Tuesday, June 29, 2010

Chladni Day - June 29

Chladni Day is observed on June 29 in Massachusetts, Maine and Puerto Rico, and he is possibly the most important scientist you probably have never heard of. Chladni applet for fun here.

More on Chladni at this link, much more.

Monday, June 28, 2010

90 Second Reagent Formula Used Below

Here is one reagent formula that I got to work with TMY and Efke. As mentioned before, it is like Quaill's recipe, and with the substitution of lye it is like 55 reagent.

I mix 4 ml HC-110, 15ml soapy ammonia which is ammonium hydroxide 5% in water,  and 3 ml Ilford Rapid Fixer concentrate together. The HC-110 is viscous, so I add that in first, then ammonia, then the fixer.  To that I mix in a gram or so of dry sodium sulfite. This is supposed to prevent sludge from becoming too extensive. Total development time = 2 minutes at 70F.  This is more than enough to process one sheet of 4X5 film. Measure the pH and it should be nearly 10.

Afterward I use a standard hypo clearing agent such as more sodium sulfite mixed according to T55 instructions. You only need a little in water, and you can get by with none at all if you wash the negative thoroughly.

The soapy ammonia wets faster and acts like a photo-flo agent, which you definitely need if you are in the field and want the negative to dry fast without streaks.  Another way I have done this is to also substitute the ammonia with 5 grams of sodium hydroxide, but if I do, I mix it in a stainless bowl as it gets hot.  The final pH should be 9.4. Sodium hydroxide can be hazardous. Here are typical pH strips, which are needed to properly tune the reagent.

I do not recommend that you mix these chemicals unless you have adequate training, wear a face shield and gloves, and have proper equipment. Absolutely do not get any chemicals on your hands or in your eyes. Caustic materials such as sodium hydroxide, lithium hydroxide and ammonium hydroxide are common in many detergent and even food processing formulas, but usually in very dilute, weak concentrations. Here I am using more concentrated forms.

This is not our final formula as there is considerable change in the rate of development when used with a DTR process, but it will produce a negative in a hurry.  There is a long experiment planned that would zero in on the right time, mix and receiver sheet that has been discussed at length in this blog. Also the above formula may be apparent to anyone who has read the earlier posts.

Friday, June 25, 2010

I think these are fairly good for 90 seconds

Despite obvious defects, here is super concentrated Reagent 3, which is rather like the formula as 55, but with the substitution of HC-110 for the developer, and with ammonia as the buffer and not sodium hydroxide or lithium hydroxide. No water added.

A total of only about 2 ounces, just poured in, and the Efke 25 negatives were exposed to light 90 seconds after pouring in the concentrate.  The top image is a DTR attempt using an absorbent sponge. Where the concentrate did penetrate, development was nearly complete, which means only a thin film of reagent like this is needed. Well, we knew that, right?

The bottom image is a partially submerged concentrate with no sponge, used as a control. The slope of the Paterson is responsible for the gradient from left to right, and the white areas on both are the consequence of exposing the negatives to room light then watching, and timing, the change to black with the remaining reagent. Time to black was about 30 seconds.

This is a very rapid reagent, and useful for our system. Click on the images to see details. Note the dendritic shapes around the sponge, which are a consequence of wetting action, as well as the mottled action, also characteristic of a kitchen sponge.  Also note there are some good spots.

I see no gross solarization on the can, even though after 90 seconds there was reagent on it in bright room light.  For that reason, I conclude that we have met the 2 minute requirement with room to spare, even with minimal amounts of reagent.  You cannot see what I am reporting without clicking on the images, and I can see how few anonymous visitors actually do click on the images, so please be one of them.

This is vacation time for many and I will leave you to the beach, or the mountains, for a couple of weeks while I focus on Soundwave Research and AMBIT Corp.

Back soon - enjoy Summer, and the long golden hours.

This is the 121st post on this blog. They sure do add up.

Sunday, June 20, 2010

Potatoheart - Tobias Feltus




Fellow Speed Graphic aficionado Tobias Feltus walks us through the iterative process of making images assisted by instant photographic materials, in this case FP-100.  The seemingly quaint Speed Graphic is an essential tool of many analog photographers, and it is quite fortunate for us that Graflex manufactured them by the millions, as we are assured an adequate supply out to at least 2100.  These 60 and 70 year old boxes may need a little bit of fixing up from time to time, but should last indefinitely.  Here is a most realistic and satisfying presentation of artistic use of such a camera, and the overall process of making Potatoheart.

