Problem negatives

<p>I just shot a few test negs with my new (used) Wista VX field camera. I haven't shot 4x5 since college and until recently I've been away from film in general for a few years. There are a few problems with my tests. Pic #1 has a light band across the top of the neg, also there appears to be some staining around the edges of the film. Pic #2 has it as well but it's less obivous, but in #2 there is a light spot near the right side of the frame.</p>

<p>Both have vignetting in one or both bottom corners. I checked through the clipped GG corners and the vignetting doesn't appear to be coming from the lens. I assume it's from the back and/or the bellows mount, which has diagonal corners that would match this pattern. Is there any way around this? I used front rise but a moderate amount, well within the coverage of the lens. So if this is something inherent in the camera design then it will be a problem for me I'm afraid.</p>

<p>Both were somewhere around 1/30th at f/22 with modest front rise on Portra 400NC. I scanned them on my drum scanner, but the marks are all visible on the negs so it's not a scanning issue.</p>

<p>The light spot on frame #2 seems to be a light leak...to you experienced LF shooters does it seem like a holder or the bellows? Or is it impossible to tell?</p>

<p>The bands seem like maybe a processing issue, but I'm at a loss so again I'm hoping for some suggestions as to the cause...</p>

<p>Thanks in advance!</p><div></div>

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<p>Edges could be reflections from the edge of the film holders. Or it could be an processing problem. If you have a flash that can be controlled to a very short exposure, try flashing a sheet of film not in a holder, and having it processed.<br>

As for the clipped corners, you have to expect some "loss" around the edge of the frame.<br>

If the light spot on the second frame is the area at the right, it could be a failure of the tape on the film holder "hinge". Or it could be poor seating of the film holder on the camera.</p>

 

<p>I agree with John regarding the fact that it could be processing or reflections--not only off the holder, but also the frame that holds the holder--that might need some flat black paint applied to it. Correct me if I am wrong, but I think I actually see some issues with light on the top one at the opposite end of the film--top left. This all makes me wonder if there isn't a light leak somewhere that you need to ferret out. I had some similar issues with one camera and it wasn't traditional types of leaks, but a leak around the lensboard and bellows attachment on the front of the camera. Some gaffers tape fixed it all up.</p>

<p>The diagonal lines I see at the lower left corner appear to be very sharp and that generally means it is something close to the film. If it is real sharp, it is in contact with the film. You should put a sheet of film--or even paper--into a holder and then insert it into the camera. Pull out the dark slide and pull off the lens board and just look, you should see exactly what is causing it.</p>

<p>Checking the camera for light leak(s):<br>

Take the camera into a darkroom, extend the standards as far apart as the will go, remove the camera back. Use a 2 AA cell mini mag or similar flashlight set to spot focus at 2 inches, or a small fluorescent bulb (physical size) in a small table lamp and with the lights off insert the light source into the bellows. Look along the corners and around the lens board and lens. Any faint yellow glow to a white pin spot is a light leak.</p>

<p>Install the back with a film holder inserted on the camera and remove the lens board. Put the light source into the bellows thru the lens board opening. You may need to move the standards closer together to get the light source next to the back but the bellows should not be fully compressed. Look around the back and film holder seating for any hint of light. Remove the darkslide from the film holder and check the gate for any light leak.</p>

<p>You will have found a possible source for the problems or have eliminated the camera as a source for them when completed.</p>

<p>Nothing too revolutionary from me - the top light band is either dev (uneven due to some holder arrangement, or light-leak in the tank) or an artefact from the holder. But one extra consideration: is there any distortion in the power-cables coinciding with the lightness? If so, check how you've loaded the film in the holder.</p>

<p>Thanks for all of the help. </p>

<p>I can't find any light leaks in the camera after checking it as suggested. I think the light bands are a processing issue. On my higher-res scans I can see a noticeable discoloration (sort of a brown stain) around the edges of the film, which seems to be consistent with a processing issue. It doesn't show up too well in the web jpegs. </p>

