Nice RB67, but there's this one little thing

[yessammassey]

One more test frame. For light leaks. I'm going to do it.

But in the meantime, to anyone who says they see no visible issues; is there really nothing in the first set of pictures, of the wall, that indicates something amiss with the exposure? Nothing in the final picture, of the house, in the shift from red to yellow in the brick work, that is out of the ordinary?

I ask because, let's say that I do decide to switch to a different camera. Would I be right to offer this RB67 as 'tested and fully functioning' with no issues? On eBay right now a good RB67 kit with two lenses goes for $400, at least. Would that be a fair price for this kit? I think this 65KL in near perfect cosmetic condition would probably fetch a little more if sold separately, but generally speaking that's a good price? Given the photos I've posted, this is a perfectly functional camera with no issues?

 

[paul ron]

you can do this test with a lens but lens cap it or seal it really well.

check the body cap doesn't leak?

 

[MattKing]

Your camera and lenses are working perfectly. What you are observing is the natural result of your scene, the light illuminating it, and the laws of physics. Those most recent examples are normal and natural and are consistent with how we see the world.

Your RB67 has a "sensor" that is approximately 56mm x 65mm. Your lenses have to cover that format, and they have to be able to image three dimensional subjects over a wide range of distances. They do that superbly. They show gradation of colour and tone and through that communicate a natural depth and complexity to your photographs.

Your micro 4/3 camera has a sensor that is 18mm × 13.5mm. The output of that sensor is likely to be digitally adjusted (even in RAW) to even out colour and exposure over the frame - thus the unnatural look of your digital example. The lenses only need to cover that relatively tiny sensor, and their "peculiarities" can be measured and adjusted for, either in the camera or later in "post".

Your light source is multi-coloured and multi-directional. Your subject is multi-textured, multi-coloured and reflects light in multiple directions at once. The subject will appear different (both as to colour and as to illumination) depending on the angle of view. The angle of view is different for different parts of your scene. All of those realities result in the real world actually appearing the way your examples show it to be.

If you had a two-dimensional smooth subject, you photographed it with lighting that was much more even, and was controlled in direction and colour and you used a process lens at a distance which it was optimized for, it would be natural to see even colour and illumination.

It is rare for me to say something like this, but it may be that you would be happier with the (somewhat unnatural) output from digital.

But if you want the benefits of those beautiful, large hunks of film you can get them with more even colour and tone, as long as you take control of the light and consider some of the options that light modifying filters can give you.

 

[Sirius Glass]

You do not have a light leak. The dark corners in one of the photographs of the bricks is from the 1/cos4theta lost, which is in all lenses to a greater or lesser extent based on angle of the view [theta].

 

[MattKing]

You do not have a light leak. The dark corners in one of the photographs of the bricks is from the 1/cos4theta lost, which is in all lenses to a greater or lesser extent based on angle of the view [theta].

Sirius is correct, although the visibility of the effect is increased by the contrast choices you have made in the digital parts of your process.

Your pure digital example probably just compensates the effect out using firmware/software.

 

[horacekenneth]

nice photos!

 

[yessammassey]

Sometime soon I will check for any kind of light leaks by making a dark exposure, even though it hopefully won't turn anything up.

I guess I need to check out some more medium format photography from other photographers. I've always really liked the look of medium format film, and I've never been as critical an observer of other peoples' output, in a technical sense, as I have been to my own out of this camera.

I started off with medium format trying to slum it with a Keiv-60, and even though the CZJ lenses I've used are great, the mechanical cloth shutters on every camera copy I've owned has shown dramatically uneven exposure due to capping at one speed or another. The whole reason I bought this RB67 system was to get the leaf shutter lenses that wouldn't cause linear luminance gradients running across the frame. So I'm looking very closely at exposure and color consistency discrepancy between the edges and the center. But the sense I'm getting from most of the response here are that all of the hue shifting I've brought up is normal and to be expected.

Your eyes need calibration.
Your image, eyedropper center of the marked area starting on the far left R-76, G-106,B-132; R-122, G-151, B-185; left center just above the top of the marked area which is more in line with the other two areas R-102, G-133, B-164; R-89, G-118, B-150. Converting to grayscale block 1-46%, block 2-46%, block 2a-46%, block 3-49%. PS7 used as that is what I have on this computer. Right side not checked.

Were you using point sample? The blocks of color were taken from 5x5 average samples taken with he eyedropper tool in PSCC.

There's going to be some variation no matter what, depending on where exactly the dropper is placed, but here are the values I got:

• Left column RGB values: Top- 104,132,169; Mid- 162,178,201; Bottom- 150, 168, 190. Grayscale (T,M,B) 50%, 69%, 65%
• Right column RGB values: Top- 117, 141, 167; Mid- 174, 186, 200; Bottom- 174, 186, 200. Grayscale (T,M,B) 54%, 73%, 73%

The main thing I was trying to show here was the difference between the three eyedropper samples from the left side of the frame, and the three from the right. The two outermost point samples on the extreme right and left of the image are outliers from rest because they're subject to more darkening, but if you compare the two blocks in each row (eg middle left to middle right), the left side blocks are show consistently less Red. There is a hue shift across the frame.

