Question on a 15mm f/3.5 ai-s

[richardHaw]

this is odd. it shouldn't alter the focusing at all. If your lens cannot focus beyond 1m then it means that it is too far from the film plane, like you have a PK-13 extension ring attached to it

[pluton]

My understanding is that all filters alter the focus.  Most, in common use, alter it so little(in the plus diopter direction, by the way) that the effect can be ignored.  This is not the case with the lenses under discussion, the rear-filter 15/3.5 AiS and FX fisheyes.

[JohnMM]

this is odd. it shouldn't alter the focusing at all.

Have a look at ...  http://dougkerr.net/Pumpkin/articles/Glass_Plate.pdf

[Bjørn Rørslett]

From the last equation therein, with refractive index 1.5, the displacement is 1/3 of the thickness of the filter. As already stated.

[richardHaw]

aha! 

[Wally]

Searching on the internet the availbility of  these filter sets brought up nope, may have to get a nikkor 16mm fisheye for that ; without the corrective glass element  the minimum focal distance shortens.

http://www.ebay.com/itm/152306840847?ul_noapp=true
located in Japan though...

[Bjørn Rørslett]

No problem. They ship world wide

Thanks for the link, I got an alternative filter to my current L1BC's.

[Bjørn Rørslett]

An eBay search for "Nikon bayonet filter L37C" will, however,  bring up a number of these items. All of which seemingly are located in Japan, but again, shipping is world wide. Prices were acceptable as well.

[Wally]

Question to the experts: which advantages if any provides the discussed lens over the AF-S 14-24mm? I had one of these 15mm/3.5 but unfortunately sold it 

[Bjørn Rørslett]

Marginally smaller. Aperture ring for optimum control. High 'feel-good' factor. No zoom (doh). Flares more. Two-thirds of a stop slower. Can use rear-mounted filters.  Very low geometric distortion unless used in the near range, where CRC kicks in.

It also has less efficient coatings and has a softer more rounded rendition than the 14-24. There is more CA but usually this is easily cured by the RAW processing software.

[Jakov Minić]

Question to the experts: which advantages if any provides the discussed lens over the AF-S 14-24mm? I had one of these 15mm/3.5 but unfortunately sold it 

If any is very questionable
I tried the 15/3.5 thanks to Bjørn in Scotland. It was mounted on the Df and I never clicked with that lens. I remember the terrible flares and ghosts that it produced. Not my cup of tea.

[Fons Baerken]

Have tried 2 copies sofar some differences i noticed on sharpness and distortion, flare and fall-off between these two.
Indoors architecture seem the better option.

[Bjørn Rørslett]

This is either a lens you take a liking to, or the very opposite. Give it a try and decide for yourself, I cannot offer better advice than that.