New designs of corrected dallkirkhamtype telescopes 2005. Takahashi mewlon 180c f12 dallkirkham reflector first. The design was first presented around 1930 and was the subject of correspondence between oregon amateur allan kirkham and albert g. Planewave 17 cdk17 corrected dallkirkham carbon fiber truss telescope fused silica mirror upgrade available. Optics and telescopes new jersey institute of technology. Optical books present us, for every type of telescope, design principles and theoretical performances, which implicitly suppose that this alignment is perfectly realized.
An optical telescope is an instrument that gathers and focuses light, mainly from the visibleir part of the electromagnetic spectrum, to create a magnified image for. I sell only what i use and endorse, call me and let me set you up with optics that suit your needs. Get the best prices on the ag optical idk line of telescopes from opt. Often you read about dall kirkham telescopes not always accurate and correct statements. My optics the alias of the supported services and the products built and developed by ivan krastev, with the purpose of educating the general public and membership on matters pertaining to astronomy and amateur telescope making. New designs of corrected dallkirkhamtype telescopes. Special order item please read terms page before placing order. Takahashi dall kirkham telescopes offer stunning planetary views while coming in a large aperture, but compact instrument.
The mewlon300crs is the largest in the corrected dallkirkhams made by takahashi. The optics, mechanical design, atmospheric conditions all of that has to line up. The modified dallkirkham telescope utilizes an elliptical primary and spherical secondary. Optical books present us, for every type of telescope, design principles and theoretical performances, which implicitly suppose that. Diffractionlimited field size in the dallkirkham twomirror telescope in terms of the field in a paraboloid f, dk secondary magnification m, and dk primary mirror focal ratio f 1.
These dall kirkham telescopes offer an optical quality unmatched by most modern scopes. Accordingly, the dall kirkham telescope would be the ultimate telescope, the photo machine for astrophotography with the best picture quality, the highest available field and the best star images. Optical layout of a corrected dallkirkham telescope. Parallax instruments dallkirkham cassegrain ota telescope 10 f20 w7x50 finder, tube rings, conical mirror pi250dk.
The main drawback to the dall kirkham design is that the coma is even stronger than in a classical cassegrain, limiting the useful field of view. It is an affordable, high performance solution for astrophotography and visual use, with a large, flat focal surface that is perfect for modern, high resolution, ccd cameras. Ritchey chretien and dall kirkham telescopes from 6inch to. The optical design of the telescope bears explanation. Due to the corona virus our store is closed to the public until further notice. Nov 18, 2018 the optics, mechanical design, atmospheric conditions all of that has to line up. Today i bought a nos mirror kit originally sold by edscorp edmund scientific co. Dallkirkham vs classical cassegrain posted in reflectors. Oouk optimized dall kirkham telescope 250mm best brands. An excellent telescope for both deepsky and lunarplanetary observing. Good images need good optics, all fitted in reliable, stable and precise engineering. The main drawback to the dallkirkham design is that the coma is even stronger than in a classical cassegrain, limiting the useful field of view.
Tsoptics 6 ritcheychretien pro rc telescope 15470 mm ota. Chapter 18 handbook of optics photonics research group. Can anyone explain the difference in optical performance between these two designs. Corrected, optimized, modified, opt has all the dk. Media astro books dorling kindersley the astronomy book. If youre looking for other sporting optics or weapons scopes, please visit our partner site anacortes outdoor.
The ritcheychretien optical design is a specialized cassegrain telescope designed to eliminate coma, thus providing a relatively large field of view as compared to a more conventional configuration. Oouk optimized dall kirkham telescope 250mm the oouk optimized dall kirkham telescope is a solid 250mm aperture offering of the utmost quality, operating at f6. To assist cool down of the telescope, each model is fitted with three fans. Corrected, optimized, modified, opt has all the dk designs you need. The telescope bag a complete and heavy duty, quick on and off, zippered cover air turbulence lower cover keeps warm body air away from light path 8 dall kirkham. The mewlon 180 is a japanesemade portable premium quality cassegrain that provides sharp contrasty views.
