Roll film holders - reflections at edge of frame

[dave_parry]

<p>Just wondering if anyone else gets this problem; I've got two 6x7 RFHs, one Horseman and one Wista. On images shot with either of these I get an internal reflection on the shots (all shots, but mainly noticable on area of even tone, skies etc) along the long edges of the frame. It seems to be coming from the inside edge of the 6x7 film gate in front of where the film/darkslide goes. It generally affects are area 1-3m deep on the film.</p>

<p>On my Horseman back I tried repainting the inside of the film gate frame matt back to cut down the reflections but I still get the problem (it seems matt black paint is actually quite reflective). At first I thought I just had a dodgy Horseman bakc, but it seems this might actually be normal. Has anyone else had this? Is this in fact normal for horseman/wista holders?</p>

[leicaglow]

<p>Dave, I'm having trouble picturing the problem. Do you by chance have a scan you can show us?</p>

[dave_parry]

<p>I'll see what scans I can dig out later on. Basically imagine a 6x7 transparency with a slight light reflection/band on the long edges of the frame, most apparent against the sky.</p>

[randall ellis]

<p>When you pull the exposed roll out of the back, does it feel loosely wrapped? Without seeing the actual problem it is difficult to say for sure, but it sounds like you could have a tension issue where the film is not being wound tightly on the take-up spool. This can allow light to intrude from the edges of the film, which in your case would be the long edge...</p>

<p>- Randy</p>

[dave_parry]

<p>Thanks for the idea, but everything is tight as it should be. If it was a light leak of that type I'd also have the light band across the rebate between frames, which I don't. I mean I'm 99.9% sure whats causing it, I really want to establish if this is normal, or/and if anything can be done about it. I may try sticking some thin felt/flocking along the offending edges.</p>

[vinny_walsh]

<p>Dave, I've had this issue with my shen hao 6x12 holder that had silver edges around the gate. I took a black sharpie to them and that took care of it. You could mask off the back and hit it with flat black spray paint as well. That should do it. </p>

[dave_parry]

<p>OK here's an example. I think this one was form my Horseman back.</p><div></div>

[bob_salomon]

<p>Rotate the lens on your lensboard and see if the problem moves. If it doesn't then the problem has to be the camera or the back. Since you have the same problem with two backs from two different companies the problem is in the camera.<br /> If you want the Wista back checked and if you are in the US, the Wista US service center number is 252 652-4401. They can check and replace seals on Wista backs.</p>

[dave_parry]

<p>Thanks for the input, althought I must stres that I do know already what the cause is, I just want to establish if this is usual for Horseman or Wista holders. Cheers.</p>

[bob_salomon]

<p>Not for Wista, that is why I gave you the contact for Wista service if you are in the USA. And having both backs do it makes it sound like your camera has a problem.</p>

[joe_harrigan]

<p>I’ve had this exact problem before. My problem came from light reflecting off the edge of the camera back <em>not</em> the roll holder. I use all vintages of wista and horseman roll holders and they do not cause this problem. Again I’ve used these backs on maybe 4-5 different cameras and the camera back has always been the culprit of this type of light reflection. In fact the horseman holders I have are beveled on the edge (toward the front of the camera when loaded) which would make light reflection off this edge go back into the camera not toward the film. Check the edge of the camera back opening. Cover it with flocking or velvet or some totally non reflective surface and your problem will be solved.</p>

 

[dave_parry]

<p>Thanks for the suggestion - however I can pretty much rule out the camera as the source since I've shot 4x5" with it with no such reflections. Althought granted flocking the back out might just be good practice anyway.</p>

[bob_salomon]

<p>Dave, you can't rule out the camera if you get the same result with two different backs of different manufacture. It can only be camera related or lens related. Something is creating flare in your camera. And it could be technique. Do you pull the dark slide completely out of your holders or do you leave it in and just pull it out far enough to not block the frame? The best practice is to take your back off. Pull the darkslide out till it fully exposes the film area and take a permanent marker and draw a line on the protruding darkslide so you know where to pull it out to. Now there can't be any light coming through the darkslide slot.</p>

[dave_parry]

<p>Trust me it isn't the camera, I know what a light leak looks like and this isn't it. There isn't any light coming through the darkslide slot, and if there was I can't conceive how that would lead to producing no fogging at the slot end of the frame, but instead cause thin consistent reflection-like marks confined to running all the way along both the long sides of the frame, on every shot, which are the same density all the way along, not being more severe at the darkslide-slot end (which is what you'd expect from a light leak). Anyway this is academic since I don't have any light leaks.</p>

 

<p>It also cannot be the lens, since that implies that the lens is projecting two long perfectly straight reflection-like patterns exactly 55mm apart into the centre of the ground glass that do not move or change shape or position when movements are applied, but do rotate 90 degrees when the back is reorientated, and are not visible on 4x5 film, and also all three of my lenses of different focal lengths and vintages must be exhibiting this behaviour. This just isn't possible unless the laws of physics have radically changed while my back was turned.</p>

 

<p>I would say however that I may have actually been mistaken regarding the roll of film I had developed which I thought was from my wista back. Having reinspecting it this weekend I suspect I'm actually just looking at entirely horseman-shot rolls and that the ones from my wista are the ones sitting on my desk waiting to go to the lab. I'll report back when the wista shots come back. I do note that with regard to the design of the film gate (which is the source of these reflections) the wista is of an almost identical design to the horseman, so will be interesting to see if there is a difference in the actual shots.</p>

[ilkka]

<p>I have had the same problem and to me the only possible cause was exactly what you described, reflection from the edge of the film holder. In my back it was painted black but still quite shiny. The edges of the film get the direct light from lens and additional light that reflects from the holder edge and thus cause a lighter line along the edge, but not quite to the very edge of the image (on positive). What I did was to take a metal saw and scrape lines along the edge and then paint it again matte black. Similar to what many cameras have as internal baffles. It has improved the situation. It does not occur with all images, only those where strong light is coming straight to the camera (sunsets and the like).</p>