Konica T4 light leak?

runswithsizzers · Oct 13, 2022

I had my Konica Autoreflex T4 professionally serviced: new seals, CLA, battery circuit updated, new leather. Yesterday, I developed the first roll after the camera was serviced, and it looks like I still have a light leak. I would like to try to fix this myself, but I am not sure what kind of material needs to be put where.

In a previous post <here> I learned the most likely location of the leak is near the bottom of the door hinge. Should I start with the foam which is parallel to the hinge? - or is it more likely to be that thin strip in the channel that runs along the bottom of the door opening? Or somewhere else?

Thank you to anyone who can suggest the best way to isolate and repair this issue.

xkaes · Oct 13, 2022

If you have a magnifying glass -- which will help -- look at all of the foam and search for missing or thin spots. They obviously did a lousy job. If a thin/missing spot is not obvious, make sure that the door is not bent or twisted in some way. If you find a missing/thin spot, it's best to fill it with similar dark foam -- there are lots of sellers on EBAY. I'd demand a REDO, but that's just me.

Paul Howell · Oct 13, 2022

I would send it back, you paid for job that was not done right, and I would try and they the tech to pay for postage if you had it sent out of town.

BobD · Oct 13, 2022

Normally, you find the leak by inspecting the negative keeping in mind that the lens inverts and reverses the image onto the film.

MattKing · Oct 13, 2022

Take some electrical tape and sequentially cover each edge or portion of the edge of the back - top right, top centre, top left, hinge side, bottom right, bottom centre, bottom left, latch side - and for each location take 3 or four frames, making sure that the camera is subject to intense light from different angles and directions for each frame.
When not taking photos, keep the camera from the light. This may be easiest if you work inside, and use flash tio both expose the film and illuminate the camera.
Be sure to note which pictures were taken for each position of the tape!
Develop the film, and see if you can pin down where the leak is coming from - it will be the tape location where there isn't any leak..
If not, it may be a leak through the viewing system.

runswithsizzers · Oct 13, 2022

xkaes said:
If you have a magnifying glass -- which will help -- look at all of the foam and search for missing or thin spots. They obviously did a lousy job. If a thin/missing spot is not obvious, make sure that the door is not bent or twisted in some way. If you find a missing/thin spot, it's best to fill it with similar dark foam -- there are lots of sellers on EBAY. I'd demand a REDO, but that's just me.

Thank you. I will examine the seals more carefully when I finish this roll.

When got the camera, there was little or no foam in the gaps. I ordered a seal kit, but my first-ever foam seal installation did not go well. I wanted the meter circuit modified for modern batteries, so I figured I'd let a pro redo my shoddy job at the same time. The funny thing is, after I got the camera back from the pro, the light leak looks exactly like it did before; same spot, same pattern. This puzzles me.

Some possible explainations:
1. The pro did not replace the seals that I had previously installed
2. The pro did replace the seals, but there is some physical distortion in the body or the door that is preventing the seals from working.
3. The light is getting in by some path that is not blocked by properly installed seals.

As for a redo, it is complicated. I paid what seemed to me like a professional price for this service, and normally I would not hesitate to send it back. But in this case, the repair person is having some medical issues which caused my repair to take longer than expected (compounded by some other complications). He was scheduled for heart surgery a few days after he completed my repair. So I am trying to avoid two things: 1. I don't want to pressure someone who is recovering from surgery to go back to work before they are ready, and, 2. I don't want to be without the camera for another extended period of time, which seems likley if his medical issues continue.

edit: I have sent the service tech an email which he should see when feels like it.

MattKing · Oct 13, 2022

You may find that if you have and use the lower part of the (n)ever-ready case that was probably sold with the camera most if not all of the light leak issues would go away

runswithsizzers · Oct 13, 2022

MattKing said:
Take some electrical tape and sequentially cover each edge or portion of the edge of the back - top right, top centre, top left, hinge side, bottom right, bottom centre, bottom left, latch side - and for each location take 3 or four frames, making sure that the camera is subject to intense light from different angles and directions for each frame.
When not taking photos, keep the camera from the light. This may be easiest if you work inside, and use flash tio both expose the film and illuminate the camera.
Be sure to note which pictures were taken for each position of the tape!
Develop the film, and see if you can pin down where the leak is coming from - it will be the tape location where there isn't any leak..
If not, it may be a leak through the viewing system.

