Blue cast to transparencies

[Mike Mahoney]

I'm getting a fairly pronounced blue cast on the majority of shots taken with a Schneider 90 F8 SA. I thought it may be the film, Fuji RDP 111, but the color ca st also appears with Agfa RSX 2. I've tried various amounts of over/under exposu re but the cast persists. I can take it out in PS, but would rather have a good original - anyone offer suggestions? This color appears in both shade and sun sh ots, so it's not the blue cast associated with open shade shots. I'm going to tr y an 81b filter tomorrow to see if that helps, but I'm wondering if anyone else has had the same experience?

[Steve Singleton]

It would seem that processing flaws would be a more likely cause than your lens. Are you using a trusted lab and have you consulted the lab manager?

[Mike Mahoney]

Thanks, Steve, I have had the same problem at two different processors.

[Jacque Staskon]

So... is it a blue..blue or a cyan blue? It could still be processing, even though you have tried two labs with the same results. Have you evaluated your transparencies with a color checker? Or are you looking at them with a less than optimal light table and lupe? Have you made prints from these transparencies, if so what were the prints like?

[Mike Mahoney]

Jacque - it's more of a cyan blue, and I don't have a color checker exactly, but I can get color info from Photoshop. I've been using the same daylight balanced Logan PortaView box for years, and the problem is not there - other transparencies on this same box are fine. I haven't made any prints, and printing is not really a concern, as most of my final output is a digital file. I've tried a warming filter today, and that will help, as the blue trannies look much better on the table when seen thru the 81b, but still the cast should not be there. Incorrect processing is probably the culprit, but I've tried two different processors with the same results, and we have no other 4X5 E6 processors close to me at all - in fact the second processor is in another province, and has a national reputation for high quality work. The mystery continues ......

[Steve Singleton]

On one occasion, I loaded one sheet of film backward in the holder, so the anti-halation backing produced a color cast on the developed film (actually the mis-loaded film was more pleasing under the dusk conditions I was shooting in). If loading is clearly not a factor, are you using more than one lens and getting only faulty results with the 90? If so, I'd agree it must be the lens. If not, I would see if someone else could expose the other side of the same holder with another camera. That should quickly establish whether it is the film or lens.

[Jim Galli]

A couple of ideas.

Talk to the processor folks. Blue cast is often caused by too low a PH in the first developer/ or the color developer. Ask them if they've made any recent changes that would lead to this ie. switched to different companies chems or whatever. Ask them if their ph meter is calibrated.

Second, is the stuff that's going blue shot at the same altitude as the "normal". Up around 5500 ft and you would need a 81A to compensate for the increase in ultraviolet in that atmosphere. Somewhere around 8500 ft and you would need an 81B to get you back to 5500 degrees color temperature.

[john g]

Sounds like your labs are running the film through faster and rasing the temp. to compensate to save time and not replenishing their chemicals on time to cut costs. I have even been to Kodak Q labs {the best of the best suposedly} that do this. Just keep testing labs to find the best one. Here is a sugestion expose 5-10 sheets of film at the same exposure of the same seen and send one each to 5-10 labs. You will be suprised at the difference.

[kthompson]

There about a dozen things or more that could cause chrome films to run blue in E6...the pH of the color developer is one, but in my experience (not dip & dunk, but a Wing Lynch) Ektachrome will go blue if the color developer is acidic, and Fujichrome will drift to a magenta/red cast. If it's too alkaline, the opposite happens...Fujichrome goes a sorta green/cyan and Ektachrome runs yellow. On the lab side, you can still be within +/- 10 pts. and be "in control" in the real world....if it is the processing, your best bet would be to use cc filters to tune your film to their process, or to just find another lab that's a better match. Because, even a Q lab could be a bad fit...

[Aaron Francis]

All the suggestions are valid however, the problem could be simpler, ive never used a Schneider camera before, however could it be possible that it is a very subtle light leak in the back? Could there be reflections inside your lens barrell? It might be an idea to take the camera to a technician and run these possibilities by him. Good Luck

[kthompson]

Well, could be your viewing conditions, light table CRI etc....I guess the question is just how blue is it? Can you use CC filters and accurately tell how off the color balance you are? How do the chromes look if you view them on the lightbox at the lab who's running the film?

[Mike Mahoney]

I haven't measured how too blue the trannies are, but the filter that brings them back to a normal level is a cokin 027 - which is approx. 189R, 166G,and 117B. I don't need this info, I've looked at thousands of trannies on this box, and with window light, and these are certainly more blue than any others. Just this morning 36 exp of Velvia in 35mm taken in the exact same conditions - most were duplicates of the 4X5 shots - came back from the same processor, and the color is fine. I'm expecting several shots taken yesterday with the 027 to be back early next week, so there may be more clues then. As to the magnitude of the problem, it's been perhaps 50 sheets with three seperate processings at two different processors - one is a local tank processor in his basement, the other a national Canadian shop. My regular local lab cannot handle 4X5 E6.

