Focal length, usually represented in millimeters mmis the basic description of a photographic lens. The focal length of a lens is determined when the lens is focused at infinity. Lens focal length tells us the angle of view —how much of the scene will be captured—and the magnification —how large individual elements will be. The longer the focal length, the narrower the angle of view and the higher the magnification. The shorter the focal length, the wider the angle of view and the lower the magnification.
There are two types of lenses-prime and zoom. Prime lenses have a fixed focal length and zoom lenses have variable focal lengths. Standard lenses are popular as they are closest to the angle of view we humans see. They tend to use large apertures and allow a lot of light to enter the lens which makes them fast in low light conditions.
Standard lenses are the popular choice for a wide range of photography including portraiture, nature and low light situations where the photographer can not use a flash or is looking to capture the scene with available light.
They allow the photographer to produce close crops on the subject. In the case of portraiture a telephoto allows the photographer to take the photo at a distance that does not intrude upon the subject. These lenses are popular for subjects such as flowers, insects and small products. By clicking Sign Up, you are opting to receive educational and promotional emails from Nikon Inc.
You can update your preferences or unsubscribe any time. Search Articles. Glossary Off On. What is Lens Focal Length Focal length, usually represented in millimeters mmis the basic description of a photographic lens. Standard Lens FX format approx. Telephoto Lens FX format approx. Super Telephoto Lens FX format approx. Did you like this article? More Like This More articles like this. Article Collections. Articles like this, right in your inbox. First Name required. Last Name required.
We understand that many of our products are technical in nature and require support. Rest assured that our team of Telescope and Telescope Accessory experts will be standing by Maksutov-Newtonians offer the added bonus of built in field correction, and so they are a big step up from a fast Newtonian, but they also compare favorably to Schmidt-Newtonians, offering more contrast and sharper images.
Besides the optics, the focuser is one of the most important components of a telescope system, and that is especially true when imaging. The Sky-Watcher 7. The Sky-Watcher Starlux MN comes with a right-angle erect image 9 x 50 finder and bracket as well as a tube ring set with a V-Style Vixen dovetail bar. Skip to the end of the images gallery. Skip to the beginning of the images gallery.
In stock Ships in one day This item is in stock and typically ships in 1 day or less. Tech support Free Lifetime Tech Support.
Non-Commissioned Product Advisors. Fast Shipping, Same or Next Day: You made the commitment to purchase, now you want that new item fast, we get it! At High Point all in stock orders ship within 24 hours, pending internal credit card approval. Read more Unlimited Tech Support Forever: One of the many perks of being a High Point customer is that you get access to our tech support team forever!
We are astronomers at heart and truly enjoy helping fellow amateurs achieve success in the field! Don't worry, we'll take the majority of our products back within 30 days of the purchase date.
What is Focal Length and Which Lens Should I Use?
We want to get you into the observing setup that bests fits your needs. Guaranteed Price Match: Call or email us if you find a better price on a product! Provide a link for our team to confirm the price and within a matter of seconds you'll have a price match providing the re-seller is within the USA and authorized by the manufacturer to sell the product of interest.
We're Your Connection To The Manufacturer: In the event there is a warranty issue with a product purchased from High Point, we will serve as the liaison between you and the Manufacturer. The net result is faster, more attentive service from the Manufacturer and an enhanced customer experience. Ask an Expert. Out of stock. Add to Cart. Warranty Info Close Warranty Manufacturer's warranty period, if known.
Customers should communicate directly with the manufacturer regarding details of their warranty, as warranties have a tendency to change without notice.One of the most important reasons why you buy a lens is down to the focal length.
This lets you know how close you need to be in relation to the subject you are capturing. A longer focal length is necessary for objects further away. A smaller focal length captures more of the scene in front of you.
To understand focal length in four, easy steps, read on. Product links on ExpertPhotography are referral links. If you use one of these and buy something, we make a little bit of money. Need more info? See how it all works here. Knowing what focal length means in relation to your camera is very important when it comes to buying lenses. Lenses are divided into two categories based on whether they can zoom.
