Which F-Stop for starry street lights

[panoramer]

Hi there,

I do a lot of HDR panoramas. What I try to accomplish is to get stars on street lights on cityscapes. But whenever I try to go for a higher F-Stop I get diffraction around to city lights. Does anyone of you have some experience?

X-E1 with 14mm

Thanks  

[frandom]

I took these night shots with your same gear (X-E1 + 14mm): f/18 and I got starry street lights

 

Arch of Constantine by Domenico Franco

 

Il colosseo sotto la luna by Domenico Franco

[Dis]

Hi there,

I do a lot of HDR panoramas. What I try to accomplish is to get stars on street lights on cityscapes. But whenever I try to go for a higher F-Stop I get diffraction around to city lights. Does anyone of you have some experience?

X-E1 with 14mm

Thanks  

Just open aperture one step from minimum.

[cug]

I found the XF14 not to be too great in that regard. The 18-55 on the other hand does this very nicely:

 

[KeenanRIVALS]

I thought this was based on shutter speed.

[mattcosta7]

It will depend on the style of aperature blade, and the aperature.   The smaller the aperature, the more defined stars you'll get.  The sharper the aperature blades, the more defined stars you'll get.   It has little to do with the shutter speed, (although they'll lengthen a tiny bit with a longer shutter, and generally you'll need a longer shutter to accodomate a night shot with an f/11 - 22 shot).

 

the 14, for instance, has VERY rounded blades, so you'll have a hard time getting much starlike from it. 

 

The 10-24 is a bit better at it.  the 18-55 also. 

 

The good news is that a large number of older, cheap lenses tend to have sharp blades.  If you find somehting with an odd number of blades, you'll get double the number of bursts as you do blades. If you have an even number, it's the same.  (so, 4 bladed aperatures have 4 lines. 5 have 10 lines, 6 have 6 lines, 7 have 14 lines, etc).

 

Rokinon/Samyand 12 is decent, voigtlander's 15/3,5 is great, and there are many many others.   Bokeh on these won't be as pleasing wider, because of the sharper blades.

[mattcosta7]

I forgot, an additional bit.  There are filters that you can screw on to get this effect as well, such as these:

 

http://www.bhphotovideo.com/c/search?atclk=Star+Effect_8+Point&catName=Star-Spectral-Effects&ci=119&N=4026728337

[SeetohLang]

Do you find the diffraction is linked to exposure length - does under exposing help minimize it? 

 

For reference regarding stars, here's f16 on a XF 23mm on an X-T10

 

 

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