Topic: intensifier - does it work ?

[al]

I shot a roll of HP5 at a family wedding with a diana on a wide aperture. When it came to developing it, I remembered how sunny it was on the day and thought I'd try to be clever and pull the processing a bit, as my negs come out a bit heavy normally anyway.  There wasn't any info on the developer about pull processing HP5 so I used a bit of guesswork and knocked a minute or so  off the 6.30  time.  Oh what a clever boy I am eh?

The negs came out painfully thin 

(then I remembered that although it had been a bright day later on, these shots were taken in a shady churchyard before the sun really got going !)

I managed to get ok-ish scans out of them, but it'd be nice to get a bit better.   Before I splash out on some chemicals, have the experts here used intensifiers before?  Will I get any benefits seeing as I won't be doing wet printing, only scanning?

[Francois]

I've never had to intensify but from everything I've read, it does work.
It's made specifically for under-developed negatives. It doesn't work as well with underexposed film.

When you shop for an intensifier, you will notice there are many kinds. Some are proportional (they boost all tones equally) while others are not.

The fun thing is that they can be used in bright light. You process by inspection and stop everything when the film is to your liking. You do get bigger more clumpy grain...

[al]

OK, I finally got some intensifier to sort out my under developed negs.   I'd hesitatited buying from one of the usual online photo suppliers until I had something else to order as the postage charges are so high, but then a bargain came up on ebay so I went for that instead.

The thing is I now know there are two common types:

1) chromium  intensifier which bleaches the image which you then re-develop in paper developer, in normal light until you're happy with the density

2) "red" intensifier which changes the colour of the silver image to a red compound to improve the way it prints on blue sensitive paper in a conventional print process.

The stuff I got was the red stuff.  The thing is I scan my negs, so I have the suspicion that it won't help me a great deal.  It's a long shot but has anyone else ever used this stuff?  does it simply redden the image or is the image also darkened?

I guess I could try to fake "blue sensitive paper", by scanning in colour then in photoshop dropping the red (and green) channels? But something tells me this isn't going to make any difference. 

..... silence...... 

Looks like I'm setting myself up here for another experiment doesnt it?  Oh well, I'll post the results when I've done a test. 

[al]

I've never had to intensify but from everything I've read, it does work.
It's made specifically for under-developed negatives. It doesn't work as well with underexposed film.

I think that's the issue I have here.  I pulled the processing and shouldn't have.  Also when I hold the negs in a bright light and look across them, there's a really good reflected positive image (a great trick which I hadn't noticed before) which appears to have better detail than the actual scans.

When you shop for an intensifier, you will notice there are many kinds. Some are proportional (they boost all tones equally) while others are not.

Wish I'd have read your post first!

[Ed Wenn]

Dredging this one up from the dead:

Al (or anyone) did you get very far with an neg intensifier? I may have need for one as I've had a couple of sets of thin negs due to a silly processing mistake at home and the images look good enough to perhaps spend a bit more time trying to rescue them. I'll be scanning my negs, not printing them in the jazz trad style, so will need an intensifier which will work best under those circumstances.

[gregor]

never tried an intensifier, though selenium toning negs can produce some usable and interesting results on thin negatives.  You have to keep a sharp eye on them though, especially if they are 35mm negs. You can 'recover' about 1 stop...

There's probably a bunch of web resources on the process...

[LT]

the problem with selenium as an intensifier is that it only stretches the tonal range that is present.  It tends to work on the more dense parts of the neg and does hardly anything for shadows.  So it wont boost overall density.

I think the chromium is the one for the job as it works across the tonal range - but as Francois says above, there needs to be some hint of density in the shadows for the intensifier to work on  - you dont get something from nothing.

Silverprint have it here http://www.silverprint.co.uk/ProductByGroup.asp?PrGrp=55

[Francois]

Bit you do always get some massive clumping grain

[Ed Wenn]

Thanks for the info everyone. Very much appreciated as always. I'll re-scan some of the worst affected images with Vuescan and see if I still need to go down the route of becoming more intense.

 

[al]

I never did try it... I also think I bought some chromium intensifier too, no idea where I put it though!  I found that although the negs looked almost clear, except when you looked at them at a very steep angle, almost looking across the neg, you could see the image the nice and clear (and in positve, strangely).  This gave me hope that there was something there in the emulsion that could be developed further. Just never did it!