Focal Lengths and Your Digital SLR Camera
There are the ones that have a fixed focal length prime lenses. And there are those that have a variable focal length zoom lenses. In general, prime lenses are sharper and often have a wider aperture. These are great for low light conditions.
Zoom lenses allow you to use one lens to cover a range of different photography fields. One lens means less time spent searching for and changing lenses. There are advantages and drawbacks to both types of lenses.
So, having a mixture of them gives you versatility and power. We can use the human eye as an example. Its focal length varies between 17mm and 25mm, depending on who you ask and who you examine. The area that we actively perceive is smaller, similar to a mm lens. The higher the number, the more zoomed your lens will be. This is the case of simple lens designs like Double-Gauss. There are also plenty of complex optical designs that work differently. In many cases, that distance is not equal to the focal length.
These lenses are often considered speciality items. Usually, they are not included as part of a starter kit.No tweaking was needed at all, and there were pin sharp stars all the way out to the edge of the field. It really is like having a mm triplet apochromat in your hands, but for a fraction of the cost" The exciting new Maksutov-Newtonian from Sky-Watcher is just what astrophotographers and serious visual observers have been looking for.
The Maksutov-Newtonian design combines the best features from the Newtonian Reflector and the Maksutov-Cassegrain to create a telescope design that provides truly stunning image quality, providing high-contrast, perfectly flat images, free from false colour. The Maksutov-Newtonian design provides large aperture Apochromatic performance, with exceptional field correction, in a compact, amazingly affordable package.
Stars appear as classic pinpoints across the entire field. Perfectly optimised for modern DSLR cameras. The premium optics are housed in a robust rolled-steel tube for excellent mechanical integrity.
Five internal knife-edge baffles are included to eliminate internal reflections and further enhance contrast. Compared to a similarly sized Schmidt-Newtonian, the Maksutov-Newtonian yields a sharper and more contrasty image. Naturally, the Maksutov-Newtonian is an excellent visual performer too!! The prices listed on this website are U. Prices may vary from dealer to dealer. Please contact your nearest stockist for firm pricing information.
As we are purely a distributor, we regret we are unable to sell directly to the public. Specifications subject to variation due to later production changes. No part of this website may be reproduced without the written permission of OVL. To me the Sky-Watcher range of instruments are very good indeed, and suited to amateurs of all kinds — and they are not priced out of the market!
Excellent value. Use them and enjoy them.Camera Lenses for Video – Understanding Lenses for Beginners (Focal Length, Aperture, Focusing)
Silicon dioxide produces a much more durable coat than silicon monoxide but requires specialized equipment to apply it and is therefore more expensive. Protection is needed, because in most reflectors, the mirror is open to the elements and deterioration of the reflective layer reduces the resolution of the telescope.The exciting new Maksutov-Newtonian from Sky-Watcher is just what astrophotographers and serious visual observers have been looking for.
The Maksutov-Newtonian design combines the best features from the Newtonian Reflector and the Maksutov-Cassegrain to create a telescope design that provides truly stunning image quality, providing high-contrast, perfectly flat images, free from false colour. The Maksutov-Newtonian design provides large aperture Apochromatic performance, with exceptional field correction, in a compact, amazingly affordable package. Stars appear as classic pinpoints across the entire field.
Perfectly optimised for modern DSLR cameras. The premium optics are housed in a robust rolled-steel tube for excellent mechanical integrity. Five internal knife-edge baffles are included to eliminate internal reflections and further enhance contrast. Compared to a similarly sized Schmidt-Newtonian, the Maksutov-Newtonian yields a sharper and more contrasty image. Naturally, the Maksutov-Newtonian is an excellent visual performer too!!
Be the first to Write a Review for this item! Phone lines and e-mails are open as usual. Catalogue Telescopes. Recently Viewed. No tweaking was needed at all, and there were pin sharp stars all the way out to the edge of the field. It really is like having a mm triplet apochromat in your hands, but for a fraction of the cost" Related Products Quick View.
