Suspicious light leaks with an unknown cause

[JordanF]

Hi all,

Have been shooting for a while now and just as everything was going well on my large format journey I have had all 4 frames from a recent outing come back with varying degrees of light leaks :mad:

The images were shot from two holders I have used a few times before without issue on my Chamonix 45N-2 with a 150mm Fujinon lens. The sun was quite bright that day though the images of the statue were shot in shade.

I have previously suspected not pulling the darkslide smoothly to be the cause of a leak so I try to be pretty careful.

All the images were shot on FP4. I have been storing the film in the fridge and I did note that when loading the holders the film was sticking together a little bit - maybe I didn't let it acclimatise to room temperature enough before loading. Could this sticking together a little damage the emulsion enough to cause something like this?

I have been processing my film in a Stearman SP-445 which holds 4 negatives at a time. All 4 images were processed at once (as I am yet to learn about custom dev times for highlights etc). To anybody that uses this system, could the leaks be caused by a light leak in the tank?

I find the leak in the final shot of the building pretty interesting. It's almost like its in a perfect rectangle shape leaving two strips up the side of the frame....


Any ideas would be greatly appreciated :)

[David Lobato]

The bottoms of your images are the tops of the film holders, so sunlight is coming in via a gap. Check to make sure the film holders are fully seated and, if there is a bail lever on the back that it's closed, before you pull the dark slides. There could be warpage or something to cause gaps inside your film holders. Use a flashlight, shine the light down as in the position of overhead sun, and look for leaks through the open front standard. Do the same with each film holder between the dark slide and its slot.

[JordanF]

Thanks David, will try do a flash light check of the holders in the morning - though find it a bit odd that the leak happened on all 4 shots. Especially seeing as I had used the holders before without issues.

[andrewch59]

What David said, its a pain on a bright sunny day, I took the advice of someone on the forum and now ensure my dark cloth is over the film holder before removing the slide

[Dhuiting]

What David said, its a pain on a bright sunny day, I took the advice of someone on the forum and now ensure my dark cloth is over the film holder before removing the slide

I’ve had leaks like this (although not all four in an outing, that’s awful frustrating!) and I have to echo the previous sentiment about pulling the dark slide under the dark cloth. (I have the BTZS dark cloth and I like it a lot, and it has plenty of room to pull the slide without the sun hitting it.)

Since I implemented this rule (while sometimes awkward on 8x10) I’ve yet to have a light leak since. Perhaps something for you to try at least.


Sent from my iPhone using Tapatalk

[Vaughn]

Be careful not to pull back the darkslide a little as you draw it upwards.

[Doremus Scudder]

I concur with everything said already. I've had this problem when waiting around a long time after pulling the slide and shooting. It seems that the light traps leak a bit and, especially on sunny days, direct sun on the light trap gives us all problems, which gets worse the longer you have the slide out.

Leaving the dark cloth draped over the camera back and holder is a good solution, but impractical when windy or not using a darkcloth at all (which I do a lot in the field. I'll often use my hat/cap to shield the holder. If I know I'm going to be waiting for a while, I'll pull out my nifty homemade lightproof cover (made from cut-up and taped-together bottoms of sheet film boxes) that just fits over the slide end of a holder.

And, as Vaughn says, be careful to pull/insert the slide straight up and pinch the spring back to the camera body with the other hand while pulling/inserting the slide to prevent leaks

Best,

Doremus

[Bill Poole]

You can also use the dark slide itself to shade the top of the holder from the direct sun while you're making the exposure. (This does not provide as much security as the dark cloth or Doremus' solutions, of course.) Depending on your tripod head, you may have room to position the back with the opening facing down, out of the direct sunlight.

[Doremus Scudder]

You can also use the dark slide itself to shade the top of the holder from the direct sun while you're making the exposure. (This does not provide as much security as the dark cloth or Doremus' solutions, of course.) Depending on your tripod head, you may have room to position the back with the opening facing down, out of the direct sunlight.

Bill,

Of course you can use the darkslide too. I do it all the time, even balancing it on top of the holder/camera back for vertical shots sometime (even though a little wind will knock it off...). However, I'm usually using my darkslide to shade the lens, so the hat trick works well :)

Best,

Doremus

[Jim Noel]

ALWAYS leave your dark cloth over the camera to prevent such leaks. I learned long ago from Cole Weston to never let the film holders be in bright light. Take them from the carrying device under the dark cloth, slide them in the camera still covered,and finally keep the cloth over the camera. Also, get rid of that tiny little handkerchief you call a dark cloth. For a 4x5" camera, use a 4x5 foot cloth, or larger.

[Merg Ross]

ALWAYS leave your dark cloth over the camera to prevent such leaks. I learned long ago from Cole Weston to never let the film holders be in bright light. Take them from the carrying device under the dark cloth, slide them in the camera still covered,and finally keep the cloth over the camera. Also, get rid of that tiny little handkerchief you call a dark cloth. For a 4x5" camera, use a 4x5 foot cloth, or larger.

ALWAYS!

Excellent advice.

[Corran]

If you must have a large darkcloth thrown over the camera/back, it's my opinion the camera or holders are simply broken. I use a little black windbreaker jacket for a darkcloth on my 4x5 and don't do anything during exposure with it. I've had light leaks on my big 8x20, even with a big darkcloth thrown over it - because a darkcloth is not a darkroom and light can still get around it, especially when pulling the darkslide. Better to have a working camera, than a hope and a prayer about whether or not you'll have light leaks. But that's just my opinion, whatever works, works.

[LabRat]

I'll add to move holders to under darkcloth/camera in a pouch case (like a laptop pouch cover, pouch case, etc) so when you remove a holder from the stack with the others (in the shade nearby), you keep it from direct sunlight inside it, and remove it when it's ready to slide in (under darkcloth)...

I like the ones made of wet suit neoprene, as they can roll up or collapse when storing, and offer some padding...

Steve K

[andrewch59]

well added Steve, mine are in a small padded wine cooler bag which fits about ten holders, stops the film warming up and buckling in the heat