Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Did you pick up that ridiculously big but cheap one on Craigslist a month or so ago? It was at a sign maker's shop downtown and he was moving and didn't want to take it with him. I was on my way down to pick it up when our pressure washer and our AC for the sales offices went down at the same time and obviously didn't make it down to pick up.
I badly needed it for my large screens for posters and all over prints etc. I was kind of doing them in the most low tech way possible and the results sucked, and was trying to build a unit but kept not having any free time. I don't know if it will replace my regular unit for standard screens, but it sure is nice for my big stuff.And like you said, no risk to buying it. If I find I don't really need it down the road it is in fantastic condition and they sell for 5x that or more on digitsmith with some frequency.Now I just need a 3k, 5k, or better light source...
Quote from: Dottonedan on September 03, 2014, 04:19:21 PMI need that old "rule of thumb" info where you x your screen frame size by X to get your light source (distance) for two screens at a time? 23x31's This is for a wall mount exp. I think I recall 40" but that can change based on the screen frame size. Here, we are doing two 23x31's placed horizontal or side by side.Anyone remember what that is?Quote from: Orion on September 03, 2014, 08:51:36 PMDan, you have an in with your comrades at NuArc, bet they could answer precisely...The 1.5 times the diagonal rule came from the days of Carbon Arc light sources, and yes I was with NuArc when we manufactured Carbon Arc Units. The reflector on carbon arc units was as much of an air deflector as it was a light reflector, so as not to affect the light output from the burning carbons. Over the years reflector designs changed to get better coverage at different distances. As an example our Trilight unit that has been on the market for around 15 years and will handle up to a maximum of a 42"x60" screen. The glass to lamp distance on the Trilight is 31". As was already mentioned, increasing the lamp to glass distance will greatly increase the exposure time, which was one of the main reasons for the reflectors that we use today. There is nothing wrong with the 1.5 rule, and if you do increase the distance you will get a little better coverage, but the down side is that it will take longer to expose the screen.Ron HopkinsNuArc Sales Mgr.M&R Sales and Service Co.
I need that old "rule of thumb" info where you x your screen frame size by X to get your light source (distance) for two screens at a time? 23x31's This is for a wall mount exp. I think I recall 40" but that can change based on the screen frame size. Here, we are doing two 23x31's placed horizontal or side by side.Anyone remember what that is?
Dan, you have an in with your comrades at NuArc, bet they could answer precisely...
It will become obvious to new users, but with a set of common screen sizes used, shops with these wall units end up with a series of marks on the floor to which the different light-to-screen distances apply. (of course, a chart relating this one new variable to use along with mesh and emulsion time or light unit figures will be another obvious addition)And yes, I first used these marks with a carbon arc. Flat stock shops I worked typically exposed screens anywhere from "36x48" to 48"x72"
Quote from: RonH on September 04, 2014, 09:33:04 AMQuote from: Dottonedan on September 03, 2014, 04:19:21 PMI need that old "rule of thumb" info where you x your screen frame size by X to get your light source (distance) for two screens at a time? 23x31's This is for a wall mount exp. I think I recall 40" but that can change based on the screen frame size. Here, we are doing two 23x31's placed horizontal or side by side.Anyone remember what that is?Quote from: Orion on September 03, 2014, 08:51:36 PMDan, you have an in with your comrades at NuArc, bet they could answer precisely...The 1.5 times the diagonal rule came from the days of Carbon Arc light sources, and yes I was with NuArc when we manufactured Carbon Arc Units. The reflector on carbon arc units was as much of an air deflector as it was a light reflector, so as not to affect the light output from the burning carbons. Over the years reflector designs changed to get better coverage at different distances. As an example our Trilight unit that has been on the market for around 15 years and will handle up to a maximum of a 42"x60" screen. The glass to lamp distance on the Trilight is 31". As was already mentioned, increasing the lamp to glass distance will greatly increase the exposure time, which was one of the main reasons for the reflectors that we use today. There is nothing wrong with the 1.5 rule, and if you do increase the distance you will get a little better coverage, but the down side is that it will take longer to expose the screen.Ron HopkinsNuArc Sales Mgr.M&R Sales and Service Co.Thanks Ron, for chiming in. Very nice. We were able to narrow down a pretty decent 65lpi holding the 5% dots but given that their standard will be 55lpi, we were spot on at the 305 mesh.