I don't question the statement that our eyes 'fill in' and 'smooth out' what we see. And I agree that how our eyes see and how our brains process visual information is going to affect how we see color in the world compared to how film registers it. But, if we just stay on that last picture of the house... There was nothing in the scene that would have caused the eave to reflect more red light on the right, and nothing to cause the brick to be more reddish-blue on the left, and nothing to make the leaves on the shrubs look more yellow/green on the right. There is nothing but an old fence behind the camera in that shot. Farther out there are some trees and another house.

The camera was pointed directly at the sun, and yet in the image you would think that the sun was to the right, as the left 1/3rd of the sky is cooler.

I'm on the verge of just accepting it and going about using this camera for its normal purposes, which include occasional paid jobs. I still think there's something going on, but whatever it is, it doesn't appear consistently, and isn't really identifiable. It's just that it isn't going to be correctable in traditional prints, as far as I can tell. And while its possible to correct digitally, it's a much more involved and imprecise process, requiring a very low opacity color mask.

 

[shutterfinger]

Were you using point sample? The blocks of color were taken from 5x5 average samples taken with he eyedropper tool in PSCC.

Yes I was.

The only thing I can think of that might affect color hues is the lens coatings. If there is a problem with them then it should be visible to the eye when inspecting the lens.

Years ago I bought a used Sinar F1 from a authorized retailer in the area. I loaded a film holder with ISO 400 B&W film, inserted it into the camera with the bellows fully extended, pulled the darkslide, took it outside into full sun and turned it every possible angle for over 5 minutes. When I developed the film it was even fb+f. I loaded some more film and went out and made a few exposures. When I developed them they all had secondary pin hole exposures on top of the main image.
I sat the camera up on a tripod, extended it to full extension then in total darkness I put a 40 watt light bulb inside and saw a pin hole at every fold of the bellows, 3 per pleat at all 4 sides.
Unless its a gaping hole full sun will not expose a leak let alone where it is. A bright light inside the camera will show every weak spot. The weakest will be a faint yellowish spot and full holes will be white. I currently use CFL bulbs in place of incandescent bulb and LED bulbs should work equally well.

 

[paul ron]

but he suspects a leak is causing the color problems while shooting under normal conditions. so taking a blank frame will prove a light leak at the exact positions he points out in his photos.

we'll have to wait and see how his blank shot comes out.

 

[yessammassey]

It will be forthcoming. Just waiting on the 400ISO B&W film to show up in my mailbox.

 

[yessammassey]

So I did the light leak check. Results were... somewhat inconclusive. Used a very bright LED (my phone's flash light) and circled all around the sealed up RB67 as it was making a Time exposure. I repeated this a few of times with the bellows & WLF open/closed back rotated or not rotated during exposure, for a total of four exposures. (I am thinking now that maybe it wasn't a good idea to rotate the back while making an exposure... didn't seem to resist or cause any damage that I could tell, at least)

I opened the scans in photoshop and cranked up the curves to show a brighter and more contrasty image, bringing out more subtle variation. A pretty hasty scan job... lots of dust, but it doesn't really matter much in this case.

Scan of the first ~40% of the roll. Kind of hard to tell where the frames begin and end.

Start of roll is on the right side of the first scan. The first exposure is also when I was most keen about really bathing the camera in light from all angles for several minutes. It should be that lighter area to the right.



Note that there are a lot of vertical bands.

Those same vertical bands don't seem to appear as strong in this scan from near the end of the roll. I left about 60% of the roll "unexposed". It would only have been exposed to any possible light leak very briefly as I was continuously advancing the film after the 4th exposure.


So, I'm left with the sense that maybe there is a very, very weak light leak that shows up as a vertical band. At first I was thinking that it was just a development process thing, but the 'exposed' part of the roll seems to have way more vertical bands. The last 60% is more uniform.

I guess maybe I need to go in and do a super-dilligent seal foam replacement. I'm thinking that my initial resealing job didn't quite make the cut.

 

[paul ron]

oh great the results are in.

those bands may be from the light source in your scanner.

look directly at the negatives surfaces? also, perhaps on your tablet or the enlarger baseboard? do you still see those bands? im sure it would be difficult to tell on clear negatives.

rotating the back during an exposure should not leak light.

the dust in scans are usually digital noise.

ive never seen light leaks in the types of bands you exhibit here. if it were a leak, youd see definate localized streaks, spots or flares, but always very consistant n reproduceable.

i wish you did this test outdoors in the sun rather than using an led phone light.


just one more thing.... are these bands consistant with the problem areas in your initial examples at the start of this thread?

