Crude 11X14 Enlarger Mockup...Success!

[John Layton]

Neither of these...instead I will be building an RGB LED light source.

But to answer your question...a few years back I'd tested a similar setup with a large gel filter at the light source vs a "below the lens" filter...and I could see through my focus magnifier the the image quality with the filter at the light source was sharper.

My other concern about using "below the lens" filters for split grade printing is that if the second filter used is not in the same exact position as the first, in terms of its "optical planarity," then the presence of a filters refractive index (such that it might exist) could mean a slightly "out of register" result. This would be more of a (potential) issue, I would think, in the case of using filters with any amount of thickness. Very thin filters, like gels, generally will not have this issue, or at least not to the extent that such refraction would be noticeable.

Edit: of course, the extent of any image degradation noticed in such testing as above may or may not be noticeable in a print, depending on a number of other variables like print size, subject rendering, viewing distance, etc.

[Tin Can]

A couple more photos...showing side/front and side/rear views of the camera affixed to the motorized base. The fixing points are very tight and so the bases squareness (once dialed in and fixed) is maintained throughout the enlarger's travel:

Attachment 245951

Attachment 245952

While this base is great for keeping things straight as well as adjusting distance, its actually not that effective as a focus control...as visible focus changes through such means happen much more slowly and less distinctly than by moving the lens position relative to the film plane. Realizing this was a bit of a disappointment as I'd first envisioned using both the motor and hand wheel as rough and fine focus controls.

Later Edit: with respect to (and out of respect for) ic-racer's comment about focussing with the whole carriage...I imagine that this could indeed be quite effective for my horizontal setup if I had a better loupe. Right now I'm using a Bestwell Microsight...decent loupe but that's about it. If I could find myself a Peak 1...now that might make a difference!

[Tin Can]

Like

I am now wondering

[Mark Sampson]

How do you plan to keep your enlarging paper in place? For many years on the job I used a Kodak Beacon Precision enlarger- a massive horizontal beast with a 40x40" vacuum easel. That certainly held the paper in the right position, but might be overkill for you. Although it would not be too difficult to build your own, as long as you could vent the exhaust outdoors.

[John Layton]

I already have a working easel setup which I use for the 5x7/8x10 vertical enlarger (the base of which I'll use for the 11x14 also). Here I'll repost my earlier "big print setup" photo (here set up for 5x7) - which shows, in the background - the easel (a Melamine panel with black painted, closely rabbeted (for effective holding) wood strips) which hold the (vertical) paper plenty flat for edge to edge sharpness. This easel is register mounted to the wall, so I can do test strips before removing it from the wall, unclipping the leading edge hold down so it can receive paper, and placing it against my paper roller, (visible in the foreground), after which it mounts back to the wall for an exposure:

[Mark Sampson]

Seems very well thought out, John. Best of luck!

[Mick Fagan]

All of the horizontal darkrooms we had were equipped with vertical metal walls; we used round magnets to hold the paper in place.

Probably around 90% of our work was colour, working in total darkness at first seemed to be impossible, but after a while it wasn't too hard.

[ic-racer]

My below the lens holder for 6" filters was an awesome performer. No image degredation!

[Duolab123]

Looks great. Fun!!!

[John Layton]

A brief update...progress yesterday on the focus control extension...plus its attached wheeled platform - which supports the front standard and relieves stress on the focus extension rack, while also maintaining lens height over track: