Does a field flattener reduce focal length?

The former will leave the focal length of the telescope essentially unchanged whilst the latter will reduce the effective focal length by 0.8x, 0.7x or 0.6x, as well as flattening the field – these will both widen the field of view and reduce the focal ratio so shorter total exposures will be required.

What does a telescope focal reducer do?

Focal reducers are primarily used in astrophotography to compress the light cone exiting the telescope down to a size closer to that of the sensor within your camera. This also results in a brighter image which reduces the exposure time.

Can you use a focal reducer on a refractor?

Focal reducers for refractors are easy to use. They usually have a 2″ barrel that slides into the telescope focuser. The telescope side of the barrel is often threaded with an M48 x 0.75 thread for standard 2″ astronomy filters.

How do I choose a focal reducer?

This factor is designated by a power that is less than 1, and it usually lies between 0.5x or 0.8x. For example, with a 0.8x focal reducer, a telescope with a focal length of 800mm will operate at 800 x 0.8 = 640mm when the reducer is placed at the working distance specified by the manufacturer.

What does a flattener reducer do?

Field Flatteners And Reducers Some flatteners do just that: they flatten the field removing the field curvature created by the telescope. Some flatteners are also reducers: this means that while they correct the field curvature, they also reduce the focal length of the telescope.

Are focal reducers worth it?

Yes, focal reducers are worth it. The f/6.3 is $120 and the f/3.3 is $150, for the Meade ones. I have an f/3.3, but it is ONLY for CCD use… i rather discovered that fact the hard way. However, it has been invaluable for imaging; at f/10 I would not have attained the required wide field.

Is a field flattener necessary?

To use a telescope for photography an optical device is needed to convert your telescope from a visual instrument to a photographic camera lens. This optical device is a field flattener (or reducer/flattener). Without a field flattener stars that are not in the center will appear distorted. Spacing is critical.

What is a focal reducer flattener?

It allows you to image larger areas of the sky with a DSLR camera and lets you fit a larger range of objects onto the small imaging area of a DSI-type camera or CCD camera’s imaging chip. For example, an f/6.3 focal reducer on an 8″ f/10 SCT cuts the focal ratio to f/6.3, reducing exposure times by about 60%.

Why do I need a field flattener?

Field flattener lenses in binoculars improve edge sharpness and lower the distortion. Field flattener lenses counteract the Petzval field curvature of an optical system. In other words, the function of a field flattener lens is to counter the field-angle dependence of the focal length of a system.

What does the Tele Vue focal reducer and field flattener do?

This Tele Vue 0.8x Focal Reducer and Field Flattener works in conjunction with TV-85 and Pronto telescopes. Transforms the TV-85 into a 480 mm f/5.6 system, and the Pronto into a 380 mm f/5.4 system. Flattens the field in addition to reducing the effective focal length for fast, superior quality astro-imaging operations.

What is a focal reducer and how does it work?

A focal reducer, also known as a telecompressor, effectively reduces the focal length of your OTA, resulting in a wider field of view. They are also a great addition to any astrophotography set up as it can cut your exposure time down considerably.

Will This reducer/field flattener work with the Astro-Tech at72ed?

While this Astro-Tech #ATR8 0.8X reducer/field flattener is designed for prime focus astrophotography with quality f/6 focal ratio apo refractors such as the Astro-Tech AT72ED and AT130 apo, it will also work well with Astro-Tech and other brand refractors in the f/5.5 to f/7 range that use a 2″ focuser.

How do I reduce the focal length of my Telescope?

Decrease the focal length of your telescope by half with this 2″ 0.5x Focal Reducer. Provides a wide field while minimizing exposure times for astrophotography. This 2″ 0.5x Focal Reducer contains fully multi-coated optics with two-element optical design.