Great minds, and all that...

After I posted this morning, this same test occurred to me. So I put a roll of black electrical tape in my camera bag before I went out on photo walk-about. I managed to shoot half a roll before strong winds made me give it up. Since I am taking notes anyway, it is not much extra trouble to mark which frames were shot with the tape where.

Unfortunately, this roll of film is C-41, which I need to send-out for processing - so there will be some delay before I will see the results.

runswithsizzers · Oct 13, 2022

MattKing said:
You may find that if you have and use the lower part of the (n)ever-ready case that was probably sold with the camera most if not all of the light leak issues would go away

Not really my style. I mean, the leaks are not that bad. ;-)

albada · Oct 13, 2022

Here's a good way to narrow the cause down:
Examine the first and last negatives having the fogging, and see whether the horizontal position of the fog has shifted a little between the first/last frames. If the position has shifted, then film is being fogged while it's on the take-up spool. As the spool fills, the diameter of the film on it increases, shifting the fog position.
If there's a shift, the leak is probably at the hinge seal.
Otherwise, the leak is probably at the lower back seal.

runswithsizzers · Oct 13, 2022

albada said:
Here's a good way to narrow the cause down:
Examine the first and last negatives having the fogging, and see whether the horizontal position of the fog has shifted a little between the first/last frames. If the position has shifted, then film is being fogged while it's on the take-up spool. As the spool fills, the diameter of the film on it increases, shifting the fog position.
If there's a shift, the leak is probably at the hinge seal.
Otherwise, the leak is probably at the lower back seal.

Thank you. I probably never would have thought of that.

At the first occurance in frame two, I measure about 7.3-7.4 mm from the left edge of the frame to the start of the light mark. Frame 34 shows the last clear example, measuring 9.0 mm. So the distance does increase, but not by a whole lot.

As mentioned in #8, I am shooting some frames with tape over the hinge and others with tape over the bottom edge of the door; I'll know more when I see those results. Meanwhile, I guess I need to track down a source of suitable sealing material for the hinge area.

albada · Oct 13, 2022

runswithsizzers said:
At the first occurance in frame two, I measure about 7.3-7.4 mm from the left edge of the frame to the start of the light mark. Frame 34 shows the last clear example, measuring 9.0 mm. So the distance does increase, but not by a whole lot.
As mentioned in #8, I am shooting some frames with tape over the hinge and others with tape over the bottom edge of the door; I'll know more when I see those results. Meanwhile, I guess I need to track down a source of suitable sealing material for the hinge area.

In your first thread, folks suggested that the leak is at the lower hinge, and your measurements suggest they were correct.
You can search for "foam sheet self adhesive" online. Kids use them for crafts. Here's an example from Wal-Mart:

Uxcell Colorful EVA Foam Sheets Self Adhesive 7.8 x 11.8 Inch 1.8mm Thickness for Crafts DIY, 1 Set

Jon Goodman (jon_goodman@yahoo.com) sold many foam kits on eBay until he was burned. But he kept selling them to any who heard about him. He might still be in this business; it's worth asking.

MattKing · Oct 13, 2022

Last time I checked, jon_goodman@yahoo.com

runswithsizzers · Oct 14, 2022

I am hoping to fix the light leak by replacing only the foam next to the hinge. If so, I won't need a whole kit. Before I order a sheet of foam, I just need to figure out what thickness and what material I need.

Per the recommendation by albada in post #12, it sounds like EVA foam in 1.8mm thickness should work for my Konica T4? Or was that intended as a general example, not specific to my camera?

Before I sent the camera off for repairs I tried to install a kit I got from Gray at <USCamera> I notice he is promoting the use of <polyurethane foam> Should I care whether I buy EVA foam or polyurethene?

I also notice USCamera offers their polyurethane foam in thickness of: 1.0 mm - 1.5mm - 2.0 mm - 3.0 mm. Apparently, the kit they sell for my Konica T4 is all 1.0 mm thick. How critcal is the thickness?

