What is the difference between flip-up Loupes and TTL?
On flip-up Loupes, telescopes are not attached to the lens. The loupes and the telescopes are generally connected by an “arm” mechanism that attaches to the frame. With the “arm” mechanism, wearers can adjust the telescopes when needed.
TTL is the abbreviation of “through the lens”. TTL loupes are different in that they are truly custom-made for each user with the telescopes (oculars/magnifiers) literally set inside the lens and not allowed to be removed or modified.
Although there are a few other factors, the key difference in functionality comes down to the ability to adjust the Loupes.
TTL loupes are customized for each individual face. The customization involves the accurate measurement of the inter-pupillary distance (IPD) and the declination angle, as these data vary from person to person depending on how tall they are, how far apart their eyes are and their working ergonomics. Nose pads and temple arms can be slightly adjusted but it nearly makes no difference for another person. Therefore, it’s normal that you feel uncomfortable and ineffective when you wear others’ TTL loupes.
But when you try and use others’ flip-up loupes, things can be different as you can adjust the position of the telescopes to reach the proper IPD and declination angle.
Flip-up Loupes can easily overcome these obstacles for each individual as they can be adjusted to meet these varying requirements. Flip-up Loupes are so adjustable that you can even share them with other people. This flexibility may save some trouble when your loupes suddenly get lost or broken. However, these adjustments put on the weight of flip-up loupes.
TTL loupes, without the burden of the “arm” mechanism, are less heavier than the flip-up loupes.
In conclusion, flip-up loupes are usually heavier but more adjustable and shareable.
TTL Loupes are custom made for each face and feature lightweight and limited adjustments.
