Cut Corners on a Ground Glass? Shen Hao XPO?

[mandonbossi]

Hi, I am interested in getting the Shen Hao XPO and was wondering if the factory GroundGlass comes with cut corners? I currently have a Chamonix 45N-1 with a Maxwell screen and I personally find the cut corners really annoying.. I know there is a reason they are there (to prevent vignetting?) but I think the missing corners of the image are more detrimental than an area where there is nothing.. I personally like an image that incorporates a full 5x4 frame and this can sometimes get in the way of this.. I remember reading somewhere it also has something to do with making sure the bellows don't create a vacum (or something like that) and also something to do with the screen being less likely to break if it was cut?.. Is there any other reason here that I am missing? I used to have a Linhof Tech 5 and i don't remember the corners being cut, although that was a while ago so I could easily be wrong on that one..

Can anyone see what other problems there are if I was to ask for a full glass screen?

Any suggestions or discussion would be greatly appreciated! Best Regards Mandon

[Lachlan 717]

I checked the back of mine. Small clipped corners. Probably 5-8mm. Can't seem to attach a photo from my iPhone. PM me and I'll send it to you.

[Joanna Carter]

Certainly, if the corners aren't clipped, it is very likely that you will create a sealed box where expanding/contracting the bellows will tend to deflate/inflate the bellows.

And, yes, they are very useful for checking whether you are going to vignette an image.

Personally, I don't see a problem with cut corners.

[Jim Jones]

You can also check for vignetting after the camera is set up, focused, and stopped down by looking at the ground glass through the lens. You should be able to clearly see the corners.

[Brian Ellis]

Unless you get a loupe with a square base such as the ones made by Peak, you won't be able to get into the corners with a loupe even if you have a ground glass without cut corners.

The only two reasons I've ever heard for having cut corners is the vacuum idea that Joanna mentioned and to allow you to check for vignetting from behind the camera. I've wondered about the vacuum theory because I'm not sure bellows are air-tight absent the cut corners. But I've never cared enough to buy a ground glass without cut corners and see what happens when I open and close the camera.

I use the cut corners to check for vignetting. While you can check for vignetting without cut corners by doing as Jim said, to me it's more convenient than going around to the front of the camera and peering through the lens.

[Len Middleton]

Certainly one might be able to install a ground glass without the clipped corners.

However for wooden cameras, the construction of the recessed area where the ground glass lies may not have the corners cut to the same level (i.e. not even or level with rest of area) depending upon how the recess was cut (circular saw blade, router, etc.).

Maybe one of our camera construction or repair types could confirm that bit of information...

[Ari]

I never noticed the vacuum effect on my 4x5, which does not have clipped corners, but my 8x10 came with clipped corners, and I hear a "whoosh" every time I extend or contract the bellows.
Maybe it's an issue with larger cameras?

[archer]

Dear Mandon;
The corners on my XPO GG are also clipped and it really comes in handy when using a compendium lens shade and movements of the front standard especially with wide angle lenses. The GG corners on the XPO are slightly smaller than on my Sinar and my old Iston.
Denise Libby

[mandonbossi]

Ok, seems nobody seems to have issues with the ole cut ground glass that I do..
Ari, was wondering what camera you have that doesn't have clipped corners? I generally use the viewcamera very simply i guess, without extensive movements, and I guess that seeing the whole image is more important to me.. I also seem to stop down to a degree where focusing in the corner is not such an issue but as previously noted, seeing the whole image is..

So I guess that if some camera makers are making them without the cut corners, then the issues can't be so severe with it..

So I guess when ordering it, I will just ask either Shen Hao or Bill Maxwell to make it that way.. Either that or get a glass with the corners and crop the image to a 5:4 format..

Thanks so much to everyone for all your help.

Best Regards

Mandon

[Joanna Carter]

So I guess when ordering it, I will just ask either Shen Hao or Bill Maxwell to make it that way

Don't forget that, if the corners of the recess for the screen are not cut dead square (slightly rounded) the corners of the glass might not sit within the curve of the wood. Also, you might limit how you can adjust the glass to get the grid square to the camera.

Either that or get a glass with the corners and crop the image to a 5:4 format

You really are making life hard for yourself - the full frame is already 5:4 (or 4:5) and it would be unusual not to crop a little bit when printing anyway.