Vertical bands when overexposed, diagnose?

malveaux

Hello,

I'm new to this camera, its an ASI174MM (non-Cooled).

I installed the latest drivers (as of today), and I fresh installed the latest versions of SharpCap 2.9 and FireCapture 2.5.

ZWO ASI Driver version: 2.0.1.3

SharpCap Version 2.9.3055.0

FireCapture Version 2.5 x64

The camera works and is able to display and record properly when my exposure values and resulting image do not involve anything clipping highlights (overexposing to pure white; the far right of the histogram). The moment my exposure values allow for highlight clipping, or over saturation of the pixels basically to white, I get a strange vertical set of bands. The bands seem to be static, and as I move the camera, the bands seem to be "behind" what is not over-exposed.

These bands remain vertical even when I rotate the camera.

I've tried two different USB3 cables, that function just fine with my other ASI camera too. This only occurs with the ASI174MM and it only shows up when I'm over-exposing.

This is a specific problem with solar imaging because I often over-expose to image prominences, and when the vertical bands show up during over-exposure, I cannot see much due to that, and it records it that way, so the resulting video & still images from them all have the vertical images in them.

I've attached a screen shot of what these bands look like from a video I captured and loaded into AS!2, and how it was captured into the video, and during conditions when they are there (in the very exposed section of the solar disc when looking for prominences). I can recreate it on two different computers, latest drivers, two different cables. It always happens when I over-expose no matter what it is (even a light in my house, see next post).

Looking for some help.

Thanks!

Very best,

malveaux

Here's another example in the acquisition phase, using SharpCap 2.9 and the latest ASI drivers.

Here, I've pointed the camera through a lens at my ceiling, with a light. I exposed everything around it and let the light over-expose so you can see the behavior of the vertical bands in the over-exposed area (on the light) and how it halos around things as they become over-exposed or over-saturated.

Note, when I rotate the camera, the lines remain vertical!

And here's the camera settings log just in case:

Pan=0

Tilt=0

Output Format=AVI files (*.avi)

Binning=1

Capture Area=1936x1216

Colour Space=MONO8

Temperature=42

High Speed Mode=Off

Turbo USB=80

Flip=None

Frame Rate Limit=Maximum

Gain=100

Exposure=0.005

Timestamp Frames=Off

Brightness=1

Gamma=50

Auto Exp Max Gain=200

Auto Exp Max Exp=30

Auto Exp Max Brightness=100

Subtract Dark=None

Display Brightness=1

Display Contrast=1

Display Gamma=1

Image attached.

Very best,

malveaux

More data to look at and examples.

One is of the acquisition phase, in SharpCap 2.9 with latest drivers.

I over-expose the disc to see prominences in HA.

But, anymore exposure and the vertical bands bloom out around the disc and hide prominences.

The other is of a narrow FOV of prominences on the limb of the disc, here, I am able to keep the over-exposed disc surface away from the prominences and separate them enough to image and see them.

Very best,

merlin66

Hmm

If the lines ALWAYS appear vertical independent of the camera angle I can only assume it's a display issue with your monitor.....

malveaux

Merlin66 wrote:
Hmm

If the lines ALWAYS appear vertical independent of the camera angle I can only assume it's a display issue with your monitor.....

Then how is it in the recordings? On two different computers?

Very best,

Sam@ZWO

we suggest exchange this camera from where you bought

seems some hardware problem

malveaux

Sam wrote:
we suggest exchange this camera from where you bought

seems some hardware problem

Wow, that's not good.

No other suggestions on what to diagnose?

Is this repairable? I think its been a while for a return. No one would ever know of this defect in the camera unless they were over-exposing an object, such as specifically imaging prominences in hydrogen alpha.

Very best,

merlin66

I use the 174MM for solar imaging....

I've done some overexposed shots, like you, to record the proms and haven't seen the defect you show.

I use an MSI i7 computer with USB3 (direct), SSD drive and 32Mb memory.

Usually with FireCapture.

Sam@ZWO

MalVeauX wrote:
Sam wrote:we suggest exchange this camera from where you bought

seems some hardware problem

Wow, that's not good.

No other suggestions on what to diagnose?

Is this repairable? I think its been a while for a return. No one would ever know of this defect in the camera unless they were over-exposing an object, such as specifically imaging prominences in hydrogen alpha.

Very best,

yes, it's repairable, this is suppose to be one solder problem

you can send it back directly to us for repair too

you can contact us through email if you wish