Info requested re Rodenstock chemco Apo-Ronar f/9 480mm

[zsas]

Folks -
I bought this at an antique/junk shop. Lens is in terrible shape (fungus and haze) plus some of the black paint under the first front element has started to flake off onto the glass. (see image). The iris works like a charm and stops from f9 to f260.

Is this lens pretty much useless or is this a good find? Paid very little for it so I figured I would “rescue it”. It was in a junk shop that had no heat/ac and has probably sat like that for years in the humid and frigid Midwest seasons.

I am not able to find much info re this Rodenstock chemco Apo-Ronar lens anywhere. Is this some sort of copy production lens? What is Chemco? I believe the focal length (480mm), allows for 1:1 reproductions from what little I could find re this?

Feel free to enlighten me what I have. I am really a 35mm/MF kind’a photog, but I always tell friends who ‘junk’ if something has lots of glass, is heavy, made in Germany and cheep get it and figure out later if it was a good buy later so I had to pick this up instead of let her sit through more painful days with no love.
Best!

 

[DanielStone]

rodenstock was the manufacturer

it was probably used for the graphic arts/reproduction(flat work primarily) industry. AKA "plate" making before digital platesetters

it'll work as a taking lens, and will cover 8x10 wide open, possibly larger when stopped down enough. Its "sweet" spot from what I've read is around F/16-22

it's multicoated, (see the multiple reflections in your 4th picture)

-Dan

 

[zsas]

Thanks for the info!

 

[domaz]

I've never seen one with "chemco" on it. No idea what that means- the font looks a little different as well, perhaps a company had it engraved? Get out some lens cleaning solution and a microfiber cloth and see how clean you can get it.

 

[anon12345]

I also have this lens.

http://www.prograf.ru/rodenstock/largeformat_en.html

Mine came from a very large vertical camera. I'm hoping I can utilize it as an 8x10 enlarger lens. If I recall, you can easily unscrew the front and rear elements for cleaning.

 

[Ian C]

This might shed some light on the “chemco” name appended to the Rodenstock process lens. This would have been a customer request that the process lenses used on chemco products also bear the “chemco” brand.

Similarly, we sometimes see Schneider lenses with the additional “Durst” name added to the barrel.

http://www.trademarkia.com/free-trademark-search/photomechanical

 

[Ian C]

With respect to post #5:

In theory the 480/9 APO Ronar could be used to enlarge 8” x 10” negatives.

Unfortunately, in most cases the magnification is too low to be practical for this format. The image area of an 8” x 10” film holder is about 195.5mm x 245.5mm.

In order to make a 8.5” wide projection to cover an 8” x 10” print we need 1.1X magnification.

That requires about 1925mm from negative to print. The negative-to-lens distance needs to be about 915mm. Much of that would have to be bellows to place the lens at the proper position.

To make a 20.5” wide projection to make a 20” x 24” print you need 2417mm from negative to print and 660mm from lens to negative for a 2.7X magnification.

You’ll need a really generous sized enlarger to accomplish this.

The above numbers are calculated from the Thin Lens Equation and aren’t perfect for a real-world lens, but the error usually isn’t much.

 

[anon12345]

With respect to post #5:

In theory the 480/9 APO Ronar could be used to enlarge 8” x 10” negatives.

Unfortunately, in most cases the magnification is too low to be practical for this format. The image area of an 8” x 10” film holder is about 195.5mm x 245.5mm.

In order to make a 8.5” wide projection to cover an 8” x 10” print we need 1.1X magnification.

That requires about 1925mm from negative to print. The negative-to-lens distance needs to be about 915mm. Much of that would have to be bellows to place the lens at the proper position.

To make a 20.5” wide projection to make a 20” x 24” print you need 2417mm from negative to print and 660mm from lens to negative for a 2.7X magnification.

You’ll need a really generous sized enlarger to accomplish this.

The above numbers are calculated from the Thin Lens Equation and aren’t perfect for a real-world lens, but the error usually isn’t much.

Thanks Ian for this data. All will be seen as I put together this 8x10 horizontal enlarger (DIY). Distances will be no problem in this configuration. As I only gave $5 for the lens, it wont be a big loss should it fail to perform.

 

[Ian C]

Horizontal projection makes this much more practical so long as you have sufficient bellows. There’s nothing wrong with using a good process lens for enlarging. I’ve use a 305/9 APO Nikkor for 8” x 10” negatives and later acquired a 240/5.6 EL Nikkor. I can’t see any difference in prints from the same negatives.