improving 8x10 b&w negs contrast

[martin_frank]

Hi everyone,

I've been using a 13/24/28 turner reich lens on an 8x10 camera with

hp-5 film developed with btzs tubes in ddx but despite excellent

sharpness even with the single 24" element, the negs lack contrast,

even when trying to concentrate my ddx developer more than is

recommended and increasing my developing time.

Any suggestions? Should I just use a modern coated lens?

-Thanks,Marty

[richard_ilomaki]

Martin.

 

The usual way to increase contrast is to extend the time in the dev., usually by up to 50%, not the concentration. How long did you extend the dev time? Is your thermometer close to accurate? Does it happen with another batch of developer- perhaps it is contaminated?

 

You could also try a developer with inherently more contrast; one containing more Hydroquinone for instance.

 

Is the lens foggy or fungus-y(sic)?! Check this by looking through it obliquely toward a good strong light source, and compare it with a known clear lens. Any fog or fungus will be evident. Is it a coated lens?

 

Good luck.

 

Cheers

[richard_ilomaki]

PS Is the film out of date? Is the film base dark? Is there a light leak in the bellows?

 

Cheers again

[lee_carmichael2]

several things could be in play here. it might be that the film (hp5+) may not be able to respond to the development you are giving it. HP5+ is a film that does not respond greatly to expansion. For normal brightness ranges it is as good a film as there is. The lens coatings may be at fault. The developer may not be able to increase the contrast given the amount of developer that is in the tube and the number of square inches of the film. Might be one and it might be all or more but without really knowing that is what I would look at.

 

lee\c

[robert_walsh1]

You should also be aware that the base plus fog for this film is high relative to

other films e.g. trix. This will also lower your contrast range by giving you

higher density values in the shadow areas.

[andre_noble4]

I'm thinking: 1)Underexposed and 2) Premature developer exhaustion

[frank.schifano]

Let me suggest something simple. Are you using a lens hood? This can be especially important if the lens doesn't have any AR coating. You might also want to try using a 1+1 dilution of either D-76/ID-11 or XTOL. Results with either of these developers are about the same and very good, with XTOL perhaps giving you a slight edge in sharpness and shadow detail. I don't know how much solution your BTZS tubes hold since I use an HP Combi plan tank for my 4x5 sheets, but you'll need at least 125ml (150ml would be better for HP5+) of stock solution for these developers to make sure it won't exhaust before the film is developed to your satisfaction.

[jay_de_fehr]

You might have a slow shutter, resulting in overexposure, or inadequate developer solution volume, or any of the other possibilities suggested by others, or some combination thereof. I shoot HP5+ (Arista 400 professional) in 8x10, with a Turner/Reich triple, and develop in ABC Pyro, and more recently Pyro-TEA, and get plenty of contrast, even in flat light, after I fixed a few pinholes in my bellows. As evidenced by the growing list of possibilities posted here, leck of contrast can be symptomatic of a wide variety of chemical, equipment, and technique problems, and tracing it can be frustrating. Your negatives are your best clues, so analyze them carefully, and logically, and address the possible causes in a methodical way until the source(s) of your troubles is revealed. Good luck.<div></div>

[brian_ellis3]

Older lenses tend to produce less contrasty negatives than modern lenses. I forget why that is, possibly because they often are uncoated and so flare is more of a factor. As others have said, increasing development time will usually increase contrast because the increased time has disproportionately more effect on the highlights than it does on the shadows. The shadows are pretty much fully developed in the first half of the total development time, the highlights tend to continue increasing in density with increases in development time.