filter glass removal

sfphoto · May 5, 2021

AFAIK the filter glass is held in with a rolled rear rim.
There is no slotted retaining ring.
No rear springwire.

Thus I suspect to remove the glass, one would need to break it.

If some one here sees otherwise, kindly advise.

AgX · May 5, 2021

You could mill off or even turn off the retaining flange, but you then would need a metal workshop and some expertise.

A kitchen-table solution would be splitting the ring with a fret saw at least at one side and bending it open. But this needs expertise too.

sfphoto · May 5, 2021

Thanks for the response. Neither front nor back retainer would seem to be threaded. I idid try friction on the rear one.

After reading your post thought I might try to protect the glass w/ thick tape and hand drill a hole to part the inner rear ring.

shutterfinger · May 5, 2021

Soak the gap on the rear with Acetone/acetone based nail polish remover then try again. Some vintage lens cells were held in place by a rolled over edge of the brass housing. That type of mount is removed by lifting up the rolled over edge in small increments until the element can be removed.
I do not know what will work for your filter. I cannot tell if its folded over edge or sandwiched pieces bonded together.

AgX · May 5, 2021

If a filter pane is crimped into a filter-ring what use is the application of Acetone? I am clueless.
Or do I have to understand your last sentence as a hint to the possibiltiy of the pane being cemented into the ring?

mshchem · May 5, 2021

Looks pressed in??
I have taken Tiffen filters apart with a lens wrench. Two tiny "dimples" that take pin point bits in the wrench, easy to unscrew. If it's easy to get apart I suspect it would be apparent, unfortunate.
I absolutely will not use aluminum filter rings, too easy to cold weld.

sfphoto · May 5, 2021

It is quite a modern almost new filter.
Would think the rear ring is pressed in rather than cement and I doubt it is threaded.

I suspect acetone would be safe - perhaps though not if there is external coating.

The rim is the thinnest I have seen and wanted to swap out the glass w/ a UV as the UV I am using vignettes (much thicker rim).

AgX · May 5, 2021

The first two photos can show several ways of retaining:
-) a flange of the ring crimped-over the pane
-) a inner ring pressed into the outer ring
-) a inner ring cemented into the outer ring (and maybe to the pane)

AgX · May 5, 2021

Something else:
Why do you want to take off the pane?

sfphoto · May 5, 2021

AgX said:
The first two photos can show several ways of retaining:
-) a flange of the ring crimped-over the pane
-) a inner ring pressed into the outer ring
-) a inner ring cemented into the outer ring (and maybe to the pane)

All 3 of the same filter, just 2 different views of the rear side.

sfphoto · May 5, 2021

AgX said:
Something else:
Why do you want to take off the pane?

Wanted to swap out the glass

Dan Fromm · May 5, 2021

All that effort to avoid buying a thin 58 mm UV filter or a step-up ring and a larger UV filter? Sheesh!

Bill Burk · May 5, 2021

Actually 3.0 ND is a real useful filter. UV filters are not very rare in comparison.

sfphoto · May 5, 2021

Dan Fromm said:
All that effort to avoid buying a thin 58 mm UV filter or a step-up ring and a larger UV filter? Sheesh!

It is actually more complicated than that.
The intended lens has no filter provision (ultra WA).
I removed the glass from a 58 (4mm depth) and inserted into the fixed hood (prevents step up)
Then attached a thin (3mm) 58.
The corners are nicked.
So...
I want to replace the 4mm ring with a 3mm one and the only 3mm ones I have are w/o easy glass removal.

Dan Fromm · May 5, 2021

Have you considered a slip-on filter holder? Series holders, home brew, ... Or even duct tape.

Out of curiosity, what's the lens?

sfphoto · May 5, 2021

Dan Fromm said:
Have you considered a slip-on filter holder? Series holders, home brew, ... Or even duct tape.

Out of curiosity, what's the lens?

Will make a photo tomorrow and upload

Kodachromeguy · May 5, 2021

I don't understand. What will the UV filter do? Did the lens maker make any provision for filters, like drop-in or a turret?

Tel · May 6, 2021

If it were mine, I would do what AGX suggested: cut the ring with a small fret saw (jeweler's saw) or a small hacksaw by hand and very carefully, so as not to nick or crack the glass. Then pry the ring open and remove the glass. Since the glass is what you want to save, there's no advantage to preserving the metal ring.

sfphoto · May 6, 2021

Kodachromeguy said:
I don't understand. What will the UV filter do? Did the lens maker make any provision for filters, like drop-in or a turret?

No filter provision built in - there is a slip on 77mm filter adapter
This however is such a sweet small lens (63x62mm 290g - same specs as a Nikkor 85f2 AI lens) - putting a 77mm up front was not what I wanted.

Dusty/Sandy situations or Sea Spray call for a protective filter.

sfphoto · May 6, 2021

Tel said:
If it were mine, I would do what AGX suggested: cut the ring with a small fret saw (jeweler's saw) or a small hacksaw by hand and very carefully, so as not to nick or crack the glass. Then pry the ring open and remove the glass. Since the glass is what you want to save, there's no advantage to preserving the metal ring.

Thanks, exactly what I did today only I drilled a hole in the ring. In hindsight I could have notched the ring for a spanner as I found is actually was threaded.

sfphoto · May 6, 2021

So thanks to all for your comments and guidance.

The lens is a 7 Artisans 12/2.8 - 18mm EQ on APS digital sensor.
Terrific lens for under $200 for APS.
It renders like an older Leica Super Angulon, great saturation with falloff at the corners which draws ones attention to the center.
Excellent build (there is a tear down report on-line) that has distance scale and DOF markings.
One must though work around the field curvature and make sure the lens is centered (my 3rd purchase was centered).

Photo shows the above mentioned filter ring in place w/o glass.

ready to accept (slim) filters.

filter glass removal

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