High contrast high resolution

Film Photography & Darkroom discussion

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jameshoyland
Posts: 6
Joined: Wed Feb 17, 2010 3:50 am

High contrast high resolution

Postby jameshoyland » 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 :lol: ) 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/


Lowell Huff
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Re: High contrast high resolution

Postby Lowell Huff » Wed Feb 17, 2010 10:48 am

you need a high contrast, micro film developer. Our MS Micro Developer is my recommendation

jameshoyland
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Joined: Wed Feb 17, 2010 3:50 am

Re: High contrast high resolution

Postby jameshoyland » Wed Feb 17, 2010 3:21 pm

Is that available in Europe? Can you give me any more info on it?

Lowell Huff
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Re: High contrast high resolution

Postby Lowell Huff » Wed Feb 17, 2010 3:30 pm

I can ship it to Europe. You can order it through Digital Truth. Cat # 51 1317,Packaged 4x1gallon case, dilutes 1+7.

jameshoyland
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Joined: Wed Feb 17, 2010 3:50 am

Re: High contrast high resolution

Postby jameshoyland » Thu Feb 18, 2010 2:56 am

I can't seem to find that on digitaltruth at all. Also that seems like a large amount. I'm going to want to test it before I order that much, do you have smaller trial packs?

Digitaltruth
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Re: High contrast high resolution

Postby Digitaltruth » Thu Feb 18, 2010 5:59 am

We can supply all Clayton chemicals worldwide, but some items are not listed in our store so you will need to email us for shipping information. Bear in mind that shipping liquids internationally is usually expensive as the US Postal Service no longer offers surface mail, and the lowest cost option for packages over 4lbs in weight is Priority Mail.
--Jon Mided

Digitaltruth Photo
http://www.digitaltruth.com

jameshoyland
Posts: 6
Joined: Wed Feb 17, 2010 3:50 am

Re: High contrast high resolution

Postby jameshoyland » Thu Feb 18, 2010 2:34 pm

I had realized that shipping large amounts of chemicals accross the atlantic would be expensive. I'm at the stage of experimenting with different approaches so I don't want to buy big batches of anything. Does anyone have any other suggestions.

Lowell Huff
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Re: High contrast high resolution

Postby Lowell Huff » Thu Feb 18, 2010 4:38 pm

JAMES:
You asked for an answer to your issue. I have provided it to you. Now you dismiss me because you ASSUME that the price of our chemistry is too high. Have you given any thought to the fact that you are willing to pay extremely high prices for European manufactured chemistry just because it is on the continent, that do not provide the desired results? Did you even consider that the Euro is 1.70 to 1 and the £ is even higher right now? Do any of the developers you have used dilute 1+7? So your concerns are not well founded in logic or economics.

jameshoyland
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Joined: Wed Feb 17, 2010 3:50 am

Re: High contrast high resolution

Postby jameshoyland » Fri Feb 19, 2010 2:17 am

Lowell, I did not mean to offend you and I wasn't dismissing you. Thank you for your input on my question but I was hoping for a few more informative responses from people on the parameters that control grain size and contrast rather than just a suggestion for a particular product - I was hoping to learn something. And with the greatest of respect you did not actually tell me anything about your product, or point me to any literature on it or reviews - I checked out your website and couldn't find anything detailed. European chemicals may be more a little expensive but my shipping costs are minimal and I can pruchese the small amounts I need to experiment with - plus I don't need to pay import duties within the EU and my employer can reclaim the taxes on European products. (BTW according to xe.com 1 Euro is 1.34 USD right now) . Not sure what your point about dilution was.
As a matter of interest, I got pretty good results with the Efke 25 in the Kodak HC-110.

miha
Posts: 44
Joined: Tue Jan 20, 2009 11:42 am

Re: High contrast high resolution

Postby miha » Fri Feb 19, 2010 7:34 am

James, my understandig is that you need a high contrast document developer. The one that meets this criteria is Rollei RHC high contrast developer. I also read that Efke 25 film pushed two stops and developed in Ilford Microphen developer turns into a balck-and-white negative with almost no mid tomes.

p.s. you can get Rollei and Ilford (or ADOX) cheaper here in EU, with less of an "attitude".

jameshoyland
Posts: 6
Joined: Wed Feb 17, 2010 3:50 am

Re: High contrast high resolution

Postby jameshoyland » Fri Feb 19, 2010 4:01 pm

Thanks for your suggestion Miha, I had wondered about pushing but I understood it tends to increase grain size as well? The efke 25 turned out fairly well in HC110 but still had a fair bit of grain in the white areas. I tried Rollei ATP in their "DC" document-type developer which was also pretty good. The resolution compared well with the Bluefire Police but the contrast was not as hard. I'm going to try and get hold of some Microphen and some RHC next week.

jdefehr
Posts: 1
Joined: Mon Mar 15, 2010 10:55 am

Re: High contrast high resolution

Postby jdefehr » Mon Mar 15, 2010 3:23 pm

James,

It seems to me you want document film, like Kodak Imagelink film, or similar. A tanning developer seems ideally suited to your application, because it produces a relief image by proportional hardening the emulsion. Some films produce more relief than others, as a consequence of the emulsion make up; some use more gelatin than others. To get maximum relief from any film, you should swell it before/during development. A soak in hot water will swell the emulsion, but some films tolerate high temperatures better than others do. Films that swell most, are least tolerant of high temperatures. Modern films are generally well hardened for high temperature processing, and old world films, like Efke/Adox generally are not. A high solution pH also swells emulsion, and a combination of high temp/high pH is typically used.

You don't want a developer designed to produce pictorial contrast with document films, you want a lith developer, for maximum contrast.

http://www.freestylephoto.biz/50022-Ari ... cat_id=305

If you are willing to compound your own developer, I'd be happy to provide a very cheap, simple and effective formula for a lith-type tanning developer.

Good luck!


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