Reduction lens for Microscope camera port - 0.3 or 0.5 - Page 1
Forum section: electronics / general

author: BinaryBits
author_rank: Contributor
timestamp: August 31, 2021, 09:34:26 am
content: I purchased an Amscope type Trinocular stereo microscope with a camera, but the camera FOV is much smaller than the eyepiece FOV.Im not sure if I should buy the 0.3 (1/3) or 0.5 (1/2) reduction lens for the camera port to get a FOV as similar as possible between the eyepieces and camera.If I read it correctly it depends on what die-size the image sensor is. My Hayear HY-5200 camera has a sensor size of 1/2.9 inch. Would the 0.3 be more suitable in my case then?Is that enough information in determining which reduction lens is most suitable in achieving a similar FOV between the camera and the eyepieces?If so, does anybody have the answer to that?Thanks in advance.

author: Electro Fan
author_rank: Super Contributor
timestamp: September 01, 2021, 03:42:42 am
content: Congrats on the new microscope!At the end of the post in this link is a table with some measurements that might help you. Some of the rest of the thread might also be relevant or interesting.https://www.eevblog.com/forum/beginners/the-ergonomics-of-microscope-soldering-direct-optical-view-vs-cameramo-257888/msg3332530/#msg3332530

author: jfiresto
author_rank: Frequent Contributor
timestamp: September 01, 2021, 09:25:40 am
content: A typical microscope camera port projects an image sized for a one inch sensor, so a guess from a great distance is you might want either.But there is no need to guess. Look at a ruler with the camera and through the eyepieces, and divide the longest length the camera can capture by the longest length you can see. The reduction you calculate may fall between, say, 0.3X and 0.5X. You can then decide which you prefer at the camera: maximum field of view or minimum vignetting.

author: BinaryBits
author_rank: Contributor
timestamp: September 16, 2021, 10:06:26 am
content: Update:So I received both the 0.3x and 0.5x reduction lenses. The 0.3 is very hard to get in focus, you need to lift it up a bit more with a shim, because otherwise it "runs out" of focus, you can only rotate the focus wheel so much. But the side effect of lifting it up is that you get this barrel look, with black rounded corners, the reason for this seems to be the small sensor size on my camera (1/2.9"), so with the more expensive cameras with bigger sensors this barrel look should not happen.The 0.5x lens works better but I still use a 2mm shim. Of course the 0.5x gives a smaller field of view than the 0.3 lens. So it seems the 0.5 was the right one for me, not the 0.3 as the below mentioned website suggested?.................................Thanks for your answers. Thats very helpful. I have a week or so ago ordered both the 0.3x and 0.5x reduction lens adapters since I found them for a good price, of course I don't know about the optical quality since they are from AliexpressA couple of days ago i came a cross a website, I think it was Olympus or Nikon which had a list of sensor sizes vs. reduction lenses, and it suggested for a 1/2.8" sensor a 0.3x was preferable (my sensor is 1/2.9").Thanks again for your answers.