Pentax 645N light leak

[photogear]

Just acquired a Pentax 645N. On the first roll, I see 6 shots with a light leak (out of 15).
There might be several reasons but what makes me annoyed is the difficulty to find out in my area a tech that could fix the problem.
Picture enclosed.

 

[photogear]

 

[pentaxuser]

Do all 5 other affected frames exhibit exactly the same arrow straight line as you show and what are the frame numbers?

Just to add, the 645N should take 16 frames

pentaxuser

 

[photogear]

same patterns on all 6 shots although. the "intensity" isn't quite the same.
sorry there might have been a blank shot on this first roll...

 

[ant!]

Renew the foam light seals in the film insert, or at least check them? Other the those: I forgot if the shutter runs horizontal or vertical?
At least camera wise, not sure where else light could leak...

 

[MFstooges]

looks like same problem as this thread

Pentax 645N shutter lines on negatives

Hi, I have a 645n which has developed this problem, which appears common: http://www.pentaxforums.com/forums/48-pentax-medium-format/174550-lines-645n-negatives.html Presumably a curtain is sticking and causing the uneven exposure. It happens randomly every so often. Any hints? Tom

www.photrio.com

 

[reddesert]

Please post a picture of the entire frame including the area outside the image (all the way to the edge of the film). This is important to diagnose where the light leak is coming from - whether the leak stops at the frame edge, or continues into the rebate.

 

[RalphLambrecht]

Just acquired a Pentax 645N. On the first roll, I see 6 shots with a light leak (out of 15).
There might be several reasons but what makes me annoyed is the difficulty to find out in my area a tech that could fix the problem.
Picture enclosed.

Qualified technicians are getting rare everywhere. I wish some would embrace the craft; there is a market niche.

 

[MFstooges]

Qualified technicians are getting rare everywhere. I wish some would embrace the craft; there is a market niche.

It's tough to sell service where the object is decreasing in $$$ and labor cost is only increasing.

 

[RalphLambrecht]

It's tough to sell service where the object is decreasing in $$$ and labor cost is only increasing.

true but supply is low and demand is high and increasing.

 

[loccdor]

Make sure you have continuous light seals on the back/door. My Mamiya 645 had a light leak when I got it, It was caused by the shiny metal latch for the door not having foam behind it, the light would reflect off the shiny metal and into the camera.

It's easy to check where it is on most cameras with a flashlight, dark room, lens off, leaving the shutter open in bulb mode.

I was intimidated at replacing foam myself at first but it really is something that anybody can do.

 

[ant!]

Make sure you have continuous light seals on the back/door. My Mamiya 645 had a light leak when I got it, It was caused by the shiny metal latch for the door not having foam behind it, the light would reflect off the shiny metal and into the camera.

It's easy to check where it is on most cameras with a flashlight, dark room, lens off, leaving the shutter open in bulb mode.

I was intimidated at replacing foam myself at first but it really is something that anybody can do.

The Pentax 645 has film inserts with light seals, no door otherwise, and I wouldn't know where a leak elsewhere could be (beside a shutter issue)

 

[pentaxuser]

same patterns on all 6 shots although. the "intensity" isn't quite the same.
sorry there might have been a blank shot on this first roll...

What I was trying to find out is were all 6 affected frames in sequence i.e. 1-6; 2-7; 3-8 etc or does it occur at random intervals

The effect in your example appears to be identical to one of the negatives linked to in another thread that was on Pentax Forums

My insert appears on close examination to have a black seal which is tailor-made for the insert It looks to be a form of thin rubber-like material. I mention close examination as the seal is not that obvious unless you look closely at the insert

What I cannot work out is why a damaged or missing seal would produce the effect of a straight line. So straight in fact that it is as if it was done using a straight edged ruler

There was an answer on a previous thread that a light leak from a faulty seal threw a shadow onto part of the negative that was on the receiving spool after the neg's exposure but I wasn't clear if produced the same kind of a straight line

pentaxuser

 

[choiliefan]

If Eric Hendrickson is still doing repairs, he's your man, without a doubt.

