If the washes are not detectable by the camera, they are most likely too light, and could be repeated to build them up.
This is probably the best way to do washes anyway, so it not over done.
Stand back about 1 meter from your model and see what details/edges/etc stand out clearly and those that dont ... this will give you a better idea of a "good" level for details/panel lines/edges/etc. (good could be translated as my personal preference, so take this with a pinch of salt).
Weathering/depth level
should also be considered depending on what you decide to do with model; Keep on display at home for you and your friends only, posting online, competition, etc
For competition, the one meter rule is a good one, in my opinion.
For last years C4, I rushed to be finished with my Brumbar and painted it quickly under very bright lights in the last minutes and was happy with it. The minute I set it on the competition table, I knew at once the details didn´t stand out enough for viewers. There was an Opel Blitz beside it, and evey line, panel and detail was perfectly visible ... guess which model my eye was attracted to ... and I assume every other viewer and probably judges as well.
See
http://www.plasticwarfare.se/2011/10/c4 ... -vehicles/. My Brumbar is thumbnail 18, and the opel blitz in question is thumbnails 23 and 27. The Brumbar photos dont explain exactly what I mean, as Erik´s camera is both close and of high quality and shows the weathering, but from 1 meter much of this dissapears, but the Blitz images give a good representation of how it looked from 1 meter. Again in my opinion (for what thats worth) this is perfect for a competition. But if you look then at thumb 28, and see the blitz up close, it could be considered to be slightly over weathered, and has used only chipping to highlight the edges consistently which maybe does not look so appealing? Thats why using so many other methods (pre/post shading/dry brushing/colour modulation/etc) can help and not only be limited on washes and chipping to add depth.
Thats what makes the difference for me when I see a great model online or in a magazine .... your see the depth and details, yet the techniques used are not so overdone. This is probably the hardest to get perfect, and has much to do with the viewers own preferences, as it does skill level. Somebody who scratch builds to a very high skill level is easily acknowledged because its there for all to see, but the depth and weathering levels are constantly discussed on online forums as well at competitions and clubs, because sometime we talk apples and oranges, and not everybody is in agreement. What works in a competition does not always work well for up close detail photographs and vice versa, and throw preferences into that mix, you got a real hot potatoe!! Maybe there are those who wake up in the middle of the night screaming over their decisions as well?
Sorry about the long-winded post ... just wanted to give some background to my original opinion. The guy who painted the Blitz is from Denmark, and I have known him via Armorama for many years and this was the first time we met physically. We talked for about an hour on this subject, so you get the idea how hard it is to compact it for a reply in a post! Thanks for reading this far!
