Green casts on LF negatives?

[m00dawg]

I've been trying to chase down a weird case where I get this weird green cast on my negative. I have only ever seen this in 4x5 and it makes color correcting/converting the negative really difficult (though I've had almost ok results with Negative Lab Pro). I haven't found a common thread yet. It's happened on Ektar and Portra, on multiple lenses, I develop sheets usually 4 at a time and I'll get some which look awesome in the same dev batch so I don't think it's development.

I think it might be underexposure but in one case I shot Velvia and Ektar on the same subject and the Velvia turned out awesome using the same settings (just a stop more light since I was using Velvia 50).

So then I think it might be underexposure plus a low contrast scene, but I've had negatives shot in around the same light which look great. It's weird too if it was underexposed, I wouldn’t expect a cast - certainly not what ends up being a red cast post conversion. I've done a few night shots with Ektar and ended up with a pretty beautiful negative that definitely didn't have any green cast which is why I'm confused as to how it might be underexposure?

I've included a sample negative. For this one I'm pretty sure I underexposed a little bit though I didn't think by a lot. I had other shots taken the same time (last weekend) which turned out pretty great. It has me thinking I should perhaps rate Ektar at a lower speed if it is an underexposure issue, but since Ektar has a bit less latitude than Portra I wasn't sure if I should go down that route.

184737

It's driving me nuts so hopefully someone can school me on what's going on. Color film isn't cheap to shoot in 4x5 heh.

[koraks]

That looks pretty horrible, but a straight photograph of the negative may give more accurate information.
How do you process these?

[chassis]

Something isn't right, possibly multiple things. I'm seeing underexposure, in addition to what may be processing (chemical and post-) challenges. The film base color is not correct, based on the attachment provided.

Regarding exposure:
- How did you meter?
- Which meter do you use?
- How did you rate the film speed on the meter?
- What part of the subject did you meter?
- Did you meter both the near foreground and sky? What were the values?
- This scene is not as low contrast as one might imagine. The sky is likely quite a few stops brighter than the near foreground. This, combined with unknown exposure (aperture and shutter speed), creates the potential for significant underexposure in the near foreground.

If you can provide the following, it will help with diagnosis:
- a phone photo of the negative, as koraks suggests
- please tell us everything about processing
-- tank and equipment used
-- brand of chemicals
-- age of chemicals (are they new? yes or no)
-- time of processing steps
-- temperature during processing
-- agitation during processing

[ioingjorbor]

From time to time I get a subtle green cast on my Portra. Nothing like this tho


Enviado desde mi iPhone utilizando Tapatalk

[m00dawg]

Yeah all valid points! Here we go!

- a phone photo of the negative, as koraks suggests
184743
- please tell us everything about processing
I used a Unicolor C41 kit (am now realizing I should probably try to find a way to do separate bleach and fix but I don't think that's the issue here). Chemicals warmed to 39C in temp controller waterbath (via a custom Arduino, a pump, heater, temp sensor and relay). I also put my Patterson tank in the bath for both the dev and blix steps. Agitation via stirring stick (since the Patterson tanks are a bit leaky I've found). I used a MOD54 with 6 negatives total (4 came out great, 1 was clearly overexposed - I probably left the lens open when I took a shot like a dummy, and then the green one). Standard times (3:30 dev, 6:30 blix, 3 minute wash, 1 minute stab)
-- tank and equipment used
Patterson hand tank with a MOD54, six sheets total.
-- brand of chemicals
Unicolor
-- age of chemicals (are they new? yes or no)
About a month old, kept in accordion bottles and only used to
-- time of processing steps
Dev for 3:30, Blix for 6:30, 3:00 wash, ~ 1:00 stab. Dev may have gone on for slightly longer but the other negatives look good
-- temperature during processing
39C
-- agitation during processing
Stirring stick, no inversions except for the wash. This method seems to generally work well and is far less messy than inversions.

Of note, though this green negative was using my home dev, I've had green negs before from a lab which makes me think it has something to do during image capture. Can a bad film holder somehow cause this? That's the one thing I haven't looked at (if I used the same holder or at least the same brand) though because it seems to be across the whole exposed part of the negative, I didn't think it could be a holder?

[Greg]

In the 1980s (or maybe in the 1990s) had similar results with Kodak color neg. film processed in Kodak C-41 chemistry. We believed it to be chemistry contamination at the time so we just tossed out the chemistry and the bottles and started anew. Next batch of film was just fine. Sometimes just have to throw in the towel and start all over again.

[jnantz]

sorry for your troubles, but i kind of like it !
i am guessing inverted it is a rolling field of brownish grass ?
im kind of a lemons>lemonade, good luck to be crapped on by a pigeon,
tomato tomaahto kind of person ...

hope you get it straightened out if you don't like it ...

[m00dawg]

sorry for your troubles, but i kind of like it !
i am guessing inverted it is a rolling field of brownish grass ?
im kind of a lemons>lemonade, good luck to be crapped on by a pigeon,
tomato tomaahto kind of person ...

hope you get it straightened out if you don't like it ...