 

[photogear]

thx for so many replies
to reddesert: the line goes all across the frame: i could not download the whole shot coz there was a pixel limit
to RalphLambrecht: I have a local retired tech who is willing to take a look at the camera later on. Obviously I can't wait that long but I have no choice.
to MFstooges: years ago I made almost a promise to myself as not to buy a format 120 for the repair is difficult to find (parts and tech) and for some reasons I could not resist the Pentax 645N...
to loccdor: I will check it out somehow
to antl: I am not sure I understand. Beside the shutter issue, I was told there could be an issue with the back of the camera...
to pentaxuser: after reviewing the negatives, there are 4 shots with light leaks (sorry for the mistake) and the sequence is as the following: 01-03-07-09. Yes I will check the seal out.
to choiliefan: I have been in touch with Hendrickson in the past. Of course, he's my second option after the local tech.

 

[MattKing]

If you want to download something large, resize it first to 1000 pixels on the longest side.
When we talk about the "back" on these cameras, we are essentially talking about where the film loader/insert meets up with the camera body.
The red highlight is poorly drawn, but my addition to this graphic from the manual should give you an idea of what we mean:

 

[photogear]

hopefully you get a view of the foam camera at rest

 

[photogear]

here's the camera on B position.

 

[photogear]

THX Matt for the pixel limite

 

[reddesert]

thx for so many replies
to reddesert: the line goes all across the frame: i could not download the whole shot coz there was a pixel limit

Resize the image before uploading. It doesn't need to have full fine detail. Even a phone camera shot of the negative held against a light is useful.

The question is whether the line of over density continues outside the image area and into the rebate (unexposed edge of the film). If there is a light leak into the rebate, it tells you the problem is behind the film gate - if so, for example, it could be a light leak at the closure of the back, but not a shutter problem.

 

[Eff64]

Just acquired a Pentax 645N. On the first roll, I see 6 shots with a light leak (out of 15).
There might be several reasons but what makes me annoyed is the difficulty to find out in my area a tech that could fix the problem.
Picture enclosed.

Without knowing how the shutter travels on that one, my bet is on the shutter being the problem. Normally a light leak (from seals or otherwise) will have a somewhat random shape, irregular density (within the leak area) and just generally a crazy looking pattern.

Your’s is very straight, across the whole frame (as others have commented, it would help to see the edge
of the film outside the live area) and within that lighter area, although I see some variation, it is hard to tell how much of that was actually the subject lighting.

Have you tried removing the film insert and dry firing so you can observe what the shutter is doing? That doesn’t always reveal anything, but it is easy enough to do just in case.

At minimum I would inquire about returning it for a refund. There are plenty of these for sale and instead of going the repair route with an unknown repair person, maybe just side step the whole thing?

 

[Eff64]

One more thing, just noticing your photos of the mirror box showing foam. It would be very unusual to have a light leak through the lens mount. 1-there is no foam between the body/lens 2-lenses don’t leak light, they could only create flare in certain conditions, and this doesn’t look like that.

People who have mentioned seals are talking about where the film insert fits and locks into the body, which you didn’t include in those photos.

 

[photogear]

Without knowing how the shutter travels on that one, my bet is on the shutter being the problem. Normally a light leak (from seals or otherwise) will have a somewhat random shape, irregular density (within the leak area) and just generally a crazy looking pattern.

Your’s is very straight, across the whole frame (as others have commented, it would help to see the edge
of the film outside the live area) and within that lighter area, although I see some variation, it is hard to tell how much of that was actually the subject lighting.

Have you tried removing the film insert and dry firing so you can observe what the shutter is doing? That doesn’t always reveal anything, but it is easy enough to do just in case.

At minimum I would inquire about returning it for a refund. There are plenty of these for sale and instead of going the repair route with an unknown repair person, maybe just side step the whole thing?

the line is going across the picture and the whole negative altogether.
talking with the seller as to return it but I want to get it checked out by a local tech
dry firing doesn't reveal something out of the ordinary

 

[OAPOli]

Most likely a leak in the film holder frame. Inspect and replace the foam seals there.

Lines On 645N Negatives - PentaxForums.com

Hi, Does anyone have ideas as to what could be causing lines to appear on my P645N negatives? (These were home developed and scanned with an Epson

www.pentaxforums.com

 

[pentaxuser]

What seems strange to me about the answer being a light leak through the insert and the accompanying diagram showing it, is why in the OP's case the leak isn't casting a shadow line across every frame when the light leak through the insert hits every negative as it is wound on to the receiving spool

pentaxuser