Quick View. Company Registered in England and Wales. Company Registration No Continue Shopping. Add to Wish List. Tell a Friend.The focal length of the lens you use determines how the camera records the scene. A short focal length includes a wide view of the scene, which is why a lens with a short focal length is a wide-angle lens. Wide-angle lenses cover focal lengths from 12mm very wide field of view to 35mm.
A long focal length magnifies the scene, essentially capturing a small part of the scene or the field of view and magnifying it to fill the frame. Lenses with long focal lengths are telephoto lenses. Telephoto lenses begin with a focal length of 80mm and exceed mm. A lens with a focal length that is 50mm encompasses the same field of view as the human eye. A lens that encompasses a range of focal lengths is a zoom lens. You can zoom in on your subject to focus on a small area, or zoom out for the big picture.
You may see zoom lenses referred to as wide-angle to telephoto zoom, or normal to telephoto zoom. In essence, the focal length crops to a smaller area of the scene, which is the same as zooming in.
You can get closer to your subject without having to purchase an expensive telephoto lens with a long focal length. A full-frame sensor has dimensions of 36mm x 24mm. The focal length multiplier is also referred to as the crop factor.
The following figure shows two images of the same scene taken with two cameras. The image on the left was taken with a camera that has a full-frame sensor. The image on the right was taken with the same focal length on a camera with a sensor that is smaller than a 35mm frame of film.
Notice that you see more of the scene with the picture taken by the camera with the full-frame sensor. If you own a camera with a sensor smaller than a frame of 35mm film 36 x 24 millimetersthe sensor records only part of what the lens captures.
The net result is that the lens acts the way a longer focal length would on a full-frame sensor. Generally, the focal length multiplier falls in a range from 1.
Skywatcher Starlux 190 mm Maksutov-Newtonian Telescope OTA - S11550
If you place a lens with a 50mm focal length on a camera with a focal length multiplier of 1. If you put the same lens on a camera with a focal length multiplier of 1.
Nikon cameras without full-frame sensors have a focal length multiplier of 1. To find the focal length multiplier for the camera, divide the width or height of a 35mm frame of film by the width or height of your camera sensor.
In the case of the EOS 7D, 36 divided by Therefore, the focal length multiplier for that camera is 1.Shopping cart: 0 products Cash box Your account. Tau Atik. Photo Equipment Baader Baader. Adapter Barr and Stroud Berlebach. Solar DayStar. Solar DDoptics Dew Not. Lechner Electric Leica Binoculars and Spot. Meade Meopta Binoculars and Spo. SKMN in stock. Into the cart. VAT excl. The Sky-Watcher Maksutov Newtonian is a dream telescope for astrophotography with excellent field correction.
The telescope provides large aperture, high speed and excellent field correction.
SkyWatcher DS-PRO 190MN NEQ6 PRO Telescope
That are exactly the requirements for a dream telescope for astrophotography. Furthermore, the Maksutov-Newtonian also offers a very good visual performance with an image quality close to an apochromatic refractor.
We recommend the EQ6 mount for astrophotography. No reviews by eKomi at this time. The instrument immediately convinced with good sharpness over the entire field, so I exposed the Crescent Nebula 6x15 minutes, despite that the moon had risen in the meantime.
Imaging camera was the ATIK with 23 mm sensor diagonal. The Mak Newtonian provides excellently sharp stars over the entire format. High speed and good field correction allow imaging even fine structures in nebulae. I exposed a total of three hours through the Mak Newtonian. The telescope has maintaned sharpness optimally all the time. We sicerely congratulate to this outstanding result. Photograph from Uli Klein: 1.
Focusing using Bahtinov maks. One can see a large number of more distant galaxies in the field. M51 shows already the tidal bridge in the region of the companion NGC Everything purchased at TS. Photograph from Wavelet filtering and RGB alignment using Registax.
Here the surface of Jupiter already shows many details, in particular the Great Red Spot.