weird band of underexposure with new canon ftb

[weasel_bar]

shot some fuji reala with newly refurbished canon ftb. weird band of underexposure on several negatives, on the right. Have not seen this before. is it related to the quick loading device? It is visible on many frames on two separate rolls. see attached.

[weasel_bar]

looking at the FTB documentation, and it has a horizontally traveling shutter., which might lead to a vertical band if it's in the way during exposure. So could it be the shutter timing is off?

[jim_bielecki1]

What shutter speeds? Your shutter could be capping, which is when curtain overtakes the other as they travel across the film plan.  Mostly happens at very fast speeds, like 1/500th and faster.

[weasel_bar]

Some of them could have been 1/500 or 1/1000. The bands have different widths on different frames, but always go to edge. So probably varying by shutter speed. What's the solution? 

[chuck909]

Capping!  It will have to be repaired.  Either that, or frame your shots with that in mind and crop.  I have had the problem with my F1, and have often seen it on Ftbs.  In the past I sent my F1 to Ken Oikawa, but he is now retired.  Seems as though a lot of folks here are recommending a place i North Dakota now.   

 

This from another thread:  Steve Sweringen is the repair tech that Ken Oikawa is recommending.  His contact info:  Steve Sweringen, Camera Clinic, 100 2nd Avenue NW Mandan, ND 58554, 775-829-2244 .

Edited April 17, 2023 by chuck909

[John Seaman]

OP, please refer to my response to your identical thread posted in the Wet Darkroom forum. It's best not to put the same question in different forums.

[weasel_bar]

Ok sorry for the double post. And thanks to all for the information. 

[Gus Lazzari]

"newly refurbished canon ftb - What's the solution?"

This is a classic 'Brake' issue. When one sees a defined line such as yours, it's the 1st curtain hitting a DRY or overly tightened brake (the 2nd curtain pushes its way against the prematurely halted 1st curtain).

This is a REDO for the servicing tech. He needs to first lubricate, then if the issue isn't remedied, then the brake has to be adjusted; this of course assumes that the shutter specs for tension & lubrication are met...

[weasel_bar]

@Gus Lazzari thanks. I talked to the technician, who said it's "shutter bounce." I think you are referring to the same problem. Sent back for repair. Fingers crossed.

[Gus Lazzari]

"said it's "shutter bounce." 

Okay, he either doesn't wish to explain it to you, OR he doesn't know that shutter bounce causes A BRIGHT LINE of re-exposure.

 

"you are referring to the same problem"

Not really. - It's definitely *Brake related, BUT, it's the opposite of "bounce"...

 

* "the 1st curtain [is] hitting a DRY or overly tightened brake"

[gwhitegeog]

Yes, it's shutter lag - the blinds are not synchronized.