 

[shutterfinger]

Go to your local hardware store and get a clamp on light http://www.homedepot.com/p/75-Watt-Incandescent-Clamp-Light-HD-200PDQ/205139241 and a 40W clear light bulb http://www.homedepot.com/p/GE-40-Wa...r-Light-Bulb-2-Pack-FAM24-40A15C-2L/100493756
The reflector should be easy to remove or you may find a clamp on light without the reflector. Clear light bulbs work best but CFL and LED bulbs can be used.
In total darkness put a bright light inside the camera. First with the lens off and mirror up, WLF open, darkslide removed with no film in the roll holder. A light leak will be anywhere from a dim yellow dot to a bright white spot.
Next attach a lens and remove the roll film holder/back. Repeat with the light inside the body to test the lens mount and leaf shutter.
If any leak exists you will know precisely where it is and how strong it is.

You'll also be amazed how much light the black inside of the camera soaks up the light. Light bulbs get hot, be careful not to touch the bellows as it will burn a hole in them.

 

[yessammassey]

So far I've found no light leaks from application of bright lights into the camera, from the front or the back, or closing up an LED inside. Sometimes it feels like maybe the film back has a little bit of play even when it is locked on. Maybe this could be a point of light intrusion when I'm holding/moving the camera and happen to pull on the back a little bit..

Paul Ron, I have checked it on my DSLR scanning rig. The vertical bands are not as obvious as they are in the scan... but they're there - in the same places. Triple-checked by putting back in the scanner but flipping the orientation of the film so those parts in question are being scanned on a different part of the glass. Results were identical.

I tried lining up the first two frames from this roll with the last roll of film that I shot. Just traced over frame edges in sharpie. Here's the result, from the second flatbed scan:

Even if we adjusted their positions, there's not really any way to space out two frames so that the bands appear at the same general place on both 1 and 2.

-But-

If we consider that maybe the beginning of the first frame was a little farther up the roll (which it could have been), and that the first frame was subjected to a longer 'bath' of light on the camera (which it was), then maybe it is possible to see that there was a little bit of light leaking in on both sides of the frame.. if we place the frame like so


But this isn't repeated in the second frame. If there is light coming into the camera and causing this effect, it is a minute amount.

I wish I had done this in bright daylight, too. But I was impatient and did it in the evening after work. It's too bad, because I'm seeing now how much easier it would have been to compare frame to frame if there was always a constant amount of light all over the camera instead of in different places over time.

The only things I can think to do now, besides take it outside and blow another roll of film on another test tomorrow afternoon, are:

... to get a brighter, safe light and really blast it inside the camera. Maybe I will find a leak this time.
... double check every light seal and redo anything that looks questionable. This may include the dark slide seal, which I have never tried to get at or replace.

To those of you with enough experience to know, does this vertical banding/streaking indicate a possible process issue? Could it be that my fixer is starting to wear out? Is it possible to have varying density in the emulsion due to improper agitation or bad chems? Or does there have to be a latent image of some sort to cause the kind of blotchy bands or streaks that I'm seeing?

 

[paul ron]

and shoot every other frame dark, and between do a regular shot or sky to separate the frames.

to get to the darkslide seal, remove all the screws on the plastic face... the film mask. the seal is a stainless spring steel with flocking on it. just clean the dust, open it a bit so it applies a bit more preasure.

suspect the hinge or the latch seals?

 

[shutterfinger]

And if there are any bright spots on the inside of the camera paint them with black paint, flat or satin. Golden heavy body acrylic artist paint #1040 carbon black works well. I dilute it 1:1 with water and apply 2 or 3 coats, works on cloth shutters and inside bellows as well as camera metal interiors.
Weak fixer/insufficient fixing usually leaves film milky. You can refix film up to a week after the initial fix and correct improper fixing on B&W film, it may work on color film which should be run through the stabilizer after refixing.

A tubular bulb may be more suited to your camera for testing, I used one once but don't remember the camera I used it on.
http://www.homedepot.com/p/40-Watt-Incandescent-T10-Clear-Tubular-Light-Bulb-415869/202796445

 

[Theo Sulphate]

Make some nice landscape photos and large prints. Show them to people. See if they like the photos; ask yourself if you like the photos.

 

[yessammassey]

I'm bringing this thread back from the dead for an update. I had decided that however my photos were turning out was good enough, and began using the RB again. Then before long a nice, very very obvious and intense light leak began appearing on every frame I shot. I did the LED-in-the-dark test again, and sure enough there's a light leak at the top of the dark slide slot.

Opened up the slide holder to get a handle on what needed to be resealed, but instead I lost my grip and the little felt-covered light baffle insert got flipped around before I could see how it sat originally.

