Chamonix 45n2 GG

[Bob McCarthy]

I purchased a new Chanomix during the latest release. In almost every way it is a really nicely done camera, I believe I got an exceptional value for my money.

The one weakness is the ground glass, doesnt come close to my Sinars. Or previous linhofs. It's not a brightness thing, but more a snap into perfect focus issue.

So what is everyone else doing??

Bob

[Steve Hamley]

Bob,

As a general rule I find that brighter, smoother screens and fresnels have less "pop" into focus, while coarser screens and plain GG have that "pop" but are not as bright and easy to compose with f:9 lenses etc.

Not really wanting to start a food fight, but I think a choice of screens/GG is a very personal thing, and you probably need to try something different. For example, can you put a Sinar screen in it? Probably.

Cheers, Steve

[Bob McCarthy]

For me its not as much pop but an exact point of focus, the tiny details get lost in the coarseness and focus is in a small range rather than at a specific point.

Its like all within the DOF, but when I have the bellows a bit twisted up Im not nailing focus on occasion. I get that there are compromises regarding ground glass. I should just order one from the man in the southeast and be done with it.

I think that is a good idea on the Sinar ground glass, I have a spare around here somewhere.

bob

[Steve Hamley]

Bob,

I find the same phenomena applies to fresnels - the brighter and finer they are, the harder they are to precisely focus, including the Maxwell on my 8x10 (came with it).

A nice, bright Maxwell is a joy to compose with, but in the end, it still - for me - doesn't focus as easily or precisely as a ground glass.

Another suggestion, a Steve Hopf ground glass. It will be darker than a fresnel and a pain in low light with f:9 lenses (like all GG versus fresnels), but I've had very good experiences with mine.

Cheers, Steve

[ashlee52]

I have just put a Steve Hopf GG into my Ansco 5x7... and I also have a Chamonix 45n1... the 5x7 is bunches easier to focus even playing the f6.8 Ektar on the 5x7 against an f 5.6 lens on the 4x5. Probably the image size has something to do with it but I believe the screen is brighter.

[Bob McCarthy]

I just remembered the old F in the cabinet has a Steve Hopt GG in it. Wonder if it fits.

Bob

[Steve Hamley]

Bob,

Let us know how things turn out with a ground glass after you've had a chance to assess the results - I for one am interested.

BTW, Don Dudenbostel who posts here has been a commercial and fine art photographer since the 1960s, and told me that he could not recall a professional photographer ever using a fresnel.

Cheers, Steve

[Jehu]

Doesn't the 45N2 have a correction built into it for the fresnel? If that's the case then it seems like a standard GG may be a little off.

Calling Hugo!

[Steve Hamley]

Jehu,

The 45N2 does have a correctly positioned fresnel as I understand it.

The discussion is really about whether a properly positioned fresnel is as easy to critically focus as a ground glass.

I've used both. My inexpert opinion is that I occasionally get mis-focused shots with a fresnel, and less often with a ground glass.

There could be a lot of factors in play since a fresnel is a lens. I suspect that not having your eye aligned with the loupe has more of an effect than if using a GG. Maybe tilting the loupe has a different effect with a fresnel vs GG. Take a pair of drugstore reading glasses and tilt them and look through them especially off center. Just an opinion. I've taken as sharp a picture with fresnels as I have with GG, but a fraction of the time, I don't, and that fraction seems greater than when using a GG.

I have no doubt that the Chamonix 45N2 fresnel is properly installed and don't want to start that discussion all over again. PLEASE, PLEASE don't start that all over again

Cheers, Steve

[Brian Ellis]

For me its not as much pop but an exact point of focus, the tiny details get lost in the coarseness and focus is in a small range rather than at a specific point.

Its like all within the DOF, but when I have the bellows a bit twisted up Im not nailing focus on occasion. I get that there are compromises regarding ground glass. I should just order one from the man in the southeast and be done with it.

I think that is a good idea on the Sinar ground glass, I have a spare around here somewhere.

bob

You're observing one of the major downsides of most Fresnel lenses - difficulty of focusing. The "coarseness" you mention comes from the lines in the Fresnel. The Maxwell screen is the only Fresnel I've used that was about as easy to focus as a plain ground glass and without the light fall-off when using wider lenses that ground glass usually has. I assume Maxwell is the "man in the southeast" you mention. If you can pay the price - about 25% of the cost of your camera - it's well worth it IMHO.