camera lens bokeh discussion.

**Neil Nicholls** · 03-15-2007, 05:53 AM

Originally Posted by kwun

Neil is that directly from your 50/1.4 AIS? if so, i must say that the current production 50/1.4 AF-D that i got has much worse looking bokeh.

yep, errr with a UV filter. at f/1.4 and f/2.0
it's a made in Japan, serial 3849751 if that tells you anything

***kwun*** · 03-15-2007, 05:55 AM

Originally Posted by Neil Nicholls

yep, errr with a UV filter. at f/1.4 and f/2.0
it's a made in Japan, serial 3849751 if that tells you anything

thanks. and it does confirm my believe that at f/1.4 the shape of the bokeh should be circular. and that also means that any detection of heptagonal shape in your original flower photos is purely imagination of the viewer.

**Neil Nicholls** · 03-15-2007, 06:13 AM

Originally Posted by kwun

any detection of heptagonal shape in your original flower photos is purely imagination of the viewer.

I guess you mean pentagonal, but it may not be imagined. There are a lot of little stalks sticking out all over the place that could produce that effect.

**Neil Nicholls** · 03-15-2007, 08:03 AM

Originally Posted by kwun

Neil is that directly from your 50/1.4 AIS?

sorry, I don't think it is AIS. It's older than that, a K-series according to
http://www.photosynthesis.co.nz/niko...html#50%20fast

here's apicture of the lens
http://img411.imageshack.us/img411/4527/dsc00079cx5.jpg
on the silver ring, there is the big black line to indicate aperture
but what are the other smaller coloured lines for?
and what is the little red dot?

***Cheung*** · 03-15-2007, 09:56 AM

Those markings could be the depth of field markings at various apertures.

**red00ecstrat** · 03-15-2007, 10:47 AM

cheung is absolutely right and that little red dot is an infrared focus mark.

**Neil Nicholls** · 03-15-2007, 10:55 AM

Originally Posted by Cheung

Those markings could be the depth of field markings at various apertures.

ahhh, that makes sense, thanks.
some googling makes me think the red dot is a focusing mark for infra-red.

**Neil Nicholls** · 03-15-2007, 10:55 AM

Originally Posted by red00ecstrat

cheung is absolutely right and that little red dot is an infrared focus mark.

Thanks, I was just finding that out when you posted

***kwun*** · 03-15-2007, 02:18 PM

here is a the bokeh quality of a recent production 50/1.4AF-D at f/1.4. as you can see, it is pretty ugly. but as mentioned, it is a circular pattern as it was shot wide open.

**taneepak** · 03-15-2007, 09:44 PM

Originally Posted by kwun

here is a the bokeh quality of a recent production 50/1.4AF-D at f/1.4. as you can see, it is pretty ugly. but as mentioned, it is a circular pattern as it was shot wide open.

This is very poor bokeh. Its edge is bright and too well defined. Imagine this same bokeh as the sun and then a thick cloud moves in to cover the sun completely, you will then see a good bokeh with no distinct edges and more fuzzy-like.