I have emailed Jon Goodman; thanks for that recommendation - and thanks to MattKing for the email address!

albada · Oct 14, 2022

runswithsizzers said:
Per the recommendation by albada in post #12, it sounds like EVA foam in 1.8mm thickness should work for my Konica T4? Or was that intended as a general example, not specific to my camera?

That was a general example that might work on a hinge. I have noticed that SLR hinges close nearly flush, with almost no space between the two metal parts. That suggests using 1 mm foam at the hinge. You might be able to use thicker foam if it compresses without putting excessive force on the hinge. Here's a way to determine thickness: Scrape off a little foam near the bottom of your hinge, put a moist breadcrumb there, close the back and re-open it, and see how thin the breadcrumb was compressed. Play-dough or similar would work as well or better than a breadcrumb.

runswithsizzers said:
Before I sent the camera off for repairs I tried to install a kit I got from Gray at <USCamera> I notice he is promoting the use of <polyurethane foam> Should I care whether I buy EVA foam or polyurethene?

Original foam in most cameras is turning into tar. I thought that stuff is polyurethane, but perhaps not. Anyway, longevity makes me concerned about polyurethane. Does anyone know what decaying OEM foam is made out of?

Jon Goodman is honest and competent. If he's still in this business, I suggest buying from him.

runswithsizzers · Oct 14, 2022

albada said:
That was a general example that might work on a hinge. I have noticed that SLR hinges close nearly flush, with almost no space between the two metal parts. That suggests using 1 mm foam at the hinge. You might be able to use thicker foam if it compresses without putting excessive force on the hinge. Here's a way to determine thickness: Scrape off a little foam near the bottom of your hinge, put a moist breadcrumb there, close the back and re-open it, and see how thin the breadcrumb was compressed. Play-dough or similar would work as well or better than a breadcrumb.

Original foam in most cameras is turning into tar. I thought that stuff is polyurethane, but perhaps not. Anyway, longevity makes me concerned about polyurethane. Does anyone know what decaying OEM foam is made out of?

Jon Goodman is honest and competent. If he's still in this business, I suggest buying from him.

Jon Goodman answered my email inquiry promptly. I just ordered a seal kit for my camera from him. Hopefully the door hinge strip is all I'll need - but if not, I'll have the other seals on hand.

runswithsizzers · Jan 14, 2023

I still have not found the source of this light leak.

Apparently, it is not as simple as leak the foam light seals around the door / hinge. The same marks at the sprocket holes appear, even after I have applied black electrical tape all the way around the door, and the viewfinder, too.

I sent the Konica T4 back to the repair person about 6 weeks ago, but so far, still waiting for a solution.

Dan Daniel · Jan 14, 2023

Ask your repair person to look at the bottom plate of the camera. Remove it and study the bottom area. Check the tripod mount for cracks. Rewind button (if it has one) for proper mounting and sealing if appropriate. Battery compartment if there is one. Study the sprocket roller assembly and its mounting on the bottom inside the plate. Proper screws all around (no leaks). Some bottom plates have seals in places. Well, just something else to look at that I don't see mentioned above.

250swb · Jan 15, 2023

runswithsizzers said:
I still have not found the source of this light leak.

Apparently, it is not as simple as leak the foam light seals around the door / hinge. The same marks at the sprocket holes appear, even after I have applied black electrical tape all the way around the door, and the viewfinder, too.

I sent the Konica T4 back to the repair person about 6 weeks ago, but so far, still waiting for a solution.

Here is a link to the T4 light seal guide

https://uscamera.com/konica-auto-reflex-t4-tc-placement-guide/

if you'd have got a light seal kit you'd have seen which ones need replacing. My guess is the repair person missed a seal or didn't spot the one that had degraded.

bernard_L · Jan 15, 2023

In case camera comes back from repair still with problem.
Put your camera on a table, back open, lens down. Place the negative on the rails aligned with the image window (proeprly reversed). The leak imprint on the negative will point to the location of the light leak. Three possible locations: across image window, offset one frame towards supply cartridge, offset one frame towards take-up spool.

Konica T4 light leak?

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