<p>I put a sheet of white paper in a holder and peeked through the front of the camera--and sure enough the corner of the back bellows frame seems to be causing the corner vignetting. This is annoying as it's actually a lot of film area to be cropped out. Is this a common characteristic of 4x5 field cameras? I've never seen anything like it with the monorails we used in college or the Canham and Arca Swiss 8x10 cameras I've used more recently. </p>

<p>The only remaining mystery seems to be the bright area at the edge of #2. I'll triple-check the camera, but I guess if it's tight then it must be the holder or a leak that happened during processing.</p>

<p>Is there any way to check film holders for light-leaks without wasting a sheet of film? </p>

 

<p>I have only dealt with Press and Monorail cameras 4x5 and 8x10 and I have never seen a back or bellows frame protruding into the image area. Some long bellows on monorail cameras will sag into the image path with shorter focal length lens but that is easily compensated for by putting something under the bellows or using the tension increasing ring(s) made into the bellows. The bellows frame protruding into the image area suggest that there is an alignment or mounting problem with the bellows or camera back. It may have been assembled incorrectly.</p>

<p>Put the film holder into the camera and check in the darkroom as before but with the darkslide removed. Shine the light along the darkslide slot and the film loading door from the outside while looking at the inside. A piece of white paper installed like a piece of film may help show any weaknesses. Spread the standards for the focal length lens used at infinity for film holder checking. From the position of the bright spot it is either a reflection from inside the camera be it a bright spot on the lens board or lens mount ring or a slight leak in processing. Also look inside the camera with the back removed and shine the light around the lens/board from outside the camera. I have encountered several light leaks that would not show until the light source was at the correct position.</p>

<p>Looks like processing to me. Can you shoot another holder and send it to a different processor (or same processor on a good day)? Although, your holder pattern looks odd. What kind of holders are you using?</p>

<p>It looks to me like a processing problem, i.e. turbulence of the developer around an edge. Can you give us more details of your processing, e.g. tank, dish, holders, agitation etc.?</p>

<p>The holders are Fidelity Elite, the current style though I did buy them used. </p>

<p>What is strange about the pattern? I did crop into the rebate area slightly.</p>

<p>I don't know how the lab processes sheet film. They do rollfilm in a roller transport machine so I don't think they have a dip and dunk machine. Perhaps in tanks? I'll ask.</p>

<p>Hi.<br>

I agree with other contributors, but I could add something slightly different.<br>

In #2 image, the light could also come from the pressure or your fingers holding the holder - the chassis :) .<br>

The light comes from the bottom of the holder. Maybe the volet was not totally re-inserted in its position, or maybe being old the volet could result a little "soft". The pressure could open a microscopic and temporary leak that could mark the negative. Note that if the leak was in the bellow or if it was a real leak, the image should be much more affected: a total "velure" in case of the bellow, or a totally white area in case of holder's leak.<br>

For the horizontal lights, other than the poor insertion of the volet, the holder frame could be a little too glossy, and since the area is an almost white sky, some reflection could appear.<br>

Good luck, Massimo</p>

<p>Just a comment on checking for light leaks. You have to be in a dark room and you have to sit there for about 5-10 minutes before turning on the light in the bellows--or have a very cool bulb in there. Your eyes will not see the minuscule leaks until they have completely dilated. I tried several lights to no avail until I got a regular light bulb, 60 watt, and put it in a socket I took off one of those cheap clip on lights you get at a hardware store. I put put the cord through the lensboard opening and then tape that up using good masking material to prevent light coming out. After I have been in the absolute darkness for 5 minutes or so, I turn on the light (I use a power strip with a switch to do this). You will be amazed what you see after 5 minutes or so versus what you didn't see right away. You also need to be able to move around the camera and look at all angles, sometimes the leaks are very directional.</p>

<p>@John A: correct, it could be... but I think those whites in the images are too much for such small leaks: these should be about f/1200 even if they were close to the film, and in the for or five seconds in wich the volet is off for the shooting, I doubt they could give those white areas.<br>

But of course it cold always be like you are saying.</p>

<p>The lab said the bands on the edges are from their film holders. I guess they're processing in tanks. They said it was normal and that I shouldn't expect to be able to use the whole frame. Guess I need to find a new lab!</p>

