Help to reduce moire/dot effects when rephotographing B&W half tone images in books.

[matt_t_butler]

These days one can apply Gaussian filters in image processing to reduce the moire and dot patterns when photographing early 1920s -1930s B&W images in books and magazines.

To achieve this during the actual copy stand macro photography and reduce post production time ( ..... imagine re photographing the contents of many early photo magazines).

Is there a better way than the simple technique of shifting  the focus from sharp to soft as shown in the reference photos below?

I prefer to work with filters 'in-camera' and recall a special filter was marketed way back to assist in this process.

EDIT:

Pix: 1) Original - photographed CLEAN

Pix: 2) Same but with slight focus shift

Pix 3) Detail of both 1 and 2

 

 

Edited December 16, 2023 by matt_t_butler

[JDMvW]

On 12/15/2023 at 7:16 PM, matt_t_butler said:

s there a better way than the simple technique of shifting  the focus from sharp to soft

Well you can continue to pound the heck out of a half-tone image by softening the image and then upping the contrast "to 11". there are also tools for hardening edges in PS.

[matt_t_butler]

@JDMvW  Thanks for that info.

In the meantime I managed to speak to photographer 'of a certain age' who opined that the 'special filter' I was enquiring about, appeared to be a diffusion filter with a contrast factor. As this glass filter was produced over 60+ years ago, chances are slim of locating one - although I guess there is always a slim chance on eBay.