Lens N2 Shutter
Mounting
There are 2 methods of
custom mounting a lens. The first and most common
method of custom lens mounting is similar to a factory mount. The second method
of custom lens mounting is to front mounting a lens on to a shutter. We will
deal with this first and then come back to the other.
Custom lens mounting into a shutter is also done
in one of different 2 ways. The lens groups unscrew from the barrel and then
either the actual lens encampments are turned to fit and threaded to screw into
the shutter like this APO Garogon-S or
adapters are made that go between the shutter and the group like on this Series
IV 8x10 Protar. Custom
lens mounting regardless of what method is used the placement of the groups is
positioned precisely where they were in the barrel relative to their position
to the aperture when they are mounted into a shutter. This is critical.
Improper placement will create focus shift when stopped down. The aperture sizes on the barrel are
precisely measured and transferred to the aperture scale on the shutter. The
locations and numbers are then engraved on to the aperture scale. On some
occasions part of the factory barrel is used to mount the lens into the shutter
but this is not the norm. This is done for people who prefer the beauty of the
brass on classic lenses like the Goerz Dagor. By far the
most popular lenses to mount into a shutter are the APO Artar, Red Dot Artar,
APO Ronar, Protar and the Goerz Dagor.
Here is our Standard Pricing.
Front mounting a lens on a shutter is
done by making a mounting flange (like you would use to put the barrel on to a
board) but having the flange threaded so that it will screw into the front of a
shutter like this. The
barrels aperture is used in this type of lens mounting. This is a less
expensive option costing between $100 and $175 depending on the complexity of
the adapter. A wide range but with out having the part to look at, I can only
give you ball park prices and I prefer to error on the high side then come back
and say it will be less if possible than come back and say it will be more.
That’s just a bit easier to swallow I think. Front mounting a lens is
usually done for macro lenses as well as the shorter focal lengths of the APO Artar, Red Dot Artar and APO Ronar. Occasionally we front mount
a Dagor or a Protar. However when mounting such wide field lenses, some
vignetting can occur. Often a larger shutter will eliminate this. Shutters used
for this method should be oversize. A tight fit like a 480mm Apo Red Dot Artar
front mounted on a #4 ilex will have less coverage than one mounted into the
shutter due to vignetting.
The advantages are:
·
Less expensive
·
One shutter can be used for several lenses
·
Barrel may have smaller apertures than possible in the
shutter
The disadvantages are:
·
Requires a larger more expensive shutter most of the time
·
With wide angle lenses or to small a shutter vignetting will
occur
·
This reduces the size of your image circle (avoid if
possible)
·
Positions the lens off the board creating of axis tilts
·
Like base tilts – it requires refocusing after tilting
·
And increased weight (not if you use one for several
lenses)
Need a Shutter? We
carry a selection of well cared for classic shutters from ilex, Alphax and
Compur in sizes 00, 0, 1, 3, 4, & 5 as well as some as new Copal 0 and 1
shutters. Copal 3 shutters are normally available as well. A measurement of the
barrel diameter would help narrow down what size shutter you will need. To be
able to recommend the smallest size possible it is always best to have the lens
in hand but I will do my best to help you select a shutter. Being a field
photographer myself, size and weight are always an issue and I try to keep them
to a minimum when custom mounting lenses into shutters. All the
shutters we sell with the exception of the as new Copals have been serviced (a
$100.00 value). The prices are as follows (with some exceptions). For more
information on shutters made by ilex, Compur, Alphax, Copal and others please
see our “shutters” page.