Fog filters

Marty · Post by **Marty** » Tue Aug 09, 2011 2:49 am

Any one experienced with using fog filters on constellation photography? They selectivity enlarge the bright stars so that you can easily pick the main stars of the constellation above the background fain stars. There are two types A and B in strength. Wondering about the strength, don't want to overdo it.

Eg
http://t0.gstatic.com/images?q=tbn:ANd9 ... AKxDJG2rcw

I'm looking at these Hoya filers
http://www.camerafilters.com/pages/fog.aspx
What do you reckon, A or B?

Marty

David Frydman · Post by **David Frydman** » Tue Aug 09, 2011 8:45 am

Dear Marty.
I haven't the fogiest.
Sorry for that.
The photo of Orion seems to display spherical aberration on the bright stars
At least it looks like it. Or maybe as taken with a soft focus lens.
The photo seems to be taken at full aperture or with round form aperture blades.
I wonder if the same effect might be to use a 50mm f/1.4 lens at full aperture or a fast 35mm focus on full frame at full aperture.
Perhaps an older lens is more likely to show this efect.
Or if you want to buy the filters perhaps try them first.
I think a similar soft focus effect is achieved by smearing vaseline on a clear filter.
Just some thoughts.
Regards, David

LeoLion · Post by **LeoLion** » Wed Dec 07, 2011 7:57 am

Hi Marty , I think that what you are looking for is the Akira Fuji effect as in http://www.davidmalin.com/fujii/fujii_index.html . David Ratledge has a webpage on the technique using Iris (free) here http://www.deep-sky.co.uk/imaging/constell/constell.htm . The Buil command is here http://astrosurf.com/buil/iris/new414/new414_us.htm . I like the effect when you want to get the constellation shape over to an audience. Hope this helps,
Len E

Marty · Post by **Marty** » Thu Dec 08, 2011 5:04 am

LeoLion wrote:Hi Marty , I think that what you are looking for is the Akira Fuji effect as in http://www.davidmalin.com/fujii/fujii_index.html . David Ratledge has a webpage on the technique using Iris (free) here http://www.deep-sky.co.uk/imaging/constell/constell.htm . The Buil command is here http://astrosurf.com/buil/iris/new414/new414_us.htm . I like the effect when you want to get the constellation shape over to an audience. Hope this helps,
Len E

Thank you LL . This is just what I was looking for

Marty

Marty · Post by **Marty** » Wed Jan 04, 2012 11:36 pm

I downloaded and installed Iris 5.59 and tried "SBLUR 5 7" command (recommended example in the tutorial link you provided) on a typical star field image. It failed reporting the command is not recognised!

According to the release list SBLUR has been implemented since version 4.49

Any clues why it doesn't work?