How do I know when my negatives' density is correct?

[chris_hutchins]

Hi,

 

I've not been developing my own films long and have a had a few

disasters and a few good rolls along the way. Of the rolls where I

didn't make some fundamental error I have got a range of different

negative densities. For example, of the last two films I developed

(both hp5@400) one roll has edge markings that are absolutely black

and the other has marking which are more dark grey. (I am ignoring

the actual image as one roll was taken on a sunny day and has much

more contrast.) Both print fine (in my limited experience!) so which

of these should I be aiming to repeat?

 

Thanks in advance,

 

Chris

[conrad_hoffman]

Edge markings are a good indicator that the film has been developed, regardless of whether it's been exposed. As a measure of development, they're near to worthless. Edge markings only have to be legible, and there's no rule that says they have to have a certain exposure or density. Go by what your negatives look like- do they have density and detail in the shadows, and are the highlights easy to print on a mid grade paper?

[neal_wydra1]

Dear Chris,

 

The Kodak Black & White Darkroom Dataguide has a nice set of examples for negative densities.

[Aoresteen]

Chris,

 

Density depends on the subject color. Black items will have less density than things that are white. It's impossible to tell what proper density is by looking at a negative on a light table.

 

Years ago I learned how to make a proper proof. A proper proof is made by exposing the contact print for the minimum time to get a maximum black through an unexposed frame of film.

 

For my enlarger head height, lens at f/22 and ILFORD MG paper with a #2 filter, my HP5 negatives need 25 seconds. When I proof a roll of HP5 this way, under exposed frames and over exposed frames become very easy to see. I don't worry about measuring the density, I simply make a proper proof and I know which neagtives to keep & print and those to toss.

 

Get Fred Picker's book Zone VI Workshop:

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2228&item=6962344516&rd=1

 

He makes it very simple.

[lex_jenkins]

At least two websites I've seen have a series of negatives that clearly demonstrate the effects of various exposures and development times. Unfortunately they're bookmarked on my personal computer, which is in storage at the moment. Perhaps someone else can recall and post the URL for one of these.

[kev]

You need to test your negatives. Zone test for z1 and z8.

 

Use densitometer if you do not have one you could use a spot meter but not as accurate or you could print for max black and max white off the z1 and z8 test negs.

 

That is the only way to know what your index is and your dev time. Other than that you are just guessing.

 

Here is a link that will explain it without a densitometer.

 

http://www.zone2tone.co.uk/testingm.htm

 

Also depending on the developer you are using I am getting an EI of 200 with HP5. N = 200, N+1 = 320 and N+2 = 400. HC110 1:45 @ 68F. As far as time you really need to test it with your equipment and lenses you are shooting.

 

Also expose for shadows and develop for highlights. Key is consistency.

 

Then when you print you print for highlights and see where the rest falls. Always start with a low contrat and move your way up. But again the highlights are key to the proper exposure.

 

http://www.sbccphoto.org/show_tip.asp?ID=6

http://www.apogeephoto.com/mag1-6/mag2-5js.shtml

 

If you have any question drop me an email.

 

Hope this helps...