critical miniscope image problem

[Hyoung-Ro Lee]

Hi there.

I recently bought one of a fully assembled miniscope V4.4 from open ephys.

And I tested this miniscope.

but, the center and left side of the video of this miniscope is too bright. (I have attached the image.) So I couldn't see anything in the center and left.

Also Adjusting the gain and brightness makes it worse.

A labmaker's miniscope I bought didn't show this problem.

So I sent a complaint email to the opes.

but they don't answer my question for too long.

I will try to fix this miniscope myself.

Please give me some advice about this problem.

[Daniel Aharoni]

Hi. It is a bit hard for me to understand what we are looking at in the images you posted. Are you able to take an image with nothing in front of the Miniscope (having it face black electrical tape would also be fine). Can you also take an image of something that is clearly in focus? White paper, most hair, or jeans all should work well for this.

The for image is to get an idea of if this brightness you are seeing is due to excitation light leakage. The second image will just help us get a better idea of how your Miniscope is performing. Thanks!

[Hyoung-Ro Lee]

Hi. I  captured a few images using open ephys assembled miniscope to make the focus clear.

The first image is captured when there is no background. There is no background, but the image is bright in the center and left.

Next, I captured the hair. The hair is visible in this image but it's also bright in the center and left.

The last two images captured my jeans.

My miniscope image shows a bright center and left when there is nothing in the background.

What's wrong? please give me some advice.

2022년 6월 17일 금요일 오후 12시 38분 3초 UTC+9에 dbah...@gmail.com님이 작성:

[Daniel Aharoni]

Hi! This looks like a small amount of excitation light leaking to the CMOS image sensor. When you start to push the Miniscope to higher excitation LED values (~50 or greater) along with a maximum Gain, you will begin to see this light leakage. The leakage is due to optical filters not performing ideally with steep angled light (which will be present when using LEDs and short optical paths).

In practice, you should almost never need to run the system at this high of LED brightness and image sensor Gain. For example, our average V4 Miniscope CA1 GCaMP6f imaging uses and LED value of ~10 and a Gain of 1.

As a side note, the images you shared of jeans, for example, are also not in focus as you should be able to see individual strands of fabric really clearly. Make sure the Miniscope is held a little less than 1mm away from an object you are trying to image when doing some rough testing at the bench.

[Hyoung-Ro Lee]

Hi! Thank you for your answer.

I tried to set brightness under 10 to reduce light leakage. But this situation is not disappeared.

I attached some images. one is set at 5 brightness and another is 25. These two images were captured using opes miniscope which has some problems.

The last one was captured using labmaker miniscope(brightness is 50). Labmaker miniscope is working well.

I can't analyze opes miniscope data because of light leakage.

How Can I solve this problem?

[Daniel Aharoni]

Hi. Looks like an optical filtering issue with your OEPS scope. You can consider reaching out to them for a fix.