Arista Ortho Unsharp Masks

[pemongillo]

I have been using T-max to make unsharp masks. For several reasons I

won't get into know, I decided to try Arista Ortho for this purpose.

I went into the darkroom last night to start the learning process for

the film. Much to my amazment there is no notch on the film to

assist you in figuring out which side the emulsion is on !! Is this

a defective box of film or am I missing something really important

here ? The box came with no instructions.

 

Also, I plan on using HC-110 or Dektol to develop it. Any

suggestions on dilutions and times for those ?

 

I was also a little amazed at how difficult it was to get the thin

sheets into the Jobo. I'm guessing I will have to use trays for this

stuff.

 

Any guidence would be greatly appreciated.

 

Thanks

Paul

[donald_miller1]

Paul,

The Aristo ortho half tone film may be examined under safelight to determine emulsion side. The emulsion side will be lighter color, the base side is the darker side. Insofar as developers and dilutions, I use Dektol at a dilution of 1-30 for appr. 1 1/2 to 2 minutes to gain a density of about .35 . You will need to determine your exposure times for yourself as they would be dependant on the density of your camera negatives. On my negatives which have a targeted density of 1.20 above FB + fog I usually find my exposures to run in the neighborhood of 18-25 seconds at F8 with my Saunders 4550 XLG as the light source and an enlargement of 8X10 height. If you do other masking such as SCEM or HCEM then this material works very well for those applications as well. For the sharp masks I mix Dektol at a dilution of 1-10. Hope this helps. Good luck.

 

Regards,

 

Donald Miller

[pemongillo]

Thanks Don. So I can look at this stuff under my normal safe light? Don't need any special filter ? If that is true, can I leave the safe light on during the whole process or just briefly here and there as needed ? Sorry, I have little knowledge of this type of film. Didn't know it had all of these "special" characteristics when I started this. My primary motivation is that its cheap and its thin (fits in a normal film holder with the orginial negative, this is too tight a squeez with T-max).

 

Paul

[jim_galli4]

Hi Paul. When I make masks for 4X5 I do it with the safelight on the whole time. I put the 2 films into a film holder together emulsion to emulsion and make several timed exposures on the same sheet for a trial. You can do that by sliding the dark slide further and further out until it's all the way out. So you can get 2,4,6,8,10 sec.s on 1 sheet. Then just watch it in the developer and after a couple of tries you'll see the density you're looking for come up in the tray. Rinse and fix. Then you've got 5 choices to choose from to make the mask how you want it. Then when I use the mask I just register them back to back so the diffusion effect is from whatever those 2 widths are. Actually kind of fun to be able to watch all that happening with a safe light on. However the safe light I use with the ortho is "redder" than the normal Kodak OC.

[al_seyle3]

Be sure to use a dark red safelight for Ortho films--not yellow.

See...

 

www.ilford.com/html/us_english/pdf/safelight.pdf

[donald_miller1]

I use the same safelight for this material that I use for photo enlarging and that seems to work quite well with no fogging noted.

[pemongillo]

Thank you everyone.

 

Paul

[michael_kravit]

Another great film to use is Ilford Ortho+. Remember to use a Red Safelight,

The OC Orange will fog the Ortho film faster than the red. Test your safelight

and know how long you can work with it before fogging.

 

Mike

[d_poinsett]

Hello Paul,

 

I tried using Arista Ortho for unsharp masks but found it that it had too much contrast. It was also rather blotchy. I think this film may work great for its intended purpose (lithographs) and masks which require high contrast, but I found it unsuitable for the continuous tone requirements of unsharp masks.

 

Other comments about using a safelight with Arista Ortho are correct. This IS one of the advantages of using ortho film. I think someone else also mentioned that you can expose this film through the back side. This too is true although you must account for the reduced light reaching the emulsion. And yes, you can tell which side is which under the safelight. Lighter Side = emulsion.

 

I currently use Ilford Ortho+ for unsharp masks and I am very happy with it. I use HC-110(B) for 1:30 min at 20 C. This yields an average G of about 0.5. I could use a little less contrast but so far the 0.5 has been OK.

 

For making unsharp masks, I use the method described by Howard Bond. His system is easy and predictable if you have a densitometer. It can also be done without a densitometer but it is more complicated. His method was described in a couple of his magazine columns and he also teaches a workshop on the subject.

 

I also have Radeka's kit which is great but Bond's approach to determining mask exposure and density is very systematic whereas Radeka's invovles more experimenting. (Radeka covers other mask types as well. It you are really interested in all aspects of mask making, his kit is probably worth getting.)