[kthompson]

Uhmm....look, why don't you shoot the same scene on your 4x5 with 2 different lenses, and then compare those results. You can't compare 35mm Velvia to 4x5 Provia 100F, or Agfachrome for that matter. It's all different film, all films behave differently in E6. What does the RGB value of a cokin filter have to do with even coming close to a CC filter? And for that matter, why even bother with color correction if a monitor is the end product? Buy a set of CC filters, 05 units, or 025 if you're really picky, and use those to correct & judge the CTs. If it's off by 10 pts., don't even bother using them, start looking for another lab, or buy another box of fresh film. +/- 10 pts. is normal, as is +/- half stop. When you say 50 sheets, are you talking about 50 sheets out of the same box & emulsion number? Are you shooting gray market film? I thought you were asking about a cast across 2 different films, both shot on the same lens. I just checked a wratten 81A against a cc10Y, an 81B seems like it would be rather "peachy" in color...maybe you have a cyan/blue cast?

[Mike Mahoney]

Thanks for your additional suggestions - I've only one lens - trying another lens is the next step, but I'm unaware of any other LF shooters near me to borrow one. I had used two different brands of fresh film, and two different processors - I really don't want to get into the whole color correction thing as it should not be necessary. I've been taking the cast out in PS but it can be time consuming depending on the particular transparency. I guess my whole point is that my trannies have a blue cast, it persists with different films and processors, and the cast is not present with another camera with similiar film under the exact same conditions - that would suggest the lens, but I know that's unlikely. Adding to my frustration is the fact I've never been busier, and the majority of my architectural work requires color accuracy - so I'm spending time trying to obtain something that should be there in the first place. could be worse I suppose ........

[kthompson]

I'm not saying that there isn't a possibility of it not being the lens's fault....all I'm trying to say is that using CC filters is a way of life with chrome films. If you're not running your own E6 and tweaking it to match your film, the chances of you getting a dead on match are slim...you either have to use CC filters, or live with the results your lab is giving you. Plus, films have their own characteristics, and there are certain colors that will not reproduce accurately at all with any film. Without knowing exactly what color it is, or how much the cast is, nobody can tell you what is going on. CC filters are the standard, not warming filters. The next best thing for viewing are those Kodak color print viewing filters, and a decent light table. It could be that you have multiple probelms. The lens has a certain cast to it, and maybe the process is a little funky too. The only way to tell is to start nailing down each possibility individually. When you judge color, look at the midtones of the scene, don't judge the highlights or shadows. If you want to run a test, shoot a gray card or a colorbar in the shot. You need a standard to check against. I have to do this at work, and sometimes I have a hard time telling what is cyan or blue, or red or magenta....it can be tough.

[Struan Gray]

When I test labs I re-wash the film when I get it back and see what colour the wash water comes out. If it's not clear it's usually blue or cyan, and with the benefit of hindsight I think I can see a clearing of a cyan cast in the highlights. Try washing a test sheet in plain water and see if things improve. It'll still be the lab's fault, but you'll know why.

For further tests, if you can't find another lens, you could try a pinhole exposure. You wouldn't need an 'optimal' pinhole, just something that gets an image on film.

[Mike Mahoney]

Thanks Struan, I put a slide in a tray of plain tap water this morning, and let it sit for two hours - no agitation - and the water has turned a purplish color - I know nothing about washing, would this indicate a processing fault?

[Struan Gray]

There are others in this thread who know more about E6 processing than I do, so I'll leave informed speculation to them. I've been told that the colour is anti-halation dye, and I've been told it's residual colour couplers. Either way, if it's on your film and shouldn't be, you'll get a tint.

Two hours is a long time to wash, but at least you got a result. Jobo recommend multiple 30s washes for a total of 5-6 minutes. When I've done E6 myself the water has come out clear at the end of that sequence. Note though, that multiple washes are much more effective than a single wash with the same volume of water.

I don't use the labs whose returned film gives a coloured wash. I don't know whether they're skimping on the wash part of their process, or whether it's something earlier in the process (incomplete blix?), but it seems to me that if a simple water bath can shift the colours of the image there's something they're not doing right. Perhaps the more experienced E6 processors can comment?

[kthompson]

That's what is known as leuco-cyan dye. We do the same thing, but for us it's to control the magenta color shift of the Fujichrome film we run. We go for extended final washes. The final rinse will sometimes turn a magenta color not unlike the look of hypo clear after T Max films. There's a fine line here with this in regards to big processing lines, the Q labs have a test for this actually, but in my experience, when a lab is geared more towards one make of film, it might not be best for another...it has little to do with skimping on washes, and more to do with what their primary film & aim points are. A lab that makes great Ektachromes, may not be tuned up to make great Fujichromes...there isn't a right or a wrong here, it's just the way things are. It could be a problem with the latter steps like pre-bleach, bleach & fix. But, in this case, I'd say to talk to the lab manager if you have a problem, they would know their porcess better than anyone else. Like I said, +/- 10 cc's and +/- half stop are considered to be normal...that's why people use CC filters. You need to be using a lab that runs plots & control strips on every run, or at least at set times during the day. E6 is almost like a living thing, a very finicky process and it's a science almost keeping it in control in a big lab, or even in a small one...