Anyone with experience working on these things able to help me out? Does it go like this:



or like this:

or like this...?

 

[paul ron]

your last picture is correct. remove the dust from the flocking using a post it sticky end. bend the springs ever so slightly to incrrase the tension a bit n help keep it uniformly against the mask to complete the seal.

 

[Kevin Harding]

Replace it carefully. The flocking here is vital to ensuring you don't get light leaks from inserting or removing the darkslide in any kind of lighting. The darkslide being bare metal reflects tremendously well into the film back causing delightful light leak splotches about 10-15% of the way into the image area.

I don't think that you have light leaks in your camera, aside from any that may be introduced with the disassembly of the back. Where the colours subtly shift in your images are where I'd expect them to shift, as the angle to the film shifts and their physical orientation changes slightly.

I like your style, if you've been going for an urban minimalist documentary approach. Appeals to me in some strange way.

 

[yessammassey]

Thanks. And thank you for the help, Paul Ron.

I've been working on building up a bigger portfolio of this stuff, but my last roll came back with a glowing apparition present on the same part of each shot.

(It's a style of photography that I feel really benefits from the kind of subdued color palette and high detail of medium format color negative films like Portra and FujiPro. I wish that CineStill and Fuji Natura were available in 120 size, too... as an aside, I've been searching for a very sharp 35mm lens/camera to broaden my available film stocks, but can't break the bank with a Leica right now.)

Here are some examples. The first one is from the last roll (with the light leak) but I photoshopped it out of the scan. You can see traces of it in the pavement to the right, near the bottom.



[URL='https://flic.kr/p/M4n4vN']





This last one is from a 6x9 camera

Yeah this leak is new. Although I think there could have been extremely minimal traces of light leakage from the same spot before, as the new bright blotch's location on the frame is roughly congruous with the location of the very slight color shifts I was seeing before. That is, about a finger's width inside from the right edge. Which, when I think about it, I wonder... if the leak is on the right side of the camera, shouldn't the effect be seen on the left side of the image? This is a basic concept that I've forgotten since my HS photography class. Maybe it's reflecting off something internally.

Anyway, after fluffing up the springy felt piece, no more light is coming out of the dark slide slot when I do the LED test. However, the light from the slot was obscuring another leak, this time from just in front of the slot, where the revolving back connects to the mirror box. I have to apply a tiny amount of pressure to really see it, even in total darkness otherwise, but it's definitely there. But the light seals around the back are new, and bear the imprint of the mating surfaces all the way around, so besides doubling up on the thickness of the seals, the only way I could see how to fix this would be to tighten the fasteners between the two pieces... I wonder if that's possible without doing major disassembly. There are four bolt heads on the revolving back that slip into catches on the mirror box. The bolt heads appear to have flathead screwdriver slots in them, which would suggest to me that they can be adjusted, but they seem to be locked up tight.

I'm hoping that I can just find a new revolving back. I'm going to mess with this one and see if I can tighten it up in the meantime.[/url]

 

[paul ron]

leave those lugs alone. your seals arent thick enough if its still leaking or you didnt apply them properly, usually the curves are the problematic spots in application.

 

[yessammassey]

After spending some more time in the darkroom with the LED inside the closed up camera, it really looks like the light is coming thought the pivot point of the revolving back... so light is getting in through the sliding metal track that the back pivots on.

This part is supposed to be assembled light-tight by design, but I can only think that it got wrenched out somehow. There must be some bent metal somewhere. No idea how this could have happened, but I think the only solution is to buy another one of these parts.

There's a Pro SD back available right now. Probably going to pick it up. They're compatible with the Pro S, right?

 

[MattKing]

There's a Pro SD back available right now. Probably going to pick it up. They're compatible with the Pro S, right?

Yes.
Are you sure that the problem is with the back, and not the rotating adapter?
Those rotating adapters do require maintenance, are moderately complex, and are exposed to heavy use.
In fact, you can say that about all medium format single lens reflex cameras - Mamiya, Bronica, Hasselblad, whatever. They were designed for a market where it was assumed that owners would have their cameras professionally maintained on a regular basis.
The same thing applies to the medium format TLRs, even if their relative simplicity means that the amount of maintenance necessary for them is likely less.
My advice: get your camera properly set up by someone who services them professionally.

 

[paul ron]

After spending some more time in the darkroom with the LED inside the closed up camera, it really looks like the light is coming thought the pivot point of the revolving back... so light is getting in through the sliding metal track that the back pivots on.

This part is supposed to be assembled light-tight by design, but I can only think that it got wrenched out somehow. There must be some bent metal somewhere. No idea how this could have happened, but I think the only solution is to buy another one of these parts.

There's a Pro SD back available right now. Probably going to pick it up. They're compatible with the Pro S, right?

that the first time ive ever heard about that in 45 years working on cameras.

if you replace it, can i have the old one for an autopsy?