Ross - London - Wide angle lens

[Oldhand]

Ross - London - 5 inch f/4 lens
Wide angle.
Check out those aperture blades.
I wonder what the 35mm equivalent is for this lens?
OH

[calvin83]

For info on internet, this lens is will cover 5x7" format. 5 inch is about 127mm. Use the info from here: http://en.wikipedia.org/wiki/Normal_lens

Image area of 5x7" film has a diagonal: (120mm^2 + 170mm^2)^1/2 ~= 208.087mm

Image area of 35mm film has a diagonal: (24mm^2 + 36mm^2)^1/2 ~= 43.267mm

Crop factor of 5x7" film: 43.267mm/208.087mm ~= 0.208

Thus, this 5" lens used in 5x7" format will have 35 mm equivalent focal length of 127mm*0.208 ~= 26.4mm


You can use this table if you do not want to the math.

[martinsmith99]

What will you be using it on?

[Oldhand]

[Oldhand]

OK, I have finally gotten around to taking images of the aerial photography camera that the Ross lens accompanies.
There are also 8 inch and 20 inch lenses, along with red and yellow (minus blue) filters.
The camera takes roll film and has/had a focal plane shutter of some kind.
A 30cm/12 inch ruler shows size.
Did I mention it is heavy..........
What to do with this camera and/or the lenses?
OH

[luisalegria]

Rig a spring back on it to take 4x5, make sure it registers correctly at infinity, and use it for landscapes.

[iangreenhalgh1]

Wow, you lucky bugger.

You have three awesome lenses there. the camera, not so useful.

What you have is a camera that takes pictures using a 5 inch wide roll of film, it's an aerial surveillance camera.

The Ross f4 5 inch is a superb lens, the design was ahead of it's time by over a decade. I have several copies because they made a hell of a lot of them during ww2 so they are very common in the UK. Yours is a rarer one though as it is a proper Ross one, most are not marked Ross and just have the broad arrow and W.D. or A.M markings and crown to identify them. The lens has 6 elements in four groups, a plasmat design with a cemented pair front and back and a pair of meniscii in the middle either side of the iris. Ross lenses always had superb quality brass barrels and irises, this one is no exception. It is in the form of a pair of cells mounted in a barrel, the cells are threaded 58mm and are a direct fit into an Ilex #4 shutter. The E.M.I. marking stands for 'Extra Marginal Illumination' and refers to the oversized front and rear glasses. The lens isn't actually f4, you will notice the iris opens a little wider than the f4 mark, it is actually f3.1 wide open. It is a very sharp lens, even wide open, but being uncoated (unless you have a rare postwar coated one) and having 8 air-glass surfaces, it has very low contrast and suffers badly from flare, particularly veiling flare. I intend to get the best of my copies coated sometime then mount it in an Ilex #4 to use it on my 5x7 camera, in that application it is the equivalent of a 26mm lens on 35mm.

The 2.9 8inch is a Dallmeyer Pentac, which is a 5 elements in 3 groups design very similar to the Voigtlander Heliar. If yours doesn't say Dallmeyer on it, it's probably not made by them, during ww2, lens production was spread across many contractors and a lot of the Pentacs were made by NOC (National Optical Co in Leicester). If it's in good condition, it is a superb lens, very good for portraiture on large format. I forget exactly what it covers now, it definitely covers 5x7.Again, this is a common lens in the UK but most are n terrible condition, the barrel is some form of alloy painted black and most of them are heavily oxidised with little paint left. I have one and it's in terrible shape, sadly. Many of these saw intensive use in photo-recon Spitfires during ww2 so are not in great shape, all those heavy landings are not good for optics. If you tell me all the text on it, I might be able to tell you where it was made.

The big 20-incher, that could be one of a few things, Dallmeyer, Wray, TT&H and Ross all made long aerial lenses to their own designs. If you tell me all the markings on it, I should be able to identify it. It's going to be a telephoto design so the back focus will be around 10 inches rather than the 20 you would have if it was a 'normal' lens. This also means coverage will be much less than you would expect from a 20 inch lens. Probably it covers 8x10, definitely covers 5x7.

So, what to do with it?

Unless you're a large format shooter, sell it. You might get more for it if you sell the lenses separately, removed from their heavy tubes, the Ross 4/5" in good condition is not worth a huge amount, but I would say you should be able to get 75ukp for it due to being the more desirable Ross EMI version, the vast majority just have military markings. The Pentac, if in good condition is worth probably twice as much, I'd say 120-150ukp. The big one, hard to say, probably worth at least 100ukp.

I just wish you were in the UK, because I'd have this lot off you, I collect British lenses and all three of these would also be very usable on my 5x7, I am actually looking for a good Pentac.

Let me know if there's any more info you need, I can dig some more up, this is just from my (admittedly sometimes poor) memory.

[Oldhand]

Thanks Ian for your response.
Here are some more images of the 8 inch lens.
Getting at the 20 inch is a bit more of a chore.
OH

[iangreenhalgh1]

That's a Pentac alright, and a nice one at that, most are nothing like so nice. See how there is a little gray oxidisation breaking through the paint on the edge of yours? Most have a lot more oxidisation than that, I've seen them where there is not a spot of black paint left anywhere and the whole thing is just gray rough oxidised metal. I suspect, rather than an alloy, they are made out of pot metal, quite possibly this is one of the uses they put the pots and pans they collected in 1940 for the war effort, they certainly didn't make aircraft with that metal, as they told the public they were.

Can't tell you who made it, if there was a two letter prefix before the serial I might have been able to, UU and VV designate Dallmeyer.

The 14A/ code is the contract number it was ordered under. I wish we had a database of Air Ministry contract numbers then we could properly identify the myriad semi-mysterious wartime and 1950s lenses that bear these codes.

[hoanpham]

What a nice set you have Oldhand

[Oldhand]

A couple more of the Ross without the housing.
OH

[Ultrapix]

IMHO this outfit must be kept as it is, and eventually sold to some military items lover

[iangreenhalgh1]

That Ross is a real beauty, I haven't seen one with the full set of military markings as well as the full set of Ross civilian markings, usually, they have one or the other, not both.

[philslizzy]

Ian's creaming his jeans here. A nice set of equipment.

Perhaps see if you can make some kind of focusing adapter for your Nikon and use the lenses for portraiture, I did it with an old large format lens. I think the camera and the bits are a fantastic collection and if it were me I'd keep the set together.

lovely!!

[Oldhand]

Ha haha ...... I have carried this camera and lenses around for the last thirty years and have always resisted the admonishments of my better half .....You never use it, you should get rid of it ........
(Funny how I came to have it. It was a part payment for a wedding photography job that I had done in the distant past .......)
We are downsizing and it has to go.
The camera can go to a museum. The "set" was collected over time by an enthusiast, but the lenses are from various eras and not all WW2 related, although some obviously are.
I would actually like to see the lenses used again if possible. I won't be using them but others might like to do so.
Thanks for your thoughts fellas.
Cheers
OH

[iangreenhalgh1]

I think the Ross is a very early war one, before they scaled up production and several other factories became involved, I should check the serial number.

I collect Ross lenses, I already have three of these 5 inchers but mine are all later ones with just the military markings. I have image samples from when I have mounted one on bellows, but they are on my old pc that died, I need to put the hard drive in a external caddy.

[Oldhand]

This lens is now listed on Ebay
http://www.ebay.com.au/itm/181190008640?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
Thanks Ian for your assistance with this lens and its features.
Cheers
OH