Dark Field Technology and our Dark Field Offer

Since 06.05.2010 when we sold our first darkfield microscope (at that time an OPTIKA B353DK) we received from our customers a number of questions about dark field technology. On this page you can find answers to the most frequently asked questions concerning the selection of the technical dark field equipment. You will also find information about our offer, sample captures taken by our offered equipment, video tutorials and some customer opinions.

Questions and Answers about the Dark Field Equipment

What is the advantage of buying a LED Dark Field Microscope?

LED technology has revolutionized many areas of technology - including microscopy. Most manufacturers equip their microscopes now from halogen to LED. We recognize this trend very significantly not only in the dark field but in all types of microscopes, which we distribute. The LED lighting has many advantages - some of which are as follows.

• Lifetime - The longevity of the LED (50,000 hours according to manufacturer OPTIKA) eliminates the permanent replacement of lighting halogen lamps.
• Color of the light source - The use of white LEDs eliminates the "Yellow tinge", which is visible in the halogen lamps.
• Silent and compact - So far, the halogen lamps were usually in an external device and the light has been brought with light guides to the condenser. The halogen lamp had to be cooled with a fan, which is loud. Using LED lighting you do not need a second external device and operate compact and noiseless.
• Low power consumption - While consumption of halogen lamps is about 100-150 Watts, LED consumes depending on the model up to 7 Watts.

What I need to know to be able to use a dark field microscope?

If you have never worked before with a dark field microscope, you will need definitely to understand the process of condenser centering and learn to work with the immersion oil. During on-site installations we will train you, if you order online we provide you with a printed manual (in addition to the manufacturer's instructions).

What lenses and magnifications I need in the dark field?

That depends on your application. If you carry out investigations according to Dr. Enderlein's method, you need the lenses 10x, 40x and 100x (with total magnification 100x, 400x and 1000x). The 10X objective is used for the centering of the condenser. The actual viewing is done with the 40x and 100X lenses.

Can I achieve magnifications of 2000x or more in the dark field?

Of course you can use stronger eyepieces and thus reach higher magnifications than 1000x, but you should know that there are physical limits to the magnification and such ones would be "empty magnifications", that is, you no longer gain more optical information (a good comparison is the optical and digital zoom of a photo camera). You can trust that the manufacturers of microscopes invested much time and money in the development and if technically possible and useful, they would have already have offered such magnifications.

What is the difference between Achromatic and Planachromatic Objectives ?

Achromatic microscope objectives have in comparison to other types of objectives the simplest optical structure and the lowest price level. One drawback is that they have a field curvature and therefore find application mainly in simpler laboratory microscopes as well as for routine tasks when the remaining field curvature does not interfere.
Planapochromatic microscope objectives have achromatic or apochromatic correction, where in particular, the curvature of field for an intermediate image of medium size (normal field) is corrected. Modern plan objectives have a flattened image field of 20 to about 25 mm in diameter. They are used in laboratory and routine microscopes and in the micro photography.

Some dealers even build darkfield microscopes - You too?

No - alone for the development and production of a single component of the microscope as its objective needs manufacturers systems with clean rooms and staff of several dozen people. We sell microscopes and microscope cameras from renowned manufacturers under the original manufacturer name. We sure combine microscopes, adapters and cameras from different manufacturers to achieve the best result, but never engage technically into the product - that is the task of the manufacturer who specializes in this task. It may be that there are traders who buy microscopes of a manufacturer, then modify them technically and then sell them as their own product under a different name (often the dealer's name or a fictitious name) - in this case, you have no guarantee from a renowned manufacturer but depend on the dealer because he is the only who "knows" this product.

Have microscope cameras with higher megapixel number, the better picture quality?

No - depending on the model, a camera with less megapixels and a high-quality sensor, can have a better picture than one with more megapixels but lower quality sensor. The image quality of the camera (e.g. making visible of very fine structures) depends on various technical parameters such as of the dynamic range of the sensor. You should watch the image quality live or see video recordings to judge the quality by yourself - the quality differences are large and just the number of pixels is not enough for the decision.