I was able to kind of salvage it with Negative Lab Pro (a new LR plugin that, so far, has done a pretty amazing job at colorizing my negs):

184744

You can still see some odd density in the center there. In Epson Scan I couldn't get rid of the red tint without just messing the colors all up, but NLP did ok. The uneven density could be the development though my other negs do not show that from the same run. *shrug* I find when I have the green cast usually the scanner gives me these areas of uneven density. My money at this point is on the holders used, or at least that's the one thing I haven't checked yet. Still would seem odd to me (how could a light leak only leak red?).

You might be onto something, @Greg, although still odd to me it only affect one of the six sheets I developed in the same session. I use accordion bottles at the moment but I'm gonna probably switch over to the 1L SmartWater bottles. A little taller (so may take longer to warm the chemicals) but seems like I can get the air out better with those and they're much cheaper (especially if I can figure out how to do C-41 using a separate bleach and fix over a blix).

Actually on that note I have thought about having a lab run my C-41 instead. No local labs here do 4x5 so I'd have to send it off which seems to get expensive pretty quick, especially when I'm trying to learn (quick turnaround times really help there by dev'ing things myself).

[m00dawg]

Dug through my notes and it doesn't appear to be an issue with a film holder as I used different and known good holders for some of the shots I get these green casts. Still not sure what it is though :/ so the mystery continues.

[Steven Ruttenberg]

I was able to kind of salvage it with Negative Lab Pro (a new LR plugin that, so far, has done a pretty amazing job at colorizing my negs):

184744

You can still see some odd density in the center there. In Epson Scan I couldn't get rid of the red tint without just messing the colors all up, but NLP did ok. The uneven density could be the development though my other negs do not show that from the same run. *shrug* I find when I have the green cast usually the scanner gives me these areas of uneven density. My money at this point is on the holders used, or at least that's the one thing I haven't checked yet. Still would seem odd to me (how could a light leak only leak red?).

You might be onto something, @Greg, although still odd to me it only affect one of the six sheets I developed in the same session. I use accordion bottles at the moment but I'm gonna probably switch over to the 1L SmartWater bottles. A little taller (so may take longer to warm the chemicals) but seems like I can get the air out better with those and they're much cheaper (especially if I can figure out how to do C-41 using a separate bleach and fix over a blix).

Actually on that note I have thought about having a lab run my C-41 instead. No local labs here do 4x5 so I'd have to send it off which seems to get expensive pretty quick, especially when I'm trying to learn (quick turnaround times really help there by dev'ing things myself).

4 bucks a sheet, plus shipping. Just use fresh chemicals for each session and don't exceed the max number of sheets that is recommended.

I used some old partially used E-6 and got wonky whacked slides. Good thing I can go back and redo.

[Steven Ruttenberg]

Looks liked a lense flare right of middle and maybe a light leak, lower left.

[Steven Ruttenberg]

Did you try soaking and rinsing again? Has that color of anti-halation layer.

[m00dawg]

Hmmm I certainly can try that - although wouldn't that show up on the un-exposed edges as well? Those look normal - it's just the exposed area that's odd. The chems were at about end of life in terms of the recommended number of sheets Unicolor suggests, but was in spec. My other negatives came out quite good from this batch (including other Ektar sheets). That makes me think it's not strictly the chemicals, though running it through another blix/rinse stage can't make it any worse I suppose.

I thought about flare - and it does kinda have that look. The weird thing is the last time this happened I exposed a sheet of Ektar (which ended up with a green cast on the exposed part of the negative just like in this case) but a sheet of Velvia right after without moving the camera that turned out rather good (not casts, proper exposure, good color, etc.). If it was flare that would be odd it didn't impact that sheet. Those sheets were lab scanned as well (at Blue Moon Camera as I was visiting Portland at the time - cool place to check out by the way!) In the Portland case I was at that typical beach with the mountain and rocky islands that seems to be a place lots of people take photos. It was overcast and I had multiple negatives end up with this green cast.

Another time I took some shots of the kiddo for his first day of school. In that case, the HP5 turned out great, but both the Portra sheets I used had this same green cast. For all these I didn't see any flare looking at the GG.


In all these cases, except the portrait of the kiddo, it was an overcast day. But that's still weird - the color should shift towards blue not red.

I had hoped it was the film holders (since I never get the green cast of evil on 120 or 35mm) but nope there's no common thread there. Since it was multiple holders (I think even different brands), it would be odd if this was caused by a light leak but...hmm I have an Intrepid with red bellows on the outside - I'm fishing real bad here, but if there was a tiny light leak that was reflecting that color, I might not see it through the GG but the film might? Maybe? Still weird I didn't get a cast of any kind with the Velvia sheets though...I haven't tested the Intrepid for leaks though so perhaps I should do that.

[Steven Ruttenberg]

Bad film? The good sheets plus bad one all came from same lot, not expired?

