Digital v.s. Film Costs in Electron Microscopy

 
By Bill Mollon, Digital Imaging Product Manager, Gatan Inc.

Anyone who has been working in the field of Transmission Electron Microscopy (TEM) will tell you how important the art and discipline of photography is in their research. As we all know the scientific method hopefully will give you the needed data you’ve been hoping for but the presentation of that data can be just as important. Photography is a complex study and every good microscopist has spent his or her own multitude of time carefully composing and producing quality output from their data. For electron microscopists who use TEM, it has been the understanding and knowledge of photography that helps us in making the right film choice, development techniques, chemical selection, darkroom processing, enlarging and printing techniques that take our data and put it in a form that helps tell the story.A lot of work in the “dark” and dealing with nasty chemicals are all part of the game for all of us who have taken this form of microscopy as a career.

Figure 1 First image by Niépce

Digital technology has been creating the most revolutionary advances in photography since the first photograph was taken in 1826 by Joseph Niepce (Fig. 1 “A view from a window”). Photography has now become a technology driven field that is continuously changing and forcing the “old” analog methods out and replacing them with digital counterparts. Aside from the equipment needed, a lot of pressure on most EM labs is based on “costs of service” and consumables no longer being readily available which drives the cost even higher.

This issue of Know How will take a look at what kind of costs occur when using analog film and compare it to the new digital equivalent that some are being forced to embrace. Hopefully you will find the information beneficial to either substantiate why you may want to take the “digital plunge” and shut down that darkroom, or understand why you might be getting the gentle push to accept it as the new method of presenting and sharing your data.

Costs from Film to Print

Let’s take a look at the workflow that you go through to product the final hardcopy print of your prized micrograph. This will help us breakout the costs of each step so that we can compare it later.

All of these steps of course require alot of time and chemistry to perform the magic of transferring that image seen in the TEM to a piece of photographic paper.

Now that we know the workflow steps let’s look at the material needed for those steps and their inherent cost. For the sake of comparison we will make a few assumptions for our example. Since everyone has their own “schedule” of how many samples they look at and how fast they can do it I will define our typical scenario as having to process 20 cases in one week which will require at least 30 micrographs for each case to be taken on the TEM. We will also assume that at least 2 hardcopy prints will be needed, one for the lab and one for the investigator.

Material Costs

Here is a list of the individual components used to obtain the image and producing the final print. There are a couple of different methods of creating the prints so for our example we will be using an automatic processor that takes the exposed paper and delivers a dried print. Costs for conventional “tray processing” , which takes much longer, are also shown so that you can use them in your own analysis. We will take this information and apply it to a formula to derive the overall cost. Prices shown are typical but may vary depending on your geographic location.

		TEM plate film (4489 or SO-163) $128 / 100 sheets
		Chemicals for processing
		•	Developer $ 12/gal (180 neg.)
		•	Fixer $ 12/gal (480 neg.)
		Chemicals for printing (estimating capacity = 1 week)
		•	Processor activator $15/qt 120sheets/qt/hr
		•	Processor stabilizer $12/qt 120sheets/qt/hr
		•	Paper developer $10 / gal 200sheets/gal
		•	Paper fixer $ 12/gal 200sheets/gal
		•	Paper stock $64/100 sheets, 8x10”
		Storage materials for film/prints
		•	$0.40 / sheet holder
		Overhead costs (labor/hr)
		(# of Cases x # of films) x film cost x print cost x labor time

Using our example schedule of 20 cases in one week that need to be screened, 30 images for each and 2 working prints we can come up with a final cost using the information listed above:

As you can already surmise the total of $4249 has a heavy dependence factor on what you assign as the “labor” rate. For our example we are using a somewhat conservative EM Lab labor rate of $50/hour. Again, you can substitute your own values into the analysis. The last step in the workflow, annotation, is also left out of the cost example. There are a lot of variables in how it is done and the materials used for affixing labels. Keeping in mind that this total amount in our example is only based on 1 week worth of work you can imagine what the yearly cost must be for an average EM lab which is very productive. This type of analysis helps you to define and illustrate how cost of service is determined. The equipment used in these steps has been left out since it can vary greatly depending on the size of the EM Facility.

Now that we have a handle on what it costs to make analog images, let’s turn our attention to what it would take if we had a digital camera system on the TEM. We will follow the same basic workflow and schedule in our example.

Costs from Digital to Print

In our digital workflow there are a few steps that will obviously change. Mostly the change is in those steps involving the “wet” chemistry to process the analog film and prints via a photographic darkroom. Producing the final print now becomes more defined by the type of equipment you have for a printer and its consumables. For our example we will be using a “photo” capable ink-jet printer that produces “dark-room” quality prints. Again, equipment used will have a big affect on other factors such as image resolution of the final print and storage latency of the image.

Material Costs

Here is the list of the individual components used to handle the digital image and produce a print.

		Digital image file $0
		Chemicals for processing $0
		Chemicals for printing (estimating capacity = 1 week)
		•	Ink cartridge(s) for inkjet printer $0.35/sheet ($25/cartridge/70sheets)
		•	Paper stock $30/100 sheets 8x10”
		Storage materials for film/prints
		•	$0.40 / sheet (optional step if printed)
		Overhead costs (labor/hr)
		(# of Cases x # of films) x film cost x print cost x labor time

Using our example schedule of 20 cases in one week that need to be screened, 30 images for each and 2 working prints we can come up with a final cost using the information listed above:

Results

Wow! That’s a significant difference to produce a digital print as compared to one produced from a sheet of EM film. Going digital does reduce the amount of steps needed to produce the print and can actually save the lab a considerable amount of labor time that was spent in the darkroom processing all those negatives and prints. In general terms we can say that digital costs are approximately at least half of those seen with conventional film. It is no wonder that some institutions are seriously looking at EM facility darkrooms as a source of reducing their operating costs. The other cost they see is the physical space needed to support a “wet” chemical based darkroom. I have seen many EM labs fall to the curse of “reduction in space required” and the 1st thing that goes is usually the darkroom. Probably one cost that use to go un-noticed but is now the subject of great concern is the disposal of the toxic chemicals used in a typical darkroom. Removal is quite expensive and another major reason for the darkroom demise.

This example helps to give us a better understanding of the costs that we probably have taken for granted for many years. As I already mentioned there are other factors such as capital equipment used in the process (enlargers, processors, tanks, nitrogen burst, cameras, driers, etc..) that should be factored in if you want a complete cost analysis but I think our example here illustrates the fundamentals that are affected directly.
The other cost based factors to consider are those controlled by the old marketing adage of “supply and demand”. Even though there is a strong demand we are seeing technology decisions being made by our suppliers of these analog components (chemicals, paper, film, processors) reducing their supply. This drives cost up considerably. Kodak has already announced discontinuing manufacturing of black and white paper which is a prime resource in the EM photo lab. For obvious reasons, the conventional photography market is going the way of all digital and this will have a direct affect on Electron Microscopy labs.

At Gatan we are working on technology that will help you make the transition from film to digital via cameras for your TEM but also on methodology and support that will be needed to replace for example, all those waving hands and arms in the darkroom during your “dodge and burn” session. Software will need to take on the burden of reproducing the darkroom magic to get that perfect print. In the next issue of Know How we will take a look at what I call the “Digital Darkroom” which will show you how you can obtain the same affects but instead using your PC and Digital Micrograph.

Hopefully you will find this article will help you in supporting your transition from the old familiar darkroom to the modern one today in the digital world (Figure 2). Go Digital!

Figure 2 Old darkroom (top), New darkroom (bottom)

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