Linhof Technika V - Ground Glass is Dim.

[stephenmcateer]

I recently acquired a 1972 year model Technika V.

I'm finding the ground glass to be pretty dim.

Are more recent Technika ground glasses brighter?

Would I be able to fit one myself?

Thanks for any advice.

[Bob Salomon]

The current one is much brighter and is easy to fit.

[stephenmcateer]

Great. Thanks Bob.

[David Lindquist]

Is see Linhof & Studio has these in stock. Since you ask for advice, here's my thoughts for what they are worth: There are two styles, one is "multi-format"; in addition to a grid of 1 cm squares it has outlines for 6 x 7, 6 x 9 and 6 x 12 cm. If you think you might use any of those three formats in addition to 4 x 5 then I expect you would want that one. I don't use any of those three formats and personally find their presence makes the ground glass a bit "busy." So I like the simpler version that just has the 1 cm grid.

David

[stephenmcateer]

Is see Linhof & Studio has these in stock. Since you ask for advice, here's my thoughts for what they are worth: There are two styles, one is "multi-format"; in addition to a grid of 1 cm squares it has outlines for 6 x 7, 6 x 9 and 6 x 12 cm. If you think you might use any of those three formats in addition to 4 x 5 then I expect you would want that one. I don't use any of those three formats and personally find their presence makes the ground glass a bit "busy." So I like the simpler version that just has the 1 cm grid.

David

Thanks David. The markings on the ground glass are something I was thinking about: I like as few markings as possible so I'll probaby go for the simple grid. [6x12 interests me but if I ever get a 6x12 back I can always get the correct glass for it — they're not hugely expensive.]

[Tin Can]

Try washing the GG

Most are filthy and dim

Grind does make a difference, my 1950's OE studio 4X5 Linhof has very coarse grind

but it has uses too

[stephenmcateer]

Try washing the GG

Most are filthy and dim

Grind does make a difference, my 1950's OE studio 4X5 Linhof has very coarse grind

but it has uses too

Thanks. Hadn't thought of that. I bought a new glass from Linhof. I believe it should improve things quite a bit.

[LabRat]

Whatever you try, carefully note the orientation of GG + fresnel surfaces as you remove the old to make sure they are reassembled correctly, or a focusing error can be introduced...

If you wash GG, it will wash off lines on it, but I just draw in new ones with a hard lead pencil + drawing/measuring instruments...

Steve K

[Greg]

Years ago the GG on my 11x14 Burke & James view camera was also "dim". Took the GG out and very, very lightly scrubbed it with a very soft brush in a diluted Ivory soap solution. Rinsed it several times under the tap, and then finally a few times with distilled water. Dried it slowly using a hand held drier. I swear after doing this, the GG was X2 times brighter. Used the same posted procedure for cleaning a front surfaced telescope's mirror... Google it.

[stephenmcateer]

Whatever you try, carefully note the orientation of GG + fresnel surfaces as you remove the old to make sure they are reassembled correctly, or a focusing error can be introduced...

If you wash GG, it will wash off lines on it, but I just draw in new ones with a hard lead pencil + drawing/measuring instruments...

Steve K

Okay thanks. I looked at the hardware that secures the glass — 6 screws, a couple of plates and I think some shims. Hopefully fitting the new one won't be too difficult. I may put the old one on eBay to recoup some of the cost of the new one.

[stephenmcateer]

Years ago the GG on my 11x14 Burke & James view camera was also "dim". Took the GG out and very, very lightly scrubbed it with a very soft brush in a diluted Ivory soap solution. Rinsed it several times under the tap, and then finally a few times with distilled water. Dried it slowly using a hand held drier. I swear after doing this, the GG was X2 times brighter. Used the same posted procedure for cleaning a front surfaced telescope's mirror... Google it.

Thanks Greg. I suppose I should have tried cleaning the glass before I bought the new one. Live and learn…

[Bob Salomon]

Okay thanks. I looked at the hardware that secures the glass — 6 screws, a couple of plates and I think some shims. Hopefully fitting the new one won't be too difficult. I may put the old one on eBay to recoup some of the cost of the new one.

The way I do it is to remove the three screws and the plate at one end, note that sometimes the center,screw may be longer.
Loosen the 3 screws on the other end.
Lift the gg up and slide it out from the other end.
Place the new gg in place on the shims.
Replace the plate and tighten all screws.

[stephenmcateer]

The way I do it is to remove the three screws and the plate at one end, note that sometimes the center,screw may be longer.
Loosen the 3 screws on the other end.
Lift the gg up and slide it out from the other end.
Place the new gg in place on the shims.
Replace the plate and tighten all screws.

Thanks Bob. The glass should be here in a few days. Looking forward to more brightness.

