WE haven't had much to say about Diffusion Disks because they have been speaking for themselves, but there are a lot of very good things we can say about these disks and there is now a new size that is suitable for use with smaller portrait lenses than the original disks were made for.

The new disk is the No. 0 size and is suitable for lenses of from 2 to 3 1/4 inches in diameter. There are two of these new disks, A and B as in the larger sizes.

The A disk gives negatives of ample sharpness yet the lines are pleasingly soft. No one could object to the very conservative diffusion produced by this A Disk vet it is sufficient to eliminate much of the retouching that would otherwise be necessary.

The B Disk gives considerably more diffusion but does not go to the extreme. There is no pattern or objectionable fringes that suggest halation - just a pleasingly soft effect that is well suited to brilliant lightings and that is always uniform - that can be produced time and again with the satisfaction of certainty in results.

The question has been asked: "Why not buy a large disk and use it on lenses of all sizes?" and just here we would like to correct any wrong impression of the adaptability of one disk for all sizes of lenses.

The diffusion produced by these disks is due to a series of circular grooves which are ground or, more correctly, polished on their surfaces. The center of each disk has a circular spot in which there are no grooves so that a sharp image is formed by the light which passes through the center of the disk and lens and a diffused image by the light passing through that portion of the disk and lens outside of the center area.

Naturally, then, if a large disk were properly centered on a small lens, only a part of the diffusion producing area of the disk would be used and there would be very little diffusion. For this reason the disk should be as nearly the size of the lens as possible and if the lens has a hood of considerably greater diameter than the lens itself the hood should be removed and a disk approximately the size of the lens used.

Soft focus lenses produce the greatest amount of diffusion when used wide open and, as a rule, must be stopped down, necessitating a longer exposure if a fairly sharp result is desired. With the Diffusion Disk, however, the lens can be used wide open and the disk over the lens does not increase the exposure. Stopping the lens down will decrease the amount of diffusion but this is not at all necessary. If the B Disk gives too much diffusion, use the A Disk.

Portrait Film Negative, Vitava Print From a Demonstrator's Negative.

Portrait Film Negative, Vitava Print From a Demonstrator's Negative.

The smaller size of the No. 0 Disk will also adapt it to many lenses which are now being used for enlarging. The disk will be found much more efficient than wire screens or other materials used over the enlarging lens to produce diffusion because all of these devices increase exposure while the disk does not.

Make the negative sharp or make it diffused - make the enlargement sharp or make it diffused. And if you choose to vary the amount of diffusion in enlarging, make part of the exposure with the disk in front of the lens, remove the disk and finish the exposure. Practically any result you desire may be secured in this way.

Eastman Portrait Diffusion Disks have really been a great help in enabling photographers to produce uniformly good, soft focus portraits and in making sane diffusion popular with the public. With the new disk the various sizes of portrait lenses are practically covered. With the Adjustable Holders, Diffusion Disks may now be used on lenses of from two to five and five-eighths inches in diameter.

The prices are as follows: No. 0 Eastman Portrait Diffusion Disk, A or B, $5.00; No. 1, A or B, $6.00; No. 2, A or B, $7.50. A Disk Holder is made for each of the three sizes of disks and these are adjustable to lenses of various sizes. No. 0 Adjustable Disk Holder for lenses of from 2 to 3 1/4 inches in diameter, $3.00; No. 1, for lenses of from 3 to 4 1/2 inches in diameter, $4.00; No. 2, for lenses of from 4 1/2 to 5 5/8 inches in diameter, $5.00.

Ask the photographer who uses Eastman Portrait Diffusion Disks what he thinks of them. Use them yourself and see what your customers think of the results. They may be more favorable to diffused portraits than you imagine. It doesn't pay to assume that the public knows nothing about such things. It is your business to show the public the new things. Don't wait for them to ask you for the kind of portraits other photographers are making.

You have been looking for something different - something distinctive - something to give a new note of quality to your best portraits. You will find it in the new paper - Vitava Athena - "Old Master" surface.

Portrait Film Negative, Vitava Print From a Demonstrator's Negative.

Portrait Film Negative, Vitava Print From a Demonstrator's Negative.