Jul 31, 2019 this planewave 24inch corrected dallkirkham telescope is ready to ship to an excited customer. Show dallkirkham telescopes, takahashi dallkirkham telescopes, and takahashi mewlon. Through proprietary manufacturing methods, takahashi provides concave anellipsoidal primary mirror and a spherical secondary mirror at a reasonable cost. Chapters 5 through 16 apply those principles to various telescope and accessory designs. Dallkirkham telescope combines refractorlike performance in a larger folded optic reflector design. Dks are normally intended for highpower planetary observing where only a small field is used. An rc has a hyperbolic primary and a hyperbolic secondary mirror. The modified dallkirkham telescope utilizes an elliptical primary and spherical secondary mirror as in the conventional dallkirkham configuration, but also includes a lens group usually two or three lens elements ahead of the focal point to improve offaxis image quality. The dallkirkham uses a spherical secondary in combination with an elliptical primary. A cassegrain telescope consists of a paraboloidal primary mirror just like a.
A classical cassegrain telescope has a parabolic primary mirror and a hyperboloidal secondary mirror. The dallkirkham dk is a design variation on the classical cassegrain. Parallax instruments dall kirkham cassegrain ota telescope 10 f20 w7x50 finder, tube rings, conical mirror pi250dk. The paraboloids focal ratio f a corresponding to dallkirkhams angular field size is nearly independent of the secondary magnification m, and increases linearly with 1. In real optical system, aberrations occur when light from one point of an object do not converge into a. Planewave infrared dallkirkham optical tube assembly 17. A 50% deposit is required for ordering this product. It costs quite a bit more to have this extra lens but, if you compare like with like spot diagrams of an odk with a similar model on the market, the difference is noticeable and, its there for every image you take or visual observation you make, you have the best optical performance available in an optimised dall kirkham, anywhere. It costs quite a bit more to have this extra lens but, if you compare like with like spot diagrams of an odk. Ritchey chretien and dall kirkham telescopes from 6inch to 32inch the comafree performance of a true ritchey chretien telescope is the best base for astrophotography. The telescope bag a complete and heavy duty, quick on and off, zippered cover air turbulence lower cover keeps warm body air away from light path 8 dallkirkham. History invented by master optician horace dall in 1928. Many of these questions indicate there is a considerable amount of misunderstanding as to what the various types of cassegrain telescopes are designed to do and what they are capable of doing. Amazing in performance for planets, the moon, globular clusters, galaxies, virtually anything in the sky.
Collimation is the adustment of the alignement of each optical element of a telescope with regard to the others. As with all the odk models, the odk10 is fitted as standard with an acu3s, 3 focuser to enable a strong focusing platform for. This planewave 24inch corrected dallkirkham telescope is ready to ship to an excited customer. The corrected dallkirkham cdk the cassegrain reflector is a twomirror telescope design invented by laurent cassegrain in 1672. F 9 ritcheychretien telescope with twolens corrector. Ideal optics gaussian optics produces an exact pointtopoint conjugated correspondence between the source and its image. Why do most professionals choose the ritcheychretien design. So are you saying that any 10 f6 newt with premium optics will automatically be better than an ap 10 mak, tec 10 mak f20, and 10 royce dall kirkham. Telescope comes with either carbon fiber or aluminum tube.
Page 1 of 4 building a 4 f15 dallkirkham cassegrain posted in atm, optics and diy forum. Ease of construction, portability, insensitivity to alignment and cheap. Telescope functions astronomical telescopes make objects from space appear as bright, contrasty or sharp and large as possible. To assist cool down of the telescope, each model is fitted with three fans, all positioned behind the primary mirror. Dall kirkham telescopes, or dks, are a type of cassegrain reflector with. Browse an extensive selection of astronomy equipment at telescopes. As with all the odk models, the odk10 is fitted as standard with an acu3s, 3 focuser to enable a strong focusing platform for a wide range of cameras. Building a 4 f15 dallkirkham cassegrain atm, optics. A reflecting telescope also called a reflector is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. I get a lot of queries regarding the purchase of cassegrain telescope optics of some form or another. Dallkirkham telescope article about dallkirkham telescope. These dallkirkham telescopes offer an optical quality unmatched by most modern scopes. On smaller telescopes, and camera lenses, the secondary is often mounted on an optically flat, optically clear glass plate that closes the telescope tube.
