Well I think we are there!
After a bit of filing, head scratching and much appreciated help from people at Robert White and Lee Filters, I have managed to successfully mount Lee Neutral Density filters on my Phase One 28mm lens. There is probably still some fine tuning to do, but all is looking good and I am looking forward to having the ability to control scene contrast with ND grads.
The solution involves a Lee FIlters 115mm push on holder, X-pro wings 2x4mm blades 2xStd (2mm) blades, 4x1inch screws (even longer would be better) and 4x3/8 screws plus a modified doughnut ring.
The Doughnut ring was the one I had for my Schneider IIIb centre filter and 58, 80 and 110 XL lenses. It has had the internal retaining lip hand-filed away and as you can see a very slight chamfer too to prevent scratching of the lens when putting the holder on the lens. In order to further prevent any scratching, I've put a single strip of black pvc insulating tape on the inside surface. The serrations visible in the photo is simply where my knife snagged.
The 4mm blades are really too wide and the filter slips down due to insufficient pressure/friction. I've added a lamination of 6 strips of pvc insulating tape to the arced pressure plates on each blade to decrease the slot width.
The photos show the holder attached to the lens in situ for 2 ND filters to be placed. You can see that the holder doesn't have full 360 deg contact, but is on all 4 petals of the fixed lens hood. It is plenty secure enough. For one filter obviously I can put it slightly further on the lens. Screws longer than 1 inch with extra blades would enable the holder to sit deeper still on the lens providing some extra spacers were fitted.
Invariably I am using the camera in low light and I want a simple placement system to be able to use with ease and confidence. My current solution is that for two filters, the doughnut ring sits halfway across the Phase One writing on the lens as can be seen in the photos.
I may well investigate having a thin foam stop strip taped around the outside of the lens which will allow the holder to be positively placed permitting the use of 2 ND filters so that they can be staggered. Thus when I want to fit the filter holder it will locate itself at the correct position without any risk of contact between ND filter and petal lens hood. This strip will also permit the use of the standard lens cap, albeit standing slightly proud.
I think this set-up using Lee equipment is more elegant than using a Cokin X-Pro holder with their universal screw adaptor. The latter item appears to be back ordered when I searched for it. The drawback of the Cokin system is that the holder is held in place by point pressure from nylon screws instead of the circular pressure plate that the Lee Push-on holder uses.
Currently I have bought two X-Pro sized filters a 0.3 and a 0.75 because of the limited availability. The 0.75 would not have been my first choice, but I figure that inverting the 0.3 with the 0.75 placed normally will provide the 0.45 I prefer for skies. I won't be able to stagger a 0.3 and 0.45 which is a combination I like to use for coastal shots. I'll see how things go before adding to the collection. The provided nylon pouches are oversized, so I've cut off the tops to enable them to fit easily in my Kata Bumblebee PL-220 bag.
There are absolutely no signs of cut-off in the viewfinder.
I'm leading a workshop this weekend and hope to give it all a shot.
After a bit of filing, head scratching and much appreciated help from people at Robert White and Lee Filters, I have managed to successfully mount Lee Neutral Density filters on my Phase One 28mm lens. There is probably still some fine tuning to do, but all is looking good and I am looking forward to having the ability to control scene contrast with ND grads.
The solution involves a Lee FIlters 115mm push on holder, X-pro wings 2x4mm blades 2xStd (2mm) blades, 4x1inch screws (even longer would be better) and 4x3/8 screws plus a modified doughnut ring.
The Doughnut ring was the one I had for my Schneider IIIb centre filter and 58, 80 and 110 XL lenses. It has had the internal retaining lip hand-filed away and as you can see a very slight chamfer too to prevent scratching of the lens when putting the holder on the lens. In order to further prevent any scratching, I've put a single strip of black pvc insulating tape on the inside surface. The serrations visible in the photo is simply where my knife snagged.
The 4mm blades are really too wide and the filter slips down due to insufficient pressure/friction. I've added a lamination of 6 strips of pvc insulating tape to the arced pressure plates on each blade to decrease the slot width.
The photos show the holder attached to the lens in situ for 2 ND filters to be placed. You can see that the holder doesn't have full 360 deg contact, but is on all 4 petals of the fixed lens hood. It is plenty secure enough. For one filter obviously I can put it slightly further on the lens. Screws longer than 1 inch with extra blades would enable the holder to sit deeper still on the lens providing some extra spacers were fitted.
Invariably I am using the camera in low light and I want a simple placement system to be able to use with ease and confidence. My current solution is that for two filters, the doughnut ring sits halfway across the Phase One writing on the lens as can be seen in the photos.
I may well investigate having a thin foam stop strip taped around the outside of the lens which will allow the holder to be positively placed permitting the use of 2 ND filters so that they can be staggered. Thus when I want to fit the filter holder it will locate itself at the correct position without any risk of contact between ND filter and petal lens hood. This strip will also permit the use of the standard lens cap, albeit standing slightly proud.
I think this set-up using Lee equipment is more elegant than using a Cokin X-Pro holder with their universal screw adaptor. The latter item appears to be back ordered when I searched for it. The drawback of the Cokin system is that the holder is held in place by point pressure from nylon screws instead of the circular pressure plate that the Lee Push-on holder uses.
Currently I have bought two X-Pro sized filters a 0.3 and a 0.75 because of the limited availability. The 0.75 would not have been my first choice, but I figure that inverting the 0.3 with the 0.75 placed normally will provide the 0.45 I prefer for skies. I won't be able to stagger a 0.3 and 0.45 which is a combination I like to use for coastal shots. I'll see how things go before adding to the collection. The provided nylon pouches are oversized, so I've cut off the tops to enable them to fit easily in my Kata Bumblebee PL-220 bag.
There are absolutely no signs of cut-off in the viewfinder.
I'm leading a workshop this weekend and hope to give it all a shot.