain the same aperture range, f/4-5.6? The answer is simple: They cheat.

Well, "cheat" may be a bit too strong word, as the aperture range is indeed f/4-5.6 for all of them. But what the specifications don't tell you, is that the aperture between the short and long ends is different. This diagram sums up my point:



If you took the average aperture over the focal length range, then you would see that the newer lenses have a smaller average aperture. Hence, while the specifications look the same, the smaller lenses are giving you a smaller aperture on average. I guess there is no way to avoid this: Panasonic cannot cheat the laws of physics. If they make a smaller lens, then the aperture must be smaller.

Monday, 15 July 2013

Panasonic Lumix DMC-3D1 review

The Panasonic 3D1 is one of the very few twin lens compact 3D cameras available. It is shown below with a Seiko diver's watch for scale:


Nowadays, many cameras feature 3D in their specifications, but they achieve this by letting you swipe the camera horizontally while shooting several images, and then stitching the images together for a 3D effect. While this does indeed give you a 3D effect, it is not a true 3D capture in the sense that the same image is captured at the same time from two different angles. Rather, if there is movement in the image while you are sweeping, you may be capture different images for the left and right frame, which will look bad. Also, this technique does not support video recording.

The Panasonic Lumix 3D1 has got two separate, identical lenses, each covering a 12.1 MP sensor. Sliding down the front cover reveals the lenses, and also powers on the camera:


In my review, I will focus mostly on the 3D features of the camera. When used as a 2D camera, it is nothing special at all, and I cannot imaging that anyone would buy this camera for 2D shooting anyway.

Tuesday, 9 July 2013

Micro Four Thirds sensors

The imaging sensor is the heart of the digital camera, and, hence, it is not hard to understand that there is a lot of interest and mystique surrounding the issue of sensors. In this article, I am trying to make a bit of sense of the various generations of sensors used in the Micro Four Thirds cameras so far.

Some of the information here is based on a bit of guesswork. If you think some of this is wrong, then please feel free to comment it.