Health product - help for problems in the stomach, blood circulation, respiratory system, musculoscheletal system, immune defence, hormonal system, skin, urogentital organs and more, including hypotyroidism, edema, over-weight, hemorrhoids, allergies airpipe infections, male and female issues, skin diseases, UTI, PMS, rheumatism, circulation problems, depression.
Click here for items to increase sexual libido, excitement, pleasure, erection size, vulvar blood flow and engorgement, female and male secretions and lubrication, orgasmic intensity and for products to enlarge and reshape the male sexual organs and female breasts.
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Scientific products for hobby and professional use - also other hobby items
If you have science as your hobby,
you can find a lot of articles for your speartime activities here for an
affordable prize: Kits and components for hobby electronics, microscope for the
hobby biologist, telescopes for hobby astronomers, binoculars you can use in
field investiqations, and a lot more. Many of the most advanced products are of
professional standard, and can also be used in professional environments. You
can also find other hobby equipment like remote controle models of helicopters,
aircrafts, cars and boats. Further down on this page there is also an article
about telescope design.
The products exhibited on this page are only examples of a huge collections. By clicking on the links, you can learn more about the exhibited products or find a lot of other products of the same type.
EQUIPMENT FOR DETECTION OF RADIATION OR GASSES IN THE AIR
Geiger counters - radiation detectors
A geiger counter can be useful to detect and assess the radiation level in the surroundings. It is also useful to explore the geological composition in an area, to find special rock types and to investigate certain types of human activities.
BINOCULARS AND BINOCULAR CAMERAS
NIGHT VISION SCOPES, BINOCULARS AND CAMERAS
Electronic kits and components - please go here
To find kits for experiments and learning about physics, chemistry, biology, electricity, magnetism and general sience - please click here
GOOD SOURCES OF ALL KIND OF HOBBY PRODUCTS
Two good general hobby stores - In these stores you can find RC models of airplanes, boats, cars, drones, robots, tanks and construction mashines. You can also find a huge inventory of hobby guns. There are also magic kits and magic tricks.
Two good sources pf all kind of technical products, including telescopes, microscopes, cameras, camcorders, binoculars, Computers, cellphones, audio, video, gaming, components, software. - These are big stores where you can find a lot of technical items for hobby and daily use, and many more special products for professional use. Among the products are: all kind of optical devices, rc models, computers. electronic components and experiment kits, home theaters, audio, video, cellphones, gaming, networking equipment, surveillance and security, automtion, office solutions, software, car electronics, tools for hobby and work.
INFORMATION ABOUT TELESCOPES
Generally about optical telescopes
An optical telescope gathers and focuses light mainly from the visible part of the Electromagnetic spectrum (although some work in the infrared and ultraviolet). Thereby also pictures of the objects that the light originates from will be focused. Optical telescopes increase the apparent angular size of distant objects, as well as their apparent brightness. Telescopes work by employing one or more curved optical elements - lenses or mirrors - to gather light or other electromagnetic radiation and bring that light or radiation to a focus where the image can be observed, photographed or studied.
Practical telescopes have at least two main lenses or lens collections. The objective resceives the light and focuses it. The oculular or eyepiece enlarges the image of the object further. The objective will make the image up- to down and right to left. To counteract this effect, many telescopes have a third element between to convert back.
The focusing can be done with convexe lenses, that is lenses that are thickest in the mid. They can also be done by concave mirrors, that is mirrors that bulge inwards at the side that collects the light. A combination of lenses and mirrors can also be used.
It is also possible to use mirrors to let the light go forth and back through the same tube. In this way the telescope can be made a lot shorter. There are three main types of telescopes.
The refracting telescope in which the light goes only through a collection of lenses to be focused after having passed.
- The reflecting telescope which uses only an arrangement of mirrors that eventually reflects the light onto a plane.
- The catadioptric telescope which uses a combination of mirrors and lenses.
Optical telescopes are used for astronomy and in many non-astronomical instruments including theodolites, transits, spotting scopes, monoculars, binoculars, camera lenses, and spyglasses.
A typical refractor has two basic elements, a convex objective lens and an eyepiece lens. The objective in a refracting telescope refracts or bends light at each end using lenses. This refraction causes parallel light rays to converge at a focal point; while those which were not parallel converge upon a focal plane. This can enable a user to view the image of a distant object as if it were brighter, clearer, and/or larger. Refracting telescopes can come in many different configurations to correct for image orientation and types of aberration.
The original design Galileo came up with is commonly called a Galilean telescope. It uses a convex objective lens and a concave eyepiece lens.
The first telescope used the same principles that all telescopes would rely upon. The combination of the two lenses gathered more light than the human eye could collect on its own, focused it, and formed an image. Because the image was formed by the bending of light, or refraction, these telescopes came to be known as refracting telescopes or, simply, refractors.
Galileo’s best telescope magnified objects about 30 times. Because of flaws in its design, such as the shape of the lens, the images were blurry and distorted. But it was good enough for Galileo to explore the sky.
The Keplerian Telescope, invented by Johannes Kepler in 1611, is an improvement on Galileo's design. It uses a convex lens as the eyepiece instead of Galileo's concave one. The advantage of this arrangement is the rays of light emerging from the eyepiece are converging. This allows for a much wider field of view and greater eye relief but the image for the viewer is inverted. Considerably higher magnifications can be reached with this design but to overcome aberrations the simple objective lens needs to have a very high f-ratio (Johannes Hevelius built one with a 45 m (150 ft.) focal length). The design also allows for use of a micrometer at the focal plane (used to determining the angular size and/or distance between objects observed).
The achromatic refracting lens was invented in 1733 by an English barrister named Chester Moore Hall although it was independently invented and patented by John Dollond. The design limits the effects of chromatic and spherical aberration by using an objective made of two pieces of glass (with different dispersion), "crown" and "flint glass". Each side of each piece is ground and polished, and then the two pieces are assembled together. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus in the same plane.