<p>Given that attitude I'm wondering if the light leak on the side of #2 was their fault too. But I'll repeat the test with the same holder as well as a different holder and a different lab to check. I was careful to make sure the darkslide was inserted properly and sufficiently, and looking at the design of the holder I don't see how a leak could occur in that position. But another round of testing is in order.</p>

<p>Thanks for all of the suggestions!</p>

<p>The original test procedure for checking for light leaks in a bellows was to use a 40 watt clear appliance bulb in a small lamp or clamp on light socket. The problem with this is the bulb gets very hot fast and you can burn the bellows with a slight touch of the bulb to the inside of the bellows. Newer compact fluorescent light bulbs in the 13 to 15 watt range should work very well. They also get hot but not as hot or as fast as the 40 watt appliance bulb. <br>

The advantage to using a Mini Mag is its compact size allowing you to get into tight areas, the disadvantage is you have to sweep the entire bellows area with it. Be sure to use fresh batteries for light leak testing.</p>

<p>When removing the film holder from the camera relieve the spring tension of the focus panel on the holder then remove the holder. Pulling back on the holder with the focus panel spring tension on the holder will eventually crack the edges of the holder or cause the top to side joint to separate causing a light leak.</p>

<p>The lab is full of.....well......... I routinely shoot 4x5 and get full usage of my negs and chromes--and have for over 30 years. That doesn't mean that I haven't seen some issues from time to time, like those above. The difference to me is that they seem to be all the way around the film, I generally see this sort of thing, when it does happen, in one place and have chalked it up to an internal reflection--off the camera or holder due to the angle/brightness of the light.</p>

<p>With the light leak I mentioned above, I started to notice it more often, but in most cases, it was where I knew I had removed the dark slide and then waited for a fair amount of time before clicking the shutter--waiting for the subject or for the wind to die down or one of those sorts of things. I also noticed it didn't happen on all the film I shot for a particular scene--sometimes I could get one off faster than another, depending on the wind or other conditions. This made it seem more like it was a light leak.</p>

<p>As I wrote this, I do remember that when I got a new wood field camera--a new version of one I had had for years, that I got similar problems because the film holder actually seated in the back differently. You had to push it in and them pull it back a tad--the latter step not necessary with the earlier model. If you didn't, it formed a bit of a gap that caused similar issues as this, except again, only on one side. Test the light leaks with the holder in place and check around it to be sure it is seating properly.</p>

<p>Thanks for all of the tips. I shot another test, this time with the same holder but a different lab. Sure enough, everything was fine. And just for fun, I pulled the darkslide and let the exposed film sit in the camera for a while (as if I were waiting for wind to die down, etc). There were no leaks this time and no uneven development. The new lab uses dip and dunk, which I've always preferred in general. The old lab was using rotary tanks. So it wasn't my fault after all ;).</p>

<p>One more question if anyone is still listening...is it normal for the marks left by the processing clips to be so far into the image area? I'd have to crop quite a bit off of the left side of this photograph (or spend time retouching them out). When I used to shoot 8x10 I don't remember this being a problem, though I guess the margins are a bit larger on the bigger format. </p><div></div>

<p>Noah-- I have a feeling that everyone's diagnoses for the problem are incorrect. Upon looking at the images it was clear to me that the problem of increased exposure is due to flare--bellows,lens, and film back frame. The fact that the image in the second test didn't have the increase in exposure could be due to the difference in the subjects. Both images were made using a wide angle lens <strong>BUT</strong> the first subject was mad using the rising front, increasing the chance of flare from the bellows. I also suspect that both subjects were photographed without a lens shade. Many years ago I had a 4x5 Korona field camera. It was nice and light, but the bellows were too small tat any time a light source was anywhere near the field of view, I got the same thing in all of my images. After that I switched to a 4X5 Deardorff Special ( really a 5X7 camera with a 4x5 back). That was the end of the problem. I'll be interested to see your results.</p>

<p>Bill Hayes</p>