Different Color casts in consecutive frames in same strip of film . Processed C-41

[lhalcong]

Hi Experts, what am I doing wrong.? or maybe not me, but what gives in this case ?

This a photo shoot Florida Beach at Sunrise. I am baffled. This roll of film is Fuji 400H , (a fresh roll) and kept in fridge before exposing. Frozen for two weeks after exposing and before processing. If this was a processing problem on my side, I am sure all images would have had a similar problem. right ? But the different color casts in consecutive frames is baffling to me. See attached scanned film frames. IMG027 has the correct skin tones. the next frame IMG028 has a cyan cast, and finally IMG030 two frames down in the same strip has a magenta cast. same roll of film. is it possible for that to happen or something wrong with my scanning process ?

Shooting Conditions: Note that the shots are very similar close ups of the girl and the lighting condition should have been the same on her for the three shots. I used a Canon Speedlight 550EX in a small softbox with silver interior , and a silver handheld reflector on the opposite side to fill in the right side of the girl. The shots are only a few seconds apart from each other.
Scanning process: the strip of film was scanned without applying any corrections so the casts are exactly as they show. Most of the other frames have a cyan cast.

I dont know how to verify with naked eye if these color casts exist on film by just looking. the heavy orange base of the negative film is not something I am used to analyze, but I can try with some tips if provided.


Note: I know it would be easy for me to correct in several ways, with scanner adjustments, or even in the printing process, but I am extremely curious to understand if this is actually possible to happen and what causes it. so to avoid in the future.

thank you again.

 

[MattKing]

It is the scanner and scanning software.

Most scanning software tries to automatically adjust itself in response to each negative - any "corrections" you apply are put in place after those automatic adjustments.

It is similar to using cameras set to automatic, or the old school minilab printers in the days before digital.

Some programs allow you to turn off the "automatic" functions, and then apply adjustments yourself.

 

[lhalcong]

Uhhm ? that bites. I don't know that this software allows me to shut this off.
ok, will check on that. but to keep the mood in the analog world so the moderator do not shut us off, how would you go about verifying that the film frames are all ok and they dont have color casts. I mean regardless of this case.
before actually going into the enlarger printing process or maybe during it.

thanks,

 

[MattKing]

Uhhm ? that bites. I don't know that this software allows me to shut this off.
ok, will check on that. but to keep the mood in the analog world so the moderator do not shut us off, how would you go about verifying that the film frames are all ok and they dont have color casts. I mean regardless of this case.
before actually going into the enlarger printing process or maybe during it.

thanks,

In my case, the only analog way to verify the quality of a colour negative is to print it. A long time ago, when I was doing production colour printing, I might have been able to do more with just my eye, but I would still have resorted to printing them.

If you are an experienced colour printer with a densitometer, there are some other things you could do.

Frankly, however, I would suggest you just use the digital tools you have available to you. If it is a relatively straightforward job to make the image look appropriate, and if the corrections aren't huge, and there are no apparent problems with crossover, the negatives are probably okay.

 

[Arctic amateur]

Vuescan will let you scan without any automatic corrections, if you can figure out the correct incantations in the user interface. You can try the demo version for free. It will watermark your scans to death but you will be able to check whether the scanner software is actually to blame for the color shifts.

 

[ctsundevil]

It's interesting that this question came up today. I was printing 4 rolls of Ektar and one roll of Portra 400 yesterday and the Ektar had a magenta cast on about 60% of the frames. The Portra had no color cast. I shot them on Monday, developed them on Tuesday and printed them on Wednesday. I print everything in the darkroom. It was very strange. I've never seen this before.

 

[polyglot]

Definitely the scanner software. Get VueScan and follow the instructions in my FAQ for C41 scanning. It will come out perfectly consistently and (if you desire) accurately.

If you want to verify that the frames are all of the same colouring (seriously, there is no mechanism for them not to be), then you can:
- make an RA4 contact sheet of the roll, or if you lack the colour chemistry,
- scan multiple frames as a single larger image (e.g. in a flatbed), which will force the software to apply a single filtering setting.