Telescope optics is a compendium of optical information, geared to the intermediate to advanced amateur. With the optional reducer flattener, the fratio can be reduced to f9. The dall kirkham has a elliptic primary mirror and a spherical secondary mirror. Image quality is limited by telescope optical quality, actually, by telescope optical aberrations. Optics and telescopes phys 320 lecture 6 wenda cao njit physics department. Takahashi mewlon300crs dallkirkham ota telescope, tlk3502. Building a 4 f15 dallkirkham cassegrain atm, optics and. Parallax instruments 10 inch telescope dallkirkham f20. Browse an extensive selection of astronomy equipment at. Home telescopes dallkirkham orion optics uk odk orion optics uk dallkirkham dk 2501700 odk10 ota.
The mewlon series from takahashi features dallkirkham cassegrain telescopes for visual observation. Ingalls eventually published an article that mentioned the design, calling it the dall kirkham, and the name stuck. Ingalls eventually published an article that mentioned the design, calling it the dallkirkham, and the name stuck. The dall kirkham uses a spherical secondary in combination with an elliptical primary. Proceedings paper new designs of corrected dallkirkhamtype telescopes. The takahashi mewlon 210 at prime focus provides a focal length of 2415mm, focal ratio of f11. The hubble corrected dallkirkham cdk optical configuration is a revolutionary optical design. This 180 mm aperture telescope is an f12, 2160 mm instrument. I solved them by replacing my sct with a 14 planetary dall kirkham telescope. The hubble corrected dall kirkham cdk optical configuration is a revolutionary optical design. The modified dallkirkham telescope utilizes an elliptical primary and spherical secondary mirror as in the conventional dallkirkham configuration, but also. Show dallkirkham telescopes, takahashi dallkirkham telescopes, and takahashi mewlon dallkirkham telescopes. Also, aberrations in popular reflecting, refracting and catadioptric telescope objectives, telescope eyepiece and human eye. It is intended to give a complete treatment of the subject, addressing professionals in research and industry as well as students of astronomy and amateur astronomers.
It utilizes a space age carbon fiber sandwich sort of design for the actual optical tube. An interesting twomirror variant is one with the secondary left spherical. Rkblog showcasing my planetary dall kirkham telescope. The imaging dall kirkham idk series is a premium line of f6. Cdk stands for corrected dallkirkham corrected because a dallkirkham design by. The outstanding performance of the idk series is made possible through the convergence of modern design, careful selection of materials quartz optics. The dallkirkham is another cassegrain corrected for spherical aberration. The vision the companys focus has remained on hedricks vision to create highend. Takahashi cassegrain telescope mewlon 300 crs corrected ota, tlk3502.
The reflecting telescope was invented in the 17th century, by isaac newton, as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. If youre looking for other sporting optics or weapons scopes, please visit our partner site. Takahashi dallkirkham telescopes offer stunning planetary views while coming in a large aperture, but compact instrument. We are your source for astronomy telescopes, eyepieces, astroimaging cameras, and more. My understanding is that the dk is simpler mirrors to produce which yields consistent quality, but as a consequence of that you get more coma off axis, but excellent on axis performance and easier collimation. Mewlon180c dallkirkham cassegrain telescope with dovetail plate. Exact focusing across the odk range is achieved with the acu3s 3crayford focuser featuring a 10. Dallkirkham telescopes expert service unbeatable prices. We are now able to offer this amazing telescope again. The op asked about a specific scope, which was the royce dk. The attraction of the dall kirkham format is the relative ease of fabrication to a very high accuracy by simple null tests of the concave prolateellipsoid primary by specific separation of light source and knifeedge, and of the convex secondary by interferencematching with a previously nulltested concave spherical master.