[stephenmcateer]

UPDATE: I have the ground glass now. It looks nice.
However, I couldn't loosen the screws that are holding the original glass in place: the screwheads are about 5mm wide but the slot is very narrow — less than a millimetre I think, so a normal screwdriver won't do.
I purchased a 3mm precision screwdriver, thinking it ought to be wide enough to let me exert enough force to undo the screws but I'm wondering if they're a little seized in the threads: the 3mm driver cammed out on the first screw I tried, so I stopped there.
[I couldn't see a suitable screwdriver online despite searching for quite a while, so if anyone can recommend one suitable for this task I'd be obliged.]

[Conrad . Marvin]

A proper screwdriver should be the same width as the screw head and the same thickness as the slot width. If it is too wedge shaped, it will push up out of the slot and and make the screw useless. Time to get a machinist to make you a correct size screwdriver out of something a bit too big. It should be worth the cost.

[LabRat]

A screw can freeze in a hole as many changes of weather force moisture into threads causing local corrosion in hole... Getting a tiny drop of thread penetrating oil near base of threads, let sit a couple of days, repeat, taking a hot soldering iron and heating up head with tip a few times and allowing it to cool, then try...

A good screwdriver to try is made by Wiha, good tip that should fit exactly, and has a larger handle that has good torque, and not expensive for a single... Don't use a cheap driver, as you are more likely to damage screw head with one...

Good luck!!!

Steve K

[stephenmcateer]

A proper screwdriver should be the same width as the screw head and the same thickness as the slot width. If it is too wedge shaped, it will push up out of the slot and and make the screw useless. Time to get a machinist to make you a correct size screwdriver out of something a bit too big. It should be worth the cost.

Thanks. The drivers I have are too narrow / too thick in the blade. I don't know if there's a machine shop near here or not but I'll look.

[stephenmcateer]

A screw can freeze in a hole as many changes of weather force moisture into threads causing local corrosion in hole... Getting a tiny drop of thread penetrating oil near base of threads, let sit a couple of days, repeat, taking a hot soldering iron and heating up head with tip a few times and allowing it to cool, then try...

A good screwdriver to try is made by Wiha, good tip that should fit exactly, and has a larger handle that has good torque, and not expensive for a single... Don't use a cheap driver, as you are more likely to damage screw head with one...

Good luck!!!

Steve K

Thanks. Some good tips there. I'll look for Wiha.

[David Lindquist]

I got these to deal with those large diameter narrow slotted screws with which to my mind European makers of view cameras seem to be enamored: https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-bits/magna-tip-thin-bits-prod425.aspx

They are even described as being for "European style slots." These are hollow ground, in the US anyway this pattern of screwdriver tip is often called a "gunsmith's screwdriver". I don't know if Brownells ships to the UK, I expect that is some where in the fine print on their website.

I got the full set largely because I'm a tool weenie. You could scroll through the selection for the blade width(s) that you want, note that they say "blade diameter" instead of "blade width". As far as thickness, these come in .020 and .025 inch (.51 and .63 mm) thickness. I find the thicker ones are a very close fit bordering on a push fit in the screws holding the ground glass on my Master Technika 3000; the thinner goes in easily. If it were me, I'd get both thicknesses. But then I'm a tool weenie and I got the full set.

I have to wonder where Linhof and Linhof repair people get their screwdrivers.

Stand by while I track down the handle for these.

David

[David Lindquist]

Here are handles: https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-handles/magna-tip-super-set-screwdriver-handles-prod400.aspx

I use the #81, the #84 is hollow and holds up to to four bits.

Let us know if these work for you.

David

[stephenmcateer]

Here are handles: https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-handles/magna-tip-super-set-screwdriver-handles-prod400.aspx

I use the #81, the #84 is hollow and holds up to to four bits.

Let us know if these work for you.

David

Thanks David. Off to take a look…

[stephenmcateer]

I got these to deal with those large diameter narrow slotted screws with which to my mind European makers of view cameras seem to be enamored: https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/screwdrivers-sets/magna-tip-bits/magna-tip-thin-bits-prod425.aspx

They are even described as being for "European style slots." These are hollow ground, in the US anyway this pattern of screwdriver tip is often called a "gunsmith's screwdriver". I don't know if Brownells ships to the UK, I expect that is some where in the fine print on their website.

I got the full set largely because I'm a tool weenie. You could scroll through the selection for the blade width(s) that you want, note that they say "blade diameter" instead of "blade width". As far as thickness, these come in .020 and .025 inch (.51 and .63 mm) thickness. I find the thicker ones are a very close fit bordering on a push fit in the screws holding the ground glass on my Master Technika 3000; the thinner goes in easily. If it were me, I'd get both thicknesses. But then I'm a tool weenie and I got the full set.

I have to wonder where Linhof and Linhof repair people get their screwdrivers.

Stand by while I track down the handle for these.

David

Thanks again David. I mailed them to ask which driver would be best for this application. [They have a .co.uk website and it appears they import from the USA, which is fine with me.]

[Bernice Loui]

Tools for working on precision/precise instruments are serious considerations. Lesser tools will damage the instrument being worked on.

