B&L 12x15

[Mike Cockerham]

I have a B&L 12x15 lens in a barrel. I know that this lens will cover my 12x20. I have seen this lens listed in a Ilex shutter . Does anyone know which one?

Thanks Mike

[Michael Kadillak]

Save yourself a ton of money and mount a Packard on the front of your lens. My experience with 12x20 and exposures at f90 and f128 force me to become so familiar with reciprocity that I though it was my middle name. Only reason IMHO that anyone truly needs a shutter with the variables you described in your post is to reach accurately below the sub 1 second realm.

Call Grimes and check it out for yourself. It will more than likely run you over a grand after it is all said and done. That is a big Ouch. Find a used Packard shutter and you are talking hundreds and damn if I can tell the difference in the produced images. Grimes did some unique things for me to accomodate my needs with a Packard on my 35" Red Dot Artar that I will be happy to share with you if you are interested.

Cheers!

[Ernest Purdum]

Mike, I think you need to provide more information about your lens to get a complete answer. What is the maximum aperture? Does it have a name, such as Tessar or Protar? Is there a "Series" designation?

[Mike Cockerham]

It is a 12x15 F12.5 series IV.

Mike

[CP Goerz]

If you switch cells from front to back you'll get better performance too.

CP Goerz

[Ernest Purdum]

Mike, I do have a little information, but I hope you don't trust it too far. The listing I have shows the available shutter as a Number 2 Volute. Siunce the lens is a B&L, a B&L shutter would make sense, I think the one in Ilex was likely a remount, since I think this lens was out of production before B&L stopped making shutters. The size of the Volute suggests that the lens could probably be mounted into a Number 3 Ilex. It would be a good idea to verify this before laying out much money for a shutter, though. The S.K. Grimes people could perhaps tell you for sure by just an email. If not, they could, of course, give you a definitive answer and an estimate if you sent the lens to them. This would, of course, be expensive, since it is a job demanding high accuracy. If you could provide the shutter, this might reduce the cost somewhat.



You are right concerning the coverage. The larger sizes (12" X15" through 24" X 30") were rated at 85 degrees, and your size was shown as covering 16" X 20" at the smaller apertures.



I may have some more information. I'll take a look tomorrow.

[Mike Cockerham]

Thaks Everyone

Looks like I will look for a Packard or keep on using my lens cap.

CP are you saying that this lens is convertable to another focal length?

Thanks

MIke

[Michael Kadillak]

Grimes put a series of machining recesses in the lens receiving flage that fits onto the front of the lens that accepts a rubber gasket to provide a solid "base" for the Packard assuring such that it will not move unintentionally or will be able to fall off the front should you be shooting at any downward angle. Very ingenious design.

The way I look at it every dollar you save lets you purchase more ULF film. Last time I checked, they were not exactly giving that stuff away.

Cheers and have a great time with your lens!

[Jeff Liao]

If you switch cells from front to back you'll get better performance too.

CP Goerz

Dear CP Goerz,

switch cells from front to back can improve performance?
what is the reason?

thanks

Jeff

[Aaron van de Sande]

Usually you want the longer cell in the front, although I don't know how this lens is set up.