These are good questions. It depends on the effect you're after, and the problems you're trying to address. In the film days, grain was inherent to the film area on which you were recording light. That is, the size of grain "particles", if you will, was fixed relative to the size of the film. So if you made an enlargement, the grain particles got bigger. The bigger the enlargement, the bigger the particles. Camera Raw 6's grain simulation mechanism currently works in that manner, i.e., relative to the original image capture size. So for a given parameter setting of the grain sliders, if you make small prints, you get little grain; if you make big prints, you get big grain.
If you wish to apply grain as a way to mask resampling artifacts (e.g., during substantial enlargements), or to simulate some aspects of recording on a much larger format (thereby requiring less enlargement from the original capture) ...
... you can do this also with Camera Raw 6, but it'll take an extra step. You'll need to perform your preferred enlargement and output sharpening (e.g., in your case, you say you prefer bicubic smoother followed by your custom sharpening). Then, feed that result (say, an intermediate TIFF) back to Camera Raw 6 and apply the grain. The grain, then, effectively becomes your last step prior to output.
Chan, thank you very much! I will try it soon.
One questing remains: Can this same type or quality of grain be added as a last step in PS CS5? Or is there a real benefit to ACR's quality and or "type" of grain justifying the going back to ACR as a last step?
There are certainly many ways to add grain simulation. ACR 6 provides one way to do it. You can also do it via plug-ins in PS CS5 (there are some very nice third-party plug-ins), as well as various home-grown recipes and methods. You will certainly have more flexibility if you do it in PS CS5, because of the ability to fine-tune the blending, use layer masks, etc. But which is the "best" approach? I cannot answer that for you. The nuances of the quality and the results are really only something that you can answer, for your own work and stylistic preferences. I encourage you to experiment, but the suggestions I've provided should help you to get started.
Excellent. Thank you.
I posted this a long time back, and now that I have done quite a few jobs (landscape
galley prints for myself and other clients - I do photo retouching professionally) I have to say that I really like the grain simulation in ACR. Once the enlargement is finished, sharpened and all that, I make a copy of it (Tiff) and send it through ACR and add the desired grain texture.
I just finished a 70" landscape for a client (on FujiFlex poly paper using the Oce Lightjet) at 200 ppi. I used ACR grain on a layer at Amount 500, Size 18, and Roughness at 35. Then once that grain layer was in Photoshop as a layer, I graduated it into the scene at about a 30-40% opacity to meet the images needs (of mainly disguising artifacts and creating an illusion of more fine detail but not creating a "graininess" look to the image) and erased it from the sky entirely. I viewed the image mainly at 50% but would also do some evaluation at 100%. Having the luxury of being a professional photo retoucher and having a clients images going to gallery almost daily has really allowed me to experiment with both PS grain and ACR grain techniques, and I can say I am impressed with ACR (as I always am).
Deleted by poster—this post made no sense due to a quirk in the forum software.
Glad you like the grain. Adding a bit of tooth to the image is not always bad thing ...
In this context, it's worth repeating that the best grain management software EVER was and remains the set of plug-ins in the Grain Surgery 2 software: Remove Grain, Add Grain, Match Grain, etc.
This works only on PPC machines or under Rosetta, as its developer, Visual Infinity, was acquired by Adobe and promptly killed. Subsequent promises by John Nack and other Adobe staff to look into possibly integrating that technology into Photoshop or offering an updated set commercially remain unfulfilled.
One clear casualty of unfeathered corporate greed to the detriment of the consumer—and one more reason to stick with CS4 and a PPC Mac.
Wo Tai Lao Le