Metric (DIN/ISO/JIS) spec slotted screws do not have the same dimensions as Imperial aka US of A "fraction" based screws. They are NOT interchangeable and the tools used to work then must be of the same specifications/dimensions.

Best screwdrivers for slotted head screws have parallel tips. These are known as hollow ground in USA tool industry. The most common variety have a radii ending at the screwdriver tip. This design is inherently weaker due to the unsupported area between the body of the radii to the screwdriver tip.

The best slotted screwdrivers made are PB swiss. Their slotted screwdriver tip design over comes this problem by forging the parallel tip area to fit the slotted screw slot.
229603

This greatly reduces breakage of the screwdriver and transits most of the twisting torque to the screw slot instead of flexing. PB swiss uses as special steel for their screwdrivers. No idea what it is, just the set that has been used for decades has held up remarkably well.
https://www.pbswisstools.com/en/tools/quality-hand-tools/screwdrivers/product/pb-610000-70

Smaller slotted head screws are common in watch repair.. They have a different style of slotted screwdriver and they can be really small..
https://www.jewelerssupplies.com/screwdrivers-hollow-ground-concave-blades-0-6-2-0-520.766%200.6-2.0mm.html

None of these high quality tools are "low cost"..
https://www.jewelerssupplies.com/tools/screwdrivers.html

Ideally measure the screw slot width and diameter of the screw head to determine what size metric screw driver is needed for the specific slotted head screw.

Most common slotted drive metric screw is known as a cheese head..
https://fastenerengineering.com/what-are-cheese-head-screws/

~Most important to keep in mind, aluminum is very subject to corrosion. What often happens, aluminum internal screw threads can develop corrosion effectively "locking" the screw to the internal aluminum threads. The torque required to remove the screw can snap off the screw head leaving a serious mess of a broken screw in the aluminum part. If the screw is stuck, DO soak the stuck screw in penetrating oil for a day or more before trying to remove the screw. If the screw breaks off, it will ruin a lot more than just that day.~


Bernice

[David Lindquist]

Thanks again David. I mailed them to ask which driver would be best for this application. [They have a .co.uk website and it appears they import from the USA, which is fine with me.]

Good, it sounds like these are going to be easy enough to buy.

David

[stephenmcateer]

Tools for working on precision/precise instruments are serious considerations. Lesser tools will damage the instrument being worked on.

Metric (DIN/ISO/JIS) spec slotted screws do not have the same dimensions as Imperial aka US of A "fraction" based screws. They are NOT interchangeable and the tools used to work then must be of the same specifications/dimensions.

Best screwdrivers for slotted head screws have parallel tips. These are known as hollow ground in USA tool industry. The most common variety have a radii ending at the screwdriver tip. This design is inherently weaker due to the unsupported area between the body of the radii to the screwdriver tip.

The best slotted screwdrivers made are PB swiss. Their slotted screwdriver tip design over comes this problem by forging the parallel tip area to fit the slotted screw slot.
229603

This greatly reduces breakage of the screwdriver and transits most of the twisting torque to the screw slot instead of flexing. PB swiss uses as special steel for their screwdrivers. No idea what it is, just the set that has been used for decades has held up remarkably well.
https://www.pbswisstools.com/en/tools/quality-hand-tools/screwdrivers/product/pb-610000-70

Smaller slotted head screws are common in watch repair.. They have a different style of slotted screwdriver and they can be really small..
https://www.jewelerssupplies.com/screwdrivers-hollow-ground-concave-blades-0-6-2-0-520.766%200.6-2.0mm.html

None of these high quality tools are "low cost"..
https://www.jewelerssupplies.com/tools/screwdrivers.html

Ideally measure the screw slot width and diameter of the screw head to determine what size metric screw driver is needed for the specific slotted head screw.

Most common slotted drive metric screw is known as a cheese head..
https://fastenerengineering.com/what-are-cheese-head-screws/

~Most important to keep in mind, aluminum is very subject to corrosion. What often happens, aluminum internal screw threads can develop corrosion effectively "locking" the screw to the internal aluminum threads. The torque required to remove the screw can snap off the screw head leaving a serious mess of a broken screw in the aluminum part. If the screw is stuck, DO soak the stuck screw in penetrating oil for a day or more before trying to remove the screw. If the screw breaks off, it will ruin a lot more than just that day.~


Bernice

Thanks Bernice. This particular camera came from Japan — it has little areas of corrosion as though it has been stored for a long time. Nothing serious but I'm thinking these screws are probably, as you say, seized into the ground glass frame.

Actually, I'm not certain I want to get into high-torque attempts to get the screws out and possibly shearing off the heads. The ideal solution would be to send the camera to Linhof but £££… I have to think about this.

[Philippe Grunchec]

The ideal solution would be to send the camera to Linhof but £££… I have to think about this.
Send it to Munich, it will be €€€ instead of £££!

[Philippe Grunchec]

The ideal solution would be to send the camera to Linhof but £££… I have to think about this.
Send it to Munich, it will be €€€ instead of £££!

[Tin Can]

It is also easy to regrind almost any GG