[m00dawg]

I thought about bad film sheets. With as much as color sheets cost in 4x5, that would be make mildly upset but that could be possible for sure yep. These were freshly bought stocks not more than a few months old and have been fridge stored in plastic bags in my veggie drawer. I went through my entire binder and all told it was:

5 sheets of Ektar
2 of Velvia
2 of Portra 160

Those Velvias I had forgotten about - it was from a beach trip where I was trying to shoot a sunrise and using ND filters (one shot was using Hitech's square graduated ND and the other was a screw on). They have a red cast, which makes sense since my Ektar and Portra negatives have a green cast. I think these beach ones may have been flare. The green cast I got at the Portland beach was during an overcast day though (and my T-Max 100 and Velvia shots there turned out great).

[Steven Ruttenberg]

Color shift? What was exposure time? With nd filters if film sensitive to NY amount of IR you can get a red cast, and flare from light leaks if exposure long enough. I use IRND filters designed to block all uv for digital and film. Did your colors look washed out on velvia with nd filters?

[m00dawg]

Exposure times for all these were short. I can go look them all up but under 1" but likely well under. In the case of the fence one (the one I posted here), it was 1/30 at f32 on my 150mm Fujinon. I DID use a Hoya HTCP on this one, but I've had shots where I didn't use any filter on the lens and still seemed to get this green cast of doom.

I got excited when I realized maybe I just red-scaled it by loading the film in backwards, but alas no, the composition on the negative is correct so I have to discount that. Plus I thought when you redscale you don't get ANY blue when converting? I managed to recover some blue from all the green cast of doom sheets.

The only commonality I can find is the camera. But I mean it's just a box :) And if it was a lightleak it'd be weird it was only on the red channel (which is on the bottom layer of the emulsion?). I plan on testing for light leaks today though just in case.

Super frustrating because I absolutely love shooting 4x5 but yesh I wish I'd at least know the cause. Operator error would be fine if I knew what it was to improve upon. Only thing I can think of is, if it is somehow underexposure, to start rating Ektar at 50 ISO. I'd rather go over than get red casts.

[m00dawg]

I contact Intrepid about it and ended up getting an e-mail back from Max (I think THE Max). He thinks, as some have said here, it might be a development issue though admitted it is odd not all the sheets are affected. It otherwise looks like that to him. So I wonder if maybe my agitation scheme isn't ideal or perhaps that sheet exhausted the developer around it more quickly (more back to agitation). It is odd I got green casts from lab developed sheets though but the fact I don't really see bad BW sheets indicates a chemical issue there as well.

Either way I'm thinking about doing the following:

* Checking for Light Leaks (Max mentioned that leak on the side may be the camera, not the holders).
* Switching from Unicolor to Kodak or Fuji chemicals (larger quantities as liquids instead of power and some can be mixed as needed and I can use a separate bleach and fix instead of a blix)
* Moving away from Patterson/MOD54 to using something like a Jobo tank and use a hand roller (I can't afford a JOBO processor yet) at least for the color film
* For sure shooting doubles for important shots and only developing one of the sheets in the set at a time

I already basically have all the stuff to make a hand roller (no way I'm buying JOBOs WTF overpriced one for $100 - nearly lost my lunch when I saw the pricetag on that thing - it's $2 worth of parts!)

I thought about the SP445 as well but I was going to start testing a JOBO tank for the tiny formats (playing with Vision 3 and ECN2 in 35mm) so once I get that down, I can look at sheets. The perk of the JOBO 2500 for 4x5 is it seems folks have better luck with the thin Rollei IR sheets (lovely film, nightmare to develop in sheet form since they're so thin).

[Steven Ruttenberg]

I use the sp445 and unicolor and have not gotten any green casts. I did get green streaks when I sent my film out. The sp445 is perfect for this. When doing the inversions, do them with the long edge facing you only, never the short edge facing you. There is a video on this from Stearmen. And it is only 80 bucks.

[m00dawg]

Thanks Steven!

Good point (and by the way thanks for all the help and comments on this thread in general!)

How does it fare with scratching and leaks? I wasn't doing inversions for the Patterson because it's leaky and I don't want to get C-41 chemicals on anything (especially the Blix since it's stains). I've seen some YouTube folks using the 445 though and yeah it looks like it could work well. Bonus points that it only does 4 at a time hehe - I like that better because I typically shoot in groups of 4 (mostly for easy filing into PrintFiles).

Only negatives I've heard is that it can scratch negatives and the seal can eventually start to leak? The guy that makes them seems like a pretty cool dude though! Good point!

Oh, do you know if the 445 can do Rollei's thing sheets (like IR)?

[Steven Ruttenberg]

Haven't had issues with scratching. Probably better than tray processing and any system the negative can get scratched as at some point it has to touch the tank, tray, etc. The sp445 has holders that minimize the contact and what is contacted is the non-emulsion side. It will only leak if you don't follow the instructions. Ie, take caps off, fill it, put vent cap on,squeeze it till you see liquid rise in the fill port, then while squeezing put that the fill cap on and make sure both are tight. Then go for it.

[Steven Ruttenberg]

Your welcome.