4x10 sheet exposure gone wrong

[ediz7531]

I'm wondering if someone can shed light on what went wrong here. I just got a Chamonix 410 camera, which came with Chamonix-holders. I'm using FP4+ in 4x10 (not 8x10 cut in half).
This was a 3-minute exposure. I have a very sturdy RRS tripod, so I doubt it was camera shake. If you look closely along the top edge, it appears like the sheet shifted vertically (along the direction of gravity) sometime during the exposure. I'm certain when I loaded the film the sheet's edges went under the guide rails of the film holder - I tend to double check this usually.

 

[ediz7531]

I realized that rather than the sheet moving down, more likely is an issue with lens rise. I used a bit of lens rise on this frame. I guess I must not have tightened the knobs all the way and the front standard moved down a tiny amount mid-exposure? I'm used to shooting on a Linhof Technika and I never have to tighten any knobs there, so maybe I wasn't careful enough.

 

[_T_]

Sometimes the film can shift slightly in the holder after it’s inserted into the camera. It’s less of a problem for short exposures but for long exposures it can cause blur or something that looks kinda like a double exposure.

To avoid the it shifting it’s important to make sure the film is as far down in the holder as it can possibly go by firmly tapping the holder against the palm of your hand just before you insert it into the camera

 

[gbroadbridge]

Looks like the film buckled slightly outwards at the centre horizontally causing the top to effectively move down.

Is the image focused at the top/bottom but not in the middle? I can't tell from the image.

You could check if that happens with a scrap piece of film.

 

[koraks]

Looks like the film buckled slightly outwards at the centre horizontally causing the top to effectively move down.

I don't think so; in the center of the frame there's the same vertical shift. So it looks like the film simply shifted a bit/dropped during exposure.

an issue with lens rise

No, the margin of the image moved. If the lens had dropped, the rebate/edge area of the image would have remained the same, just the image elements would have created a double exposure.

The odd thing is how this would have happened in the first place, as the film holder would have sat horizontally in the camera during exposure and there's no room for movement along that axis. Unless the film actually did not sit inside the slots after all!

 

[MARTIE]

I agree, it looks like film movement during exposure.
Try putting the negative back inside the holders and check for film/holder play and tolerances.

 

[Rick A]

You've just experienced the reason why you should tap your film holders before inserting them into the camera.

 

[Vaughn]

You've just experienced the reason why you should tap your film holders before inserting them into the camera.

I agree. The problem with wood holders is that the sharp corners of the film can dig into the wood slightly and get stuck. This can happen while transporting the holder with film in it.

So a firm thump onto your palm before inserting the holder into the camera is a nice preventative.

If using the holder vertically, some older wood holders need to have the flap at the end held tightly when you thump it to keep the film from sliding down to where it’s not supposed to be

 

[ediz7531]

Thanks all!

Took a lil video. Yep that’s gotta be the culprit. I’ll give it a good tap next time. I’m curious, on 4x5 I’ve never encountered this issue. I guess 4x5 sizing is more standardized than 4x10?

 

[GregY]

Thanks all!

Took a lil video. Yep that’s gotta be the culprit. I’ll give it a good tap next time. I’m curious, on 4x5 I’ve never encountered this issue. I guess 4x5 sizing is more standardized than 4x10?

E, I tap every holder 4x10, 4x5, 5x7, 8x10..... it's now a habit & i don't even think about it.
Newer plastic holders like Lisco, or Fidelity are consistent in size.....but the same is not true of film sizes by various manufacturers. For film to slide into a holder there needs to be space....so that creates the potential issue.

 

[Vaughn]

I did not tap all my 4x5 holders during a recent Japan trip, perhaps on some long exposures. All were plastic film holders and a couple images did come out crooked on the film, but no movement or buckling during exposures.

My advice for holding the hinge area tight when 'thumping verticals" comes from having that issue with old wood 11x14 film holders. Probably not an issue with 4x5 plastic film holders. And I do not have these issues with 5x7. 8x10 and larger film holders is where I have had my issues.

One can shake the holder, perhaps in the long direction of the holder, to hear the film move freely, but it can be difficult to tell if both sides are moving freely.

Of course any thumping or shaking will send any dust downward towards the sky...so keep them clean!