Parabolic reflectors

**Old Fart Scrogger** · 25-05-20, 06:56 AM

Here's a photo of the shadow
I don't know why the photo is not appearing. I've followed the exact same procedure as before, but no photo

**Old Fart Scrogger** · 25-05-20, 07:41 AM

Here's a photo of the shadow

Click image for larger version.

Name: IMG_0115 resized.jpg
Views: 33
Size: 185.8 KB
ID: 383590

,

**Krofam** · 25-05-20, 10:46 AM

oh, wow! thats proper noticeable.

i have never seen that before.

what bulb are you using?

could be that the reflective material aint as reflective as mine?

**Old Fart Scrogger** · 25-05-20, 11:13 AM

Hi Krofam, the reflector is a Lumatek Turrican. The reflective surface looks like a glass mirror. The lamp is a Sunmaster dual spectrum 600W HPS. When this photo was taken last year, the lamp was raised, to facilitate taking a downwards looking pic. So the shadow was larger. When the lamp is in the normal position, the shadow is the size of a dinner plate.
Shortly after I got the lamp / reflector combo, I did a grid survey under the light using a lux meter, and was surprised by the result. The reflector has 8 panels, joined together. Under the 8 joints in the reflector, the light level on the lux meter would be, say, 60 klux.
In between joints, i.e. under the centre of a panel, the light level would be typically 40 klux. I think this is a big difference. As a result of my survey, I also noticed that light levels were also a bit low in my "dinner plate" area directly beneath the lamp.
Therefore I train my plants to grow in a donut shape under the SCROG.
I think that the parabolic reflector is the best at the moment, but I would like something which gives a more uniform light.
Perhaps the Grostar reflector is better, but at £200?

**Krofam** · 25-05-20, 11:43 PM

\

i got one of these. a sunking parabolic reflector.white reflective material and vents on top which ive removed 2 blades from to widen it a bit.

even when i set mine at 4ft or more for access or when i clean, i dont get a shadow at all on the floor.

i personaly dont like the silver reflectors or sheeting. i preffer white.

also. the material that each panel is made from on the sunking, is very light weight and stays very cool.
my mate had one like yours and althgugh it didnt have the dark spot, the dish itself would get quite hot. and in general it seemed dimmer than mine.