Which number of pixels should I choose for my microscope camera?

Generally one can say that the number of pixels is to be adjusted to your display size. At a 19" screen (native resolution of 1280x1024 pixels) a 1.3 megapixel camera is also sufficient. In our demonstration room we use as a 27 "screen in full HD resolution - that is 1920x1080 pixels, so 2.07 megapixels. Should we use there a 10 megapixel camera, the monitor can still show no more than 2.07 megapixels. Moreover it comes with the USB transfer in the case of cameras with high megapixel number, all this data volume is passed through the USB channel making the frame rate smaller. So you can reach for example, with Optikam B9 (10 megapixel camera) a maximum of 3 frames/second while usieng a camera with 3 megapixels provides more than twice that speed. For the purposes of darkfield you need a fast image, since you watch also moving objects!

Can i use my SLR with a dark-field microscope?

Yes - although this is more the exception, we have customers who do not need a live view on the screen and prefer to work with their own camera. For the connection you need a so-called T/2 connecting ring from the manufacturer of your SLR (available at photo shops) and the "matching" adapter from microscope manufacturers, which we deliver. The "matching" adapter because depending on the modelof your SLR, usually you have a full-frame or APS-C sensor inside. These sensor types have different sizes and therefore need a different adapter to cut down the microscope image to the "right" size. When choosing a wrong adapter you will see either only a small part of the image or will have black areas at the outer borders. We can assist you with the configuration of such setups.

Are special solutions possible in the camera software?

Yes - the software of our cameras can more than "just" the live image and save photos. Some camera software for example, shots every prefined time a photo and thus document the decay. Other software modules can make comparisons or counting. Just let us know if you need something special!

What are the differences between HDMI and USB cameras?

Please note here that our HDMI cameras can also be used as USB cameras, since next to the HDMI they have also have a USB output - the picture quality is, however, in HDMI mode higher. In general, the trend of our customers goes toward HDMI cameras.

• Setup - HDMI cameras have the advantage that they connect directly to any monitor or TV device having a HDMI input - so you do not need a PC and no software setup. Connect the cables, turn on te camera and the picture is here!
• Frames per Second - The signals from the HDMI cameras are not "slowed down" through the USB channel of the PC and therefore reach very high frame rates. Our HDMI cameras achieve in Full HD resolution 60 fps while USB cameras achieve depending on the model between 7-25 fps.
• Camera Control - With USB cameras you can control all parameters (brightness, contrast, etc.) through the software on the PC. HDMI cameras have an on-screen menu that is displayed on the screen - there you can control all the parameters.
• Image/Video capture - USB cameras capture photos on the PC using their application. With HDMI cameras the photos are recorded on a removable SD card, which is located on the camera. If necessary, they can always be transferred to a PC.

What must be considered when choosing the adapter between the camera and dark field microscope?

In addition to the quality of the lens, one should note if the adapter has a fixed or variable focal length. The former are chaper. With the ones with variable focal length you can focus the image through the eyepieces and then by varying the focal length of the adapter also on the screen and get both images sharp at the same time. This adjustment you make only once. With a fixed focal length you have almost always a variation and you always have to readjust with the fine course, if you change from the eyepieces to the screen, which is annoying. If you work only with the screen image, then the fixed focal length is the better choice as it is more economic.

Our Dark Field Offer

When choosing our suppliers for dark field microscopes we followed the needs of our customers and considered the following factors:

• Brand: By choosing a reputable manufacturer like OPTIKA, a level of quality and the technical and warranty support are guaranteed – contrary to "noname" products.
• Image quality: The B500-TDK is the top model of OPTIKA in the area of biological dark field microscopes. Meanwhile, the satisfaction of our customers has repeatedly confirmed this.
• State of the art: LED technology is integrated within the device - so no halogen lamp replacement and no loud cooling fans for halogen lamp cooling is needed. High quality 100X lens with a built-in iris. Plan-achromate optics for a sharp image over the entire field of view.
• Extensibility : With optional adapters, microscope cameras and SLR cameras can be connected - even microscope cameras from other manufacturers.
• Price-Performance ratio: With the B500-TDK (but also with the recently introduced lighter version B383-DK), we are convinced that we can offer the best price/performance ratio for the requirements of our customers.
• Training and Support: We can assemble the B500-TDK for you on-site, calibrate and train you in the calibration / usage - this service is highly recommended for customers who have never worked with a dark field microscope before.
• Technology upgrades: Should after a few years of the technology state of the art change, we offer to our customers targeted upgrades. We offer e.g. to exchange your older microscope camera model (bought from us) against the latest HDMI cameras - many of our customers already benefit from this.

