High contrast high resolution
Posted: Wed Feb 17, 2010 4:46 am
Hi! This is my first time posting here. I'm after some developing advice. Let me first explain my project: I'm making microfluidic chips - these are little plastic chips with channels approximately 100 microns wide molded into them. To make the chips pour liquid plastic over a mold which has the channels standing up in relief. To make the mold we use photolithography - a UV curing epoxy resin is coated onto a substrate, then the resin is exposed to UV light through a contact mask which has the required channel pattern on it. When developed the epoxy is left only where it was exposed to UV. So usually the mask is made from a high quality quartz plate onto which a chromium film has been placed and the pattern etched by e-beam lithography. This produces stunnign results but there is a considerable lead time on the masks and they are not suprisingly expensive. So I've been experimenting with using 35mm film for the masks. I make my design on a computer, print it off on an A0 printer and then photograph the print with my 35mm SLR. Develop it and then use the negative itself as the contact mask for the resin. Obviously the image needs to be pure black and white as best as possible with no grey shades. The edges have to be as super sharp as possible, I want to be able to have lines down to 50 microns wide on the negative itself.
First off I used Ilford Pan F+ but it was too grainy and not contrasty enough. Then I used this Bluefire Police film with their special "micro" developer. I got excellent results (see attched) However I ordered some more BF Police before xmas and it still hasn't arrived and they are noe replying to any e-mails I'm suspecting they may have gone under (anyone know?) Anyhow I'm trying alternatives - I bought Rollei ATP 1.1, Efke 25 and Fuji Neopan 100 Acros and for developers I have Rollei ATP DC, RLC (it came in the kit!), Spur 2525, Kodak HC110 and Xtol as well as some of the bluefire micro dev and Ilford Ilfosol3 I had left over.
I've tried the Rollei ATP in both Rollei developers, the edge sharpness is just as good as the Bluefire but I cannot stop the film fogging meaning my "clear" areas are far from clear. To summarise, what I need is black areas as black as black can be, white areas as clear as water, nothing in between and super sharp grain free edges ( not too much to ask ) oh and it must be 35mm - the whole point of this is that it's supposed to be quick and cheap, if I have to go an buy a larger format camera I've kind of defeated the object (plus my chip systems are now designed around a 35mm chip to match the negative. Any thoughts/advice on how to achieve this would be very welcome. BTW I'm taking the pictures with a Pentax MZ30 with 35-80mm lens (generally kept at the 80mm end - I need straight lines!) usually about f/5.6 - f/8, generally I took the Bluefire at ISO80 as per their recommendations but I found 2 to 4 stops overexposure gave the best contrast and grain.
Anyway, sorry that's a pretty long winded question, but I've pushed my own meagre photography experience to the limit with this, I had something that worked, and now it's gone I need a replacement because I've based a lot of my project on this approach! Thank in advance http://www.flickr.com/photos/64866105@N ... 452403264/
First off I used Ilford Pan F+ but it was too grainy and not contrasty enough. Then I used this Bluefire Police film with their special "micro" developer. I got excellent results (see attched) However I ordered some more BF Police before xmas and it still hasn't arrived and they are noe replying to any e-mails I'm suspecting they may have gone under (anyone know?) Anyhow I'm trying alternatives - I bought Rollei ATP 1.1, Efke 25 and Fuji Neopan 100 Acros and for developers I have Rollei ATP DC, RLC (it came in the kit!), Spur 2525, Kodak HC110 and Xtol as well as some of the bluefire micro dev and Ilford Ilfosol3 I had left over.
I've tried the Rollei ATP in both Rollei developers, the edge sharpness is just as good as the Bluefire but I cannot stop the film fogging meaning my "clear" areas are far from clear. To summarise, what I need is black areas as black as black can be, white areas as clear as water, nothing in between and super sharp grain free edges ( not too much to ask ) oh and it must be 35mm - the whole point of this is that it's supposed to be quick and cheap, if I have to go an buy a larger format camera I've kind of defeated the object (plus my chip systems are now designed around a 35mm chip to match the negative. Any thoughts/advice on how to achieve this would be very welcome. BTW I'm taking the pictures with a Pentax MZ30 with 35-80mm lens (generally kept at the 80mm end - I need straight lines!) usually about f/5.6 - f/8, generally I took the Bluefire at ISO80 as per their recommendations but I found 2 to 4 stops overexposure gave the best contrast and grain.
Anyway, sorry that's a pretty long winded question, but I've pushed my own meagre photography experience to the limit with this, I had something that worked, and now it's gone I need a replacement because I've based a lot of my project on this approach! Thank in advance http://www.flickr.com/photos/64866105@N ... 452403264/