Galilean telescopes Archives | Peter D'Arcy Optometrist | Bega Thu, 04 Aug 2022 06:48:10 +0000 en-US hourly 1 https://wordpress.org/?v=6.1.1 https://peterdarcy.com.au/wp-content/uploads/2019/04/favicon.ico Galilean telescopes Archives | Peter D'Arcy Optometrist | Bega 32 32 Magnification Loupes https://peterdarcy.com.au/magnification-loupes/ https://peterdarcy.com.au/magnification-loupes/#respond Sat, 30 Nov 2019 01:55:45 +0000 https://peterdarcy.com.au/?p=8132 Mini Loupes are designed to be ultra-light and comfortable. Standard Loupes: a larger field of view and a two-lens system Hi-resolution Loupes: bright image and larger field of view.  Prismatic Loupes: higher magnification and field of view.   MINI LOUPES LightweightExcellent imageQuality opticsGreat field of viewMini Loupes are ultra-light and comfortable with minimal compromise in …

Magnification Loupes Read More »

The post Magnification Loupes appeared first on Peter D'Arcy Optometrist.

]]>

TYPES OF SURGERY  LOUPES

Mini Loupes are designed to be ultra-light and comfortable.

Standard Loupes: a larger field of view and a two-lens system

Hi-resolution Loupes: bright image and larger field of view. 

Prismatic Loupes: higher magnification and field of view.

 

MINI LOUPES

Lightweight
Excellent image
Quality optics
Great field of view
Mini Loupes are ultra-light and comfortable with minimal compromise in the field of view.

Working distance and field of view

Working Distance Field of view
 34cm  7.5cm
 42cm  9.5cm
 46cm  10.5cm
 50cm  11.4cm

STANDARD LOUPES
All-round performance
Larger field of view
Two lens system
Weight – loupes on bar 46g

Magnification Working Distance Field Of View
 2.0x  34cm  11.4cm
 2.0x  46cm  15.2cm
 2.5x  34cm  8.1cm
 2.5x  42cm  10.0cm
 2.5x  46cm  10.9cm
 2.5x  50cm  11.8cm
 3.0x  34cm  5.9cm
 3.0x 42cm   7.1cm
 3.0x  46cm  7.7cm
 3.0x  50cm  8.3cm

HIGH-RESOLUTION LOUPES 3.0X Four lenses high index coated optical system.

Working Distance Field Of View
34cm 6.8cm
42cm 8.2cm
46cm 8.8cm
50cm 9.5cm

PRISMATIC LOUPES 5.5x have a more sophisticated multi-component optical system. 

The prismatic types use a double or Schmidt-Pechan prism to extend the optical path without significantly increasing the length and weight of the telescope body

Magnification Working distance Field Of View
3.5x 34cm 5.5cm
  42cm 7.1cm
  46cm 7.9cm
4.5x 34cm 4.6cm
  42cm 6.1cm
  46cm 6.9cm
5.5x 34cm 3.5cm
  42cm 4.7cm
  46cm
loupe types

Keeler loupes are flip-up design loupes only, not the TTL design.
In Zeiss, The GTX Loupes aren’t TTL so they would be classified as  FLM and the others as Flip Ups.
The Flips Ups are adjustable as the GTX is not.

The leading brands in  Australia are SurgiTel, Zeiss, Orascoptic, Heine and Keeler. Newer brands include Pentax, Bryant dental and Perioptix.
Orascoptic only does TTL (Through The Lens) Loupes. They do not do FLM (Front Lens Mount). Surgitel offers both TTL and FLM options. There are benefits to both TTL and FLM

We can advise on the correct magnification power of your custom loupe and lens coatings to reduce reflections, smudges, scratches and the less desirable blue wavelengths. 

Galilean telescopes are small and lightweight due to their relatively simple optical design.
Keplerian telescopes are longer and heavier as they incorporate prisms to reorient what would otherwise be an upside-down and inverted image. They give a wider field of view and higher magnification.

Keeler loupe field of view

Keeler surgical loupes have high-quality Schott glass and choices of flexible hinges providing an extensive range of declination to meet procedure and posture needs.

For the spectacle wearer, you can choose to wear your spectacles under the Keeler frame or use the RX lens holder for your prescription lenses.

We can advise recommended working distances based on your height, prescription and posture.

keeler loupe wearing options

SURGICAL LOUPE FRAMES

loupe-declination angle

Frames need to be suitable for the loupe.

Wrap frames properly designed are often used with safety shields.
Protection by lightweight plastic splash guards can be easily detached when not required.

The Keeler headband offers adjustable nose pads.

Protective and one dioptre distance caps protect the front lens. Powered caps will allow even more magnification but will change working distances.

 The loupes removable flip lever and protective caps are easily removed and are designed to be autoclavable to ensure biosafety.

The correct posture, viewing angle and ability to see usually are the benefits of ‘flip up’ loupes as a three-way adjustable hinge allows positioning as required.

TTL LOUPES VERSUS FLM LOUPES 

Orascoptic only does TTL (Through The Lens) Loupes. They do not do FLM (Front Lens Mount). Some companies, e.g. Surgitel offer both. There are benefits to both TTL and FLM. TTL allows the ocular to be closer to the eye, providing a larger field of view. They are also set in one position, so no adjustments to be made. TTL loupes are custom-made for each client. FLM loupes are adjustable and offer a high declination angle that reduces head tilt.

The manufacturing process of TTL loupes is very complicated, and the loupes will only fit the measured client. The ocular height in the frame depends on the bridge of the nose and how the frame sits on the client’s face. The width between the oculars depends on the client’s interpupillary distance, and the eyes are also not always symmetrical on both sides of the nose, so there is a left and a correct side measurement. The angle that the oculars are mounted in the glass is related to the working distance for the client, and the two images need to ‘converge’ at the correct length to give one single image. This will also vary depending on the prescription for the client. The convergence will also vary depending on the head width of the client, as the head width will ‘flex’ the frame when worn, which will change the convergence angle. These measurements are critical to getting a working solution with TTL loupes, and the measures become more critical with higher magnifications. That’s why FLM loupes are so easy, as most of these things (except convergence) can be adjusted by the user.

A CNC machine to mill the holes (not done in Australia) and a laser alignment bench to align the oculars before gluing are required to fit oculars into a prescription lens. Zeiss type can be cemented to the front of the lens, removed, and realigned if needed.

Surgical loupe illumination

Play Video about flip up loupe

We can advise on the led headlight required. The Keeler Loupe Light is one of the smallest and lightest available. The LED illumination gives 34000 Lux of homogenous white light, ideal for surgical and dental use, while coaxial illumination ensures shadow-free viewing. An optional yellow filter avoids the premature hardening of composites.  The lithium-ion battery will give up to 7 hours of continuous use before a recharge is required.

The post Magnification Loupes appeared first on Peter D'Arcy Optometrist.

]]>
https://peterdarcy.com.au/magnification-loupes/feed/ 0