How to pull develop 2 stops out of C41 film

[rcmartins]

Just to bring a follow up. I have developed all the film and made some prints. As pretty much everyone stated, the two stop overexposure was extremely well handled by the Fuji NS160. I developed as usual with the tetenal 5L kit and used the 1-4 film dev. time: 3m15s.If anything, there was a slight blue tint on the negs, at least when printing on RA-4 paper (optical), but a very, very light tint that probably can be attributed to something else, like mixing shadow with flash (in some others, like the one I am placing here as an example, I also had to mix fluorescent bulb lighting). I did not notice any particular increase in grain.
In several of these photos, and the one I am putting here as an example I did it too, I made the shot firing several times the shutter thus integrating the light from the several exposures. I did it to accommodate the recharging time for the batteries of the flash unit I was using. If I hadn't done this I wouldn't be able to use as much flash. In terms of light it came out as I wanted it but what I notice is that the negative is blurred. It's not noticeable here, as the resolution is too low, but if I enlarge it 15x or more, it shows. As much as I tried to not move the camera, the force needed to cock the shutter must have also moved slightly the camera. The photo that I show here had the shutter fired 6 times. I will have to find a way to fix better my camera to the tripod head, or better fix the front panel.
The sheets went through the airport hand luggage security check x-ray machine twice. No harm as far as I can tell.
Thank you everybody for your help.
raul

[vinny]

Over exposure decreases apparent grain.

[Drew Wiley]

I certainly wouldn't mess with the development, for reasons already stated. The neg might come out a bit dense, or maybe just fine. Hard to say exactly how well it will print without trying. A lot depends on the original scene contrast. The only darkroom way to fine-tune contrast on Fujiflex is via some kind of registered silver
mask to the neg. But most of the time that isn't necessary. Hard to say in this case. Depending on the subject, you might be able to simply dodge and burn your
way through any problems. I wouldn't worry too much at this point. That particular film has a fair amount of wiggle room.

[Drew Wiley]

Oh, sorry... I just noticed you already posted. Looks like you succeeded to some extent, though fluorescent lighting is always something of an issue.

[rcmartins]

Drew, no problem and I appreciate all the help. The density of the negs did not accompany the overexposure. In particular, while the overexposure was 2 stops, while enlarging the exposure was just 1 stop over what would be required for an equivalent neg. This is obviously a rough approximation since it depends on the overall lighting range of each negative, but I am confident that I am not far off with this estimate.
To control the contrast I am using a CRM (Contrast Reduction Mask) in a registered carrier. For these negatives the highest density of the mask is around 0.15. I then also use a SCIM (Shadow Control Increase Mask) to make the print more punchier.
As for fluorescent, indeed it is an issue, and quite a lot of paper is wasted while trying to find an equilibrium point that suits my taste. Its fun but it isn't cheap.
raul