Saturday, June 19, 2010

Friday, June 18, 2010

Everything went wrong, but...

Admittedly a horrible shot of the building across the street, apparently I metered it wrong and overexposed it by a couple of stops, then the Reagant #3 is obviously uneven, and careless handling of the fragile Efke 25 (and it has been sitting in the Riteway since April) resulted in numerous scratches. The photographer failed to focus or compose his Speed Graphic, and used the Xenotar 150 f 2.8, which was fun but not terribly sharp.  Other artifacts include dirt, mud and clods of who-knows-what.  A larger file (200 MB) was scanned in and there isn't much grain, and there is little to no clumping.

Anyway Efke 25 4X5 sheet film, here shown processed in a couple of minutes.  By that I mean processed with a monobath/reagent that works fast, and no presoak, nothing much except a final wash in sodium sulfite to get the hypo out, just like we do with 55, and a splash of Poland Springs bottled water.  I used the Paterson Orbital tank and a very small amount of #3, but this can all be incorporated into a sleeve or holder that could be taken to a location, shot, and processed on the spot.  Click to enlarge it. Click it again if you have to. Look under the tree.

Thursday, June 17, 2010

Still Wanted: Paterson Orbital, with the Motor

I did get one of these, and have just observed an apparent speed increase of the Efke 25 in Reagent 3 using it. That's OK but I would really like to get another one, and the motor base. Or, just a motor base. Maybe I could make a motor base.  Will trade actual money for this item.

Tuesday, June 15, 2010

Park Street Ice Cream

Wish I could say I'm taking time off for ice cream this time of year, when Summer is about to begin, and the warm days and nights make us completely forget the long freezing Winter. It's hard to imagine it.

The Paterson Orbital processor arrived today in great shape, ready to hasten the selection of materials, time and reagents, as well as film choices for new field processable 4x5 black and white negatives.  Having a fast, daylight tank that doesn't use gallons of chemicals is a relief.

It's too bad Paterson stopped producing this product. On the embossed surface, it is marked "patent applied for" but I haven't spotted it yet online. Perhaps Paterson decided it wasn't worth it, or maybe the claims were so narrow that it hardly mattered.  One has to go on ebay and buy from someone in England to get one, and the postage is very expensive.

Image: Park Street Ice Cream, Natick MA, on a Summer evening. Click to enlarge.

Sunday, June 6, 2010

Reagent III Clearing Detail


You might remember far enough back when Monobath III was first used, and there was a concern about chemical fog, but it was incomplete hypo clearing.

It turns out that negative cleared with sodium sulfite.  Forgot to mention this detail, which is going to be important, IF I ever get a Paterson Orbital tank in here.

Friday, June 4, 2010

Nubis


I don't believe I ever posted the Nubis in color before. It once existed on flikkr as a sepia image.

Dr Koger on Comment Spam















Apparently an unfortunate fact of life, people trying to sell anything from hair color to Bermuda cruises. If you find your comment missing in action, it's because it looked like spam to the comment spam filter. The comment spam filter catches most html comments, and html links are turned off to discourage comments with lots of html in them.

Actually Jim Koger does not comment on comment spam at all.  Here he is, some years ago, inventing the short-pulse, zero-ringdown ultrasound transducer that made high quality Intravascular Ultrasound (IVUS) possible. Today it is a $600M business. But at that time, it was thought to be only a $10M business.  "Who needs it?" they asked.

Who indeed! Docs putting in stents, that's who, and a lot of them.  Drug coated stent FDA approvals require the use of IVUS. Yes, that means that the $4B business of drug coated stents would be much smaller, maybe nonexistent today, if not for the measurement and imaging capability of IVUS to produce a high quality grey scale image of the cross section of a human artery.More on that here.  Just good to keep in mind - images enable things to happen, images are important, seeing precedes doing, and what you do can depend entirely on how you see it, or image it.

To image the waves of the transducer, the part that acts like the lens of the camera, Jim used up crates of 667, seen in the background to optically, permanently capture fleeting traces on the screen.  None have ever been lost, overwritten, corrupted or virus-infected.

Today we wasted hours trying to save a screen image on our brand new Agilent portable spectrum analyzer but find it cannot be done except in a crappy jpeg format that is unprintable in any normal printer. I nearly broke out the scope camera and might do so if Agilent can't tell us what a .TNG file is. 

TMY 6X4.5cm negative. Click on it for a real view.