Rendering glass against a screen

i noticed that when rendering glass that is close to a background its really really slow, is there some option to speed up the renderings, without glass its like a 15 minute render but with glass like 3 hours so any help would be appreciated, i should also state it just a black material with full reflection and glossiness and refraction at full white also and default values, only there is a fog color but even before changing the fog color it was stil really long times and its a 2.5k res render

Not sure what you mean. Need better screenshot of the glass and the “background”. Also your material settings. Make sure affect shadows are ticked for refRaction

Could you attach or send us this glass part of the scene?

uff, you guys are like spying on me, i was just about to send you the scene, lol, here just about to open it:)

here is the image, the glass is actually in the area in blue, just infront the blinds but it renders on my side alot slower with the glass and yea it has affect shadows ticked

Is dispersion enabled? (Abbe number)

no its not, am wondering if its the close proximity to another object maybe, i have seen something like this before but it was long time ago with a closet door but i think that was maybe 4 years or so ago

Did you find out what it was? I’m interested to know what caused this to ensure I can handle it on my scenes in the future.

O sorry, chaosgroup said its normal, my scene was really just one window, a product render but they said default settings were too high, which means its not so good to really use default settings and they advised to use the denoiser and lower settings, i dont see this with normal windows in interior renders or exteriors so idk,if they said its normal then its normal

Oh, OK. I mean, 20 minutes render time to 3 hours sounds abnormal to me. But fine, let it be so for right now, I guess. Do you use a plane or a box when you apply the glass material? I try to use a box, and add Reflect on both sides.

Well i reduced my settings but i normally just use a box with normal glass thickness up to 1/4 inch and apply a glass material