Customer Reviews

I use since more than two years the Italian Optika B-500TDK darkfield microscope in my doctor's office and I am with workmanship and image quality very satisfied. It is hard to find a difference in quality compared with similar products which are 3 to 4 times more expensive and which are usually propagated in the courses by the speakers.

I am also very impressed by the LED light. With only 4 Watts of power consumption, it shows no heating effect of the sample, and so no noisy cooler disturbs as with the usual 100-Watts halogen lamps."

Dr. Helge Richter, General Practitioner, 1010 Vienna, Austria


My company organizes dark field seminars for all levels with professors from all around the world. In our training center in Vienna on the one hand, the theory basics are teached, on the other hand, the participants should get acquainted with the practical work with the dark field microscope. We use in our trainings the OPTIKA the B-500TDK: excellent image, silent and easy to use. Many of our participants made already the same choice as we did.

Maria Mudro, CEO of „Gesundheitsakademie Wien“,
Otto- Bauer- Gasse 20, 1060 Vienna, Austria


I bought end of 2014 my dark field microscope OPTIKA B383-DK from Sarras eU. When I unpacked my new microscope for the first time, I was impressed with how stable and "scientific" it looked like. The assembly of the microscope was quick and effortless. As a medical scientist (Onkogenetics - pathologist) I have always worked with top microscopes of the most famous manufacturers. I can confirm that working with this dark field microscope is more than sufficient, you don’t need any more to look further for more expensive or larger microscopes.

In my opinion, an advantage of the B383-DK microscope is that this model is both compact and lighter than the B500-TDK, on the other hand, just as "professional" to work in the dark field. It enables easy transportation for home visits as it fits easily into a microscope suitcase. Ideal for the office, but also to take it with you!

Dr. Edwin A. King M.Sc. Ph.D., Biomedical - DFM consultant and therapist, Vienna, Austria

Our pre-sales services

• Free technical support during the choice of the appropriate combination of devices. We do not "only" sell these products but we have thoroughly tested almost every offered combination. Further we have many years of experience and lots of successful setups at several customers in Austria, Germany and Switzerland. You can take advantage of our experience and have a free technical consultation.
• Product Demonstration and Training: By appointment you can test the offered dark field sets in our showroom in Vienna and assess the differences in image quality and ease of use of the software itself. You can also book a crash-course for the technical usage of the microscope and the cameras.

• Free additional documentation: Customers who cannot benefit from our setup service (mostly because of the geographical distance), receive a printed manual (in addition to the manufacturer's instructions) and video instructions (e.g. for the assembly of the microscope) which both help to have a smooth and quick start.

Our after-sales services

• On-site setup Assembly of the microscope, software setup, calibration and technical enrolment. Customers who have already worked with a dark field microscope will normally not need this services. If you have never worked with a dark field microscope before, however we recommend you to book our service. The cost for this service depends on your location.
• Support during warranty cases: Should it ever come to a problem, you just need to notify us - we organize for you with the technical support team of the manufacturer the steps needed. Please note that the warranty period for each unit, guarantee conditions and repair times depend on the guarantee conditions of the respective manufacturer.

Sample captures of the OPTIKA B500-TDK

Video guides

The following links with instructions do not intend to replace the included manufacturer's documentation. They aim to help customers who cannot benefit from our setup service, to achieve a smooth installation and a quick start.

• How to assemble the microscope?
  
• How to apply immersion oil with the 100X oil immersion lens?
• How to attach the microscope camera?