Paul C. Buff, Inc. Technical Forum

I got the 45" octabox recently. I noticed that front diffuser doesn't seal properly on the velcro edges & the gaps on the corners are noticeable. It appears that the front diffuser doesn't have the right dimensions. Is the ill fit of the front diffuser normal? Thanks.

The fabric should fit and completely seal any gaps. However, The fabric will have to go on very carefully and straight. Any folds in the diffuser fabric velcro will effectivly shorten that side. This can have a cumulative effect sround the box and cause gaps. Also, you will want to place the fabric on the inside edge of the softbox's velcro, leaving a lip for grids (even if you do not want to use one). The outer edge of the box will have a longer circumference, which will also cause gaps if the fabric was placed there.

I'm laying down the front diffuser's velcro along the inside edge of the octabox velcro. I start with one of the corners but cannot get a good fit at the corners because of the bump at the corners. I tried several times & it always wind up being the same outcome with the gaps on the corners & along the straight edge. I must be doing something wrong. If I'm having this kind of difficulties in setting up the front diffuser, this octabox might not be for me then. I haven't heard anyone else having this issue. Very frustrating in trying to setup the octabox properly.

I start with the corners first. I use my thumbs to force the velcro around the bump you mention. The corner of the diffuser goes right smack on the middle of the bump.

After the corners are in I seal off the straight edges. It will never be perfect but I get it close. Any light leaking out would be inconsequential. You could verify this by aiming it a wall and taking a properly exposed picture of the pattern.

Pay attention to what TS said. It's designed to fit recessed in the box, as close to the silver inner lining as possible.

Thanks Brendan! Sounds like there will be always gaps. I'm planning to use it mainly during the daytime in the outdoors, the light leaks shouldn't even matter. The light leaks might be an issue if I was using it at night time or in a studio. I'll try setting it up again to see if I can get a better result.

I think I solved my problem with the front diffuser. I think I tried to mount the diffuser backward. I reversed the diffuser & it mounted properly. There are still some gaps but they are now on the corners but are a lot smaller in size. I didn't realize that there was a front side & back side to the front diffuser. Thanks everyone.