NewbieQ: Do I need a better 8x10 ground glass

[Darin Boville]

Hey Guys,

I picked up that 8x10 Arca old-style that was posted here a while back (lovely camera, by the way)--it's my first 8x10, and I'm wondering if I need a better ground glass.

I'm using a Nikkor M 300 (all I have that covers 8x10, right now) and I can see the center portion of the image. I have to move around quite a bit to see the edges and corners.

Is this:

a) Just the way 8x10 is, buddy.
b) Duh, your lens barely covers 8x10.
c) Dump that old gg

Thoughts?

--Darin

[Gem Singer]

a.--Yes.

b.--Yes.

c.--No. Add a Fresnel screen, instead.

[John Berry]

You might also be able to see a little better by tilting the loop towards lens center, not flat on ground glass. Isn't it great to have a ground glass large enough you want to check milage on your loop.

[John Kasaian]

Is your lens open all the way to f/9 for focusing? Is your dark cloth dark enough? I'd look at those two things first. Focusing with the lens stopped down will always be dimmer because of less light being transmitted. Glare from a leaky dark cloth will nearly always make the ground glsss more difficult to see well enough o focus on.

I have a Nikkor M 300 on an 8x10 and it isn't the brightest compared to my other f/9 lenses IMHO, but it is a very nice lens and quite desireable.

If it is the ground glass that is giving you problems you can easily replace it or add a fresnel.

[henrysamson]

I agree with John . . . especially regarding the dark cloth. Mine is 3 layers thick and huge. I can get in there and load film it is so dark (just kidding).

Also, Is there any oil of any sort on the ground side of the ground glass. Make sure it is really clean but beware that some grids will clean off.

Henry

[Darin Boville]

O.K., here's an update.

There's no fresnel on the gg. It looks clean and new-ish otherwise.

My existing dark cloth is opaque enough but is far, far too small for 8x10. I see that I can greatly improve the evenness of illumination if I move my head much further back than I'm used to. Not perfect, but much better. My dark cloth doesn't allow me to go back far enough.

So, maybe I'll look into getting a fresnel--and certainly I need a new dark cloth. I'll do a search but if you have recommendations I'd love to hear them, especially those specifically related to the older-style Arca Swiss and to 8x10.

Thank for all the comments,

--Darin

[jeroldharter]

Darin,

I used the same lens on that camera. At the time, it was my only lens that would cover 8x10. I was surprised that it had plenty of coverage for my use. I found the ground glass to be average/typical. My new camera is about the same. I suspect that your dark cloth might be a problem. It is somewhat tricky to make it light tight because of the rail so you must take care that light does not leak in. You need a much larger darkcloth for 8x10. I have a Blackjacket which is the best I have found but opinions vary from using T-shirts to black Gore-Tex.

[John Kasaian]

A lot of light can be reflected up from the ground causing deterioration of the aerial image. You want a dark cloth large enough (if you're using a "traditional" horseblanket) to be able to gather the bottom edges of the cloth together with one hand with plenty of room for louping. You might try using an old raincoat and see if you're leaking darkness on the ground.
FWIW I don't have a fresnel on my 8x10 and as long as it is dark under there the aerial image is quite nice.