Sunday, July 12, 2009

Boh - keh - ing !

I'm not a fan of bokeh thingy. I have no idea how to see and how to judge the quality of the area on the picture where the part is out of focus is creamy or not. But my recent play around with my friend's newest 50mm F1.8 lens got my attention in playing with the shape of the bokeh for different lens. This lens is one of the latest prime lens that is fast with big aperture. Wide open at F1.8, couple with "usable" ISO 800, it basically eliminates the worries of hand shaking and blur picture, but does not guarantee a sharp picture because of extreme shallow depth of field. But I'm not interested in DOF, but the shape of the bokeh from this lens.

Here is one pic I took during my only 1 night testing of this lens. Oh, about the set-up, I placed my Legoman on the edge of the window of my apartment, and there are some street lights on the housing estate not far from where I stay, a perfect place to test the bokeh shape, right ?

Hmm... the shape of this lens (50mm F1.8) does not look circular when at wide open. Is this what they call "cat eye bokeh" ?? I would expect to see a circular one because when the lens at its widest aperture, the shape of the aperture is near circular one. And why the shape of bokeh isn't circular one is beyond my understanding.

Then, I put on a lens that bears a blue label on it, and do the same shooting, and I got this :

Well, at its widest open at F2.8, the shape is near circular. Nice, right ? But if look carefully, one can easily see that the bokeh is kinda "hard". And this pic really look like a paranormal picture to me. "I capture orbs !" and hell lot of theory will come out just looking at my pic. LOL

Forget about the orbs !

Then something got me thinking: is that true that only big aperture lens can capture this kind of orb pictures ? No, is the answer. A kit lens which is having a aperture of F3.5 - F5.6 still can take orbs pic. No believe ? See example below :

Depend on lens, the one I am having now (not kit lens), the shape of the bokeh start to take the un-circular shape at F4.5.

If I remember correctly, the kit lens has the magnification of 1:4 similar to the lens I'm having now. Hence, at the most tele zoom of kit lens, and at aperture F5.6 (the widest of kitty), the kitty is capable to capture the orbs picture.

Even at F8.0 still can get orbs pic ! Please mind the blur pic, I was lazy to set up my tripod ! LOL

And further closing the aperture to F9, no orb can be capture in the pic. Probably the aperture is too small to capture the orb.

And then I was wondering, can a cameraphone capture the orb pics ? No harm giving it a try, right ? So, same set-up, setting my camera phone to macro mode, and shoot a picture :

Well, there are orbs in the picture ! LOL. Too bad my pns DSC H1 is not with me now. I bet I still could get the orb pictures from my H1.

Ok, enough of testing, and I wish to end my post with one of the picture I took few days back that I like very much.

The lego spaceman is still wondering, which planet has he landed ?

1 comment:

albert said...

The cats-eye bokeh effect happens when the front element is not big enough. You can see it from the back, when you move the lens about, that the 'edges' of the front will appear from the back.

The Sigma 50mm F1.4 does not have cats-eye bokeh, because its front element is so big it needs a 77mm filter!

So I guess they redesigned this 50mm F1.8 DT so that it's like the 50mm F1.4 on full-frame - with cats-eye but in APS-C.

The blue logo lens also has a bit of cats-eye (top-left and top-right).