I seem to have found a bit of an odd behavior on new-to-me Mamiya RB-SD with 6x8 power back. I took several test shots with this setup with back in PORTRAIT position. As you know, 6x8 is only supposed to be usable in portrait position, and not landscape. As this is an SD model, all of the bodies in market are supposed to be 6x8 capable. The light buffle does NOT have "8" on it but it was confirmed with Mamiya itself (I called) that it isn't supposed to be labeled as such and all SDs are already equipped with light baffles capable of this format. Looking at negative, all frames have one problem in common. All edges have the crisp border EXCEPT for the top of the image - which is bottom of the camera. The top edge has soft of a soft border. Thinking something may be lose and obscuring the light path, I looked inside. Nothing is obviously lose, misaligned or missing. This top edge of the image sort of look like when (printing on enlarger) you get too close to the image edge that border created by neg carrier falls inside the blade of easels. When this happens, it creates not crisply defined border. Images look just like that. I know this 6x8 capability on RB is sort of an after-thought by Mamiya. Is this how this was implemented and it's the way it is? Or do I have a problem? I know we have people on this board who uses 6x8 back... If you do, I'd like to hear from you.