90mm f6.8 vs f8 lenses

[Meekyman]

Thanks Everyone,

I was leaning towards a Rodenstock/Caltar 90mm f6.8 and everything so far supports that.

In terms of the fresnel and ground glass and their effectiveness, well I am using a Chamonix 045n-2. I'm too new to this to know if that camera has a good/bright fresnel or not!

Cheers

Graham

[Doremus Scudder]

To summarize the above:

It all boils down to optimizing a few parameters for your particular needs: coverage, size and image brightness. If you need light and small and don't plan on using any movements, then an Angulon 6.8 will work well. It has a fairly bright image at f/6.8. (I have a similarly-sized Wide-Field Ektar 100mm that I use when size is a big issue).

If you need more coverage but still place a premium on portability, one of the f/8 Super Angulons (or the equivalent from Nikkor and Fuji) will suit you just fine if you can live with the slightly dimmer image (BTW, I own an f/8 Super Angulon 90mm and it is "just right" for me. It's my standard 90mm).

If you need lots of coverage and can live with a larger lens, and especially if your eyes need the brighter image, then one of the f/5.6 versions is what you want.

The Rodenstock Grandagons fall somewhere between the other designs in terms of maximum aperture. However, you can think of the f/4.5 and the f/6.8 as slightly brighter versions of f/5.6 and f/8 respectively since the other specifications are similar.

Your Chamonix, if it came with the Fresnel, should be close to as good as it gets in terms or ground-glass brightness. I have 4x5 cameras with and without Fresnel screens and use lots of f/8 and f/9 lenses with no problems, even in rather dim lighting. A good dark cloth and time to let your eyes adjust help a lot in this regard.

Best,

Doremus

[Meekyman]

Thanks Doremus for that summary...really helps.

Sure, my Chamonix came with the fresnel and I have a good dark cloth, a BTZS tube, and decent eye-sight. I will stop worrying unneccessarily!

Cheers

Graham

[IanG]

I agree with Dave, I have a 90mm f6.8 Grandagon and a 90mm f5.6 Super Angulon and that differenance in brightness in minimal with the SA. I prefer the Grandagon they are superb lenses it's one of my favourites. The SA was bought for 6x17 camera but now sits with my second 5x4 kit usually left in Turkey.

Ian