a sharp grain

[john_frink]

Whenever I print an image at large sizes, like 30x40, I have some

problems that the grain of the negative is not sharp, although I

adjusted maximum overall sharpness. I like images that are a little

bit grainy, I use tri-x with hc-110, I tried ID-11 once instead, but

with no better results. The equiptment cannot be it either. What to

do for sharp grain dots?

[scott_eaton]

A glass neg carrier fixes the problem.

 

Soft grain in large optical enlargements is most likley caused by your neg flexing during exposure.

[john_stockdale2]

As has been pointed out, the negative flatness is crucial. Assuming that your neg flatness is not absolutely perfect, can you get the sharp grain you're looking for on *part* of the print? If you can, then the enlarging setup is the problem (flatness, geometry, lens problem etc).

[m0002a]

You didn't say what size negative you are using, but an enlargement that size may be outside of the usable magnification range for most enlarging lenses. To help alleviate this, use an aperture of at least 3 stops closed from wide open, even if it makes for long exposures. But I would not exceed stopping down more than 4 stops to avoid diffraction limitation. If very large prints are your norm, you might want to look into one of the Rodenstock Rodagon-G lenses that are optimized for such prints.

[john_hicks___]

To begin with you need a properly-aligned enlarger, a glass neg carrier, a good lens suitable for the repro ratio you're doing used at optimum aperture, a good grain-focuser magnifier and an enlarger that's well-braced against movement and vibration.

 

Once you've satisfied those considerations you've eliminated the equipment as being the problem.

[george_paltoglou]

I think Mark has a useful idea. Stopping down the enlarger lens as much as possible will increase the depth of field (or should that be depth of focus in this case?) just as it does with a camera lens. The sharpness of the grain would be a trade off with the lower optical qualities at small enlarger apertures.

 

George

[christian_harkness]

John, I am puzzled by your original comment, 'The equipment cannot be it either. ' Could you explain that? I am asking because my first reaction was, it's the enlarger, and of course, most of the above posts address 'the equipment.' I think a little more detail would be helpful.

 

chris

[tom_menegatos]

I think John means 30x40cm? Which isn't all that big.

<p>

In addition to the suggestions above let me make the following.

<ul>

<li>Make sure there is no vibration on your enlarger during exposure. When you have the head high up on the column it will be less tolerant of vibration.

<li>Try covering the lens with your hand or something to shield the light just before the exposure so that the negative will heat up and pop before the exposure and not during. That is if you aren't using a glass negative carrier.

<li>For precise focusing make sure you use a similiar sized sheet of paper on the easel to place your focusing guide on.

<li>It might be your negative. Some developers soften the edges of grain.

</ul>

Also, like others have said, check your alignment and lens too.

<p>

Tom

[john_frink]

Sorry for puzzling you all a little bit, I am not so really firm with english. But thanks for the answers. What I meant with the equiptment, is that the (small-format-)negative is laying in a glass negative carrier, the lens is an apo-rodagon, and the paper (40x30 centimetres and more) is kept in a frame, pressing it down. Maybe it is the development of the negative itself. Or maybe it is something totally stupid ;-)

[pat_krentz]

Use a pyro developer. Pat

[Troll]

30x40 cm (12x16 in)is beyond the size that 35mm Tri-X negatives will produce sharp results, no matter what developer and equipment you use. Suggest that you try a slower film such as Ilford FP-4+.

[john_hicks___]

> (small-format-)negative is laying in a glass negative carrier

 

But!!

 

Have you aligned the enlarger using a tool of sufficient sensitivity (Versalab Parallel, Zig-Align etc) and is the enlarger rigid enough or wall-braced?

 

It doesn't matter how new or old the enlarger is or what brand it is, if you haven't aligned it or checked its alignment then take it as an article of faith that it's not in alignment.

 

Also check for vibration sources such as a cooling fan, air-conditioner, trucks on a nearby busy street etc.

 

You should use the lens about two stops closed from wide open; wide open or stopped down too far will decrease sharpness.