Why more dust on colour neg vs. transparency or B&W?

[DK Gibson]

Why is it I seem to get far more (at least obvious) dust spots on my C41 negatives than on either transparencies or B&W negatives?

I know the dust doesn't quite show up as badly on E6 film because it's black not white. But comparing C41 negs to B&W I always seems to find far more spots on the colour (especially when they are scanned and I look at them in detail).

This was quite apparent recently when I shot some colour negative and B&W at the same time - loaded and unloaded in the same conditions.

Only difference was the colour went to the lab and the B&W I did myself. On scanning both sets of film it seems as is there are far more spots and bits of dust on the colour film?

I've always tended to find this was the case in the past too - it's not just this batch (even when the colour went to a couple of different, very good, labs)

Any ideas?

[Bruce Watson]

Possibly your color film generates more of a static charge than the B&W.

[Paul Schilliger]

Dust on transparencies is seen as dark spots, but on prints from negatives they are seen as specular white spots and much more visible. That's the reason I avoid negative films as much as possible.

[Paul Schilliger]

As you can figure, I didn't read your post very carefully...

[Ralph Barker]

I have come to believe this is the dreaded color corollary to Murphy's Law. More dust jumps onto color negative film just because the color prints are far more difficult to spot. If our ears were more sensitive, I'm convinced we'd hear the high-pitched evil cackles of the dust particles as they leap to their death onto our film. ;-)

The only color negative film I shoot now is Fuji NPS160 in QuickLoads - almost no dust if you keep the inside of the camera reasonably clean.

[Leonard Evens]

I develop my own b/w film and I take my color negative film to commercial labs---mainly Lab One in Chicago. I don't see any signficant difference in the amount of dust between b/w and color negatives. Originally I had more dust on my b/w negatives, but I reduced that significantly by improving my technique. I have one or two obvious spots at worst, and sometimes I have none. Of course under significant magnification after scanning, I find more spots, but that is to be expected. I usually don't spend more than a few minutes spotting my scans.

Perhaps your lab is not doing a very good job.

[bob carnie]

My guess is you process your black and white film in a one shot process and do not reuse your chemistry. whereas colour film in labs, are generally done dip and dunk process with replenishment, what may be sticking to your colour film is the result of thousands of other rolls processed before your film hitting the developer. I run one shot c41 on my jobo for my colour as well black and white and do not see the increase in dust on colour over black and white. I imagine as Leonard stated , that your lab may indeed may not be doing a very good job.

[Al Seyle]

I shoot 6x9 EPY 120 in a Calumet adapter, pro lab processed and sleeved: Little to no dust. Load the same holder with any C41 film, same lab: Much more dust. Always has been worse. Is there more static charge with color neg that transparency film? I'd like to know, too.

[Alain Briot]

The best way to remove dust from film (any film, neg, slides, etc.) is with the Kinetronic Anti-Static ionizing air gun:

http://www.kinetronics.com/cgi-local/SoftCart.100.exe/online-store/scstore/iag.html?L+scstore+wzvd0130ff038e03+1119638193

They also have a canned air model:

http://www.kinetronics.com/cgi-local/SoftCart.100.exe/online-store/scstore/cai.html?L+scstore+wzvd0130ff038e03+1119388863

This is what I now use exlusively prior to scanning and it has turned a one to two hour spotting task into a 10 minute job. This unit removes dust like you wouldn't believe. I use the model which connects to an air compressor, thereby saving the cost of canned air cartridges. The $300 or so price tag is a small price to pay for saving both my time and my sanity.

Alain

[ronald moravec]

Bob Carnie is 100% correct. One shot chemicals including fix for b&w and a Jobo one shot process for c-41.

One must be clean with filtered water and air in the film process and drying area. Once dirt dries in the emulsion, there is no way to get it out.

[Paul Metcalf]

You really can't verify the source of the spots by looking at scanned images. You've introduced at least one more source of spotting (the scan process) in doing this. You need to look at the negatives and transparencies with fairly high power (15x) to ascertain the source of the spots (and in fact, may not be dust but issues with chemicals and also with manufacturing). Sources of spots on negatives and transparencies include scratches (even pinpoint scratches), air burst from chemical processing, debris from manufacturing and packaging at manufacturer, chemical contamination, and yes, dust from loading, exposing (inside bellows), unloading, processing, drying, printing, scanning, etc. etc. Whether or not the spots are clear or black, on the negative or the print/scan, and what shape and size are all indicators of the source.