Fast <f2.8 wide angle lens for astro work 4x5" <f=90mm

[Dr Klaus Schmitt]

Any ideas what to recommend - a friend of mine is looking for one. All I coudl recommend was way to expensive
or impossible to come by (Aerial lenses etc.). [any ideas Dan?]

[Dan Fromm]

Klaus, since you asked, I'm not aware of any.

Your friend's coverage and maximum aperture requirements are killers. If he can relax his maximum aperture constraint there are several f/4.5ers at 90 mm and shorter that cover 4x5 from, in alphabetical order, Nikon and Rodenstock. If not, I think he's stuck in wishful thinking territory.

[Dr Klaus Schmitt]

Well Dan, more or less exactly what I told him; but I wanted to crosscheck for sure.
Wishful thinking indeed IMHO.

[Hugo Zhang]

Try this:

http://www.leicashop.com/vintage/komz-10025-uran27-p-5518.html

http://www.leicashop.com/vintage/carl-zeiss-jena-10cm-biotessar-prototype-p-5435.html

hugo

[Dan Fromm]

Hugo, I have a Uran-27. The lens flew on AFA-39 and RA-39 cameras, which shot 70 x 80 mm on 80 mm film. Not a 4x5 lens at all.

The 100/2.9 Biotessar isn't a 4x5 lens either.

No slower than f/2.8, no longer than 90 mm, and covers 4x5 isn't very available. Perkin-Elmer made a 3"/2.5 mapping lens that covers 4x5. Finding one is a challenge, so is paying ...

[genotypewriter]

Wishful thinking indeed IMHO.

What's more wishful than wanting to find such a lens is expecting such a thing to be fit for astro work (in the wide apertures).

If all your friend wants is a better SNR, ask him to increase the format size? For example a hypothetical 75mm f/2.8 on 4x5 is equivalent to a 150mm f/5.6 on 8x10...