Getting black blacks with larger enlargements

[thisispants]

Im extremely new to darkroom enlarging, so thanks in advance for your patience.

Basically I've been making 8x10 prints from 35mm negs, and while I'm getting good results, I've noticed that the blacks I get on the larger negatives aren't as black as when I print at a smaller size, for example 6x4.

I assume this is due to the fact that there's the same amount of light being dispersed over a greater surface area. However, the longer exposure times I use for the 8x10 prints look properly exposed, except the blacks aren;t quite as punchy.

I hope that makes sense.

Basically I'm wondering if there's anything I can do to fix it.

Cheers!

 

[Sirius Glass]

Get the right print exposure for the lightest of the whites. Then increase the contrast until the darks are dark enough. For grades 4 and 5, you may need to increase the exposure time.

See Ralph Lambrecht's book, Way Beyond Monochrome, Second Edition, http://www.waybeyondmonochrome.com/WBM2/Where_to_Buy.html. He had been giving free advice on APUG for years.

A shameless plug for Ralph while he is recuperating.

Steve

 

[hpulley]

Same paper? What exposure times? Have you tried exposing for longer with 8x10?

 

[tkamiya]

Well.... if you are making prints larger and appropriately lengthening exposures, larger prints probably do have the same black. However, your eyes may be playing a trick on you.

I've noticed what looks good on 8x10 doesn't exactly look the same on 11x14. The difference is even bigger going from 5x7 to 8x10 for some reason. I've noticed I have to increase contrast a bit (1/4 grade or so) and tweek the exposure time to look "about the same".

There are all kinds of formula on how to calculate exposure time or f/stop when going larger and smaller but I find none of them work exactly as calculated if I go by how the prints look.

 

[thisispants]

Thanks for the link and the replies.
Increasing contrast may be the answer. I used the same of everything (paper, chemicals etc).
I increased the exposure time for the larger image, in fact I did a test strip to completely reassess the proper time.

I used the same contrast filter, so next time I'll try using a contrast filter #4. See how it goes.

 

[tkamiya]

I don't know what filter you used for your smaller ones but don't go overboard. 1/2 grade will make a big difference.

 

[ROL]

Basically I've been making 8x10 prints from 35mm negs, and while I'm getting good results, I've noticed that the blacks I get on the larger negatives aren't as black as when I print at a smaller size, for example 6x4.

I hope that makes sense.

Well, not the way you've worded it. You're expecting the same results from a "larger negative"?

But if you mean that as you increase enlargement with the same negative that print contrast decreases, that may often be the case with 35mm, and can be resolved by uping your print grade – so much as is possible with small formats. This is generally not the case with MF and LF when negatives are thoughtfully exposed – at least I've never experienced it in enlargements going from 11X14 to 30X40. This may be of some help as well.

 

[thisispants]

Ha, yep, you know what I mean.

 

[Bob Carnie]

You are probably getting more flare light as you enlarge, bouncing off things around the easel and such, as well you need to make sure your negative is masked off.
You can get the same blacks as you enlarge, your workflow needs to be tighter though.
I would say no more than a 1/2 grade change is required.
As well , when the print gets larger the scene opens up more , this has an effect of the viewer seeing more into the shadows causing you to think your blacks are not as effective.

 

[ROL]

As well , when the print gets larger the scene opens up more , this has an effect of the viewer seeing more into the shadows causing you to think your blacks are not as effective.

True enough. A richly detailed and composed negative will often begin to "breathe" only as enlarged beyond certain minimum print sizes. It is primarily for this reason that I prefer the process of enlarging from MF and LF sources to at least 16X20 and larger, to contact printing (although contacts certainly have their own sense of beauty).

 

[Bob Carnie]

Me too, I appreciate contact prints but really love 16x20 and 20 x24 from good negs. Easier to print as well.

True enough. A richly detailed and composed negative will often begin to "breathe" only as enlarged beyond certain minimum print sizes. It is primarily for this reason that I prefer the process of enlarging from MF and LF sources to at least 16X20 and larger, to contact printing (although contacts certainly have their own sense of beauty).

 

[Ronald Moravec]

You probably need 1/2 + grade more contrast paper. I always did.