Focusing problems with the fresnel groundglass on the Chamonix 45N-1?

[Hugo Zhang]

Hi Guys,

As I annouced in our website a few weeks ago, we are fully aware of this problem and are working to solve it. We apologize for the inconvenience this has casued to our users. Our designer has returned back to the factory from a long trip in Tibet and we will look at every possible solutions to this and we expect to annouce something soon in our website.

Everybody should know that we use fresnel lenses only on our 45 cameras. Other camera models are not affected since there are no fresnel lenses on them. Rumors of this problem in other models were invented by one person who has never used our camera.

Thank you for your support and patience!

[Songyun]

According to another thread the very same problem for the very same reasons exists also on their 5x7 and 8x10 cameras of the same kind as the 45N-1.

According to what? As far as I know fresnel is only supplied with 45N-1 cameras. 57 and 810 has ground glass only. (I have an 810, which doesnt have the slot for fresnel)As mentioned by a lot of ppl here, as long as you removed the fresnel, the problem is solved. You can bash Chamonix as much as you can, but get your fact straight!

[Mike1234]

Hugo,

Thank you for posting a reply. Will Chamonix offer a solution to remediate this issue for all existing cameras with this problem at no cost to the customer?

[GPS]

According to what? As far as I know fresnel is only supplied with 45N-1 cameras. 57 and 810 has ground glass only. (I have an 810, which doesnt have the slot for fresnel)As mentioned by a lot of ppl here, as long as you removed the fresnel, the problem is solved. You can bash Chamonix as much as you can, but get your fact straight!

According to the thread "focusing error", in the post n.16 by shadowleaves:

Ok, here comes THE answer....

This a design fault that exists on EVERY chamonix camera that uses a Fresnel, namely the 045n1, 057n1, and a few other models. YES, your 045n1 does have this focus shift.

I should have posted this in a separate post. I posted a while ago about this in a Chinese forum, that I did a thorough investigation into the focusing error of Chamonix 045n-1 cameras. My conclusion is that clearly the factory alignment calibration is done without fresnel on the ground glass (which was confirmed during my chat with Mr Xiang Yu, the owner of Chamonix and designer of all Chamonix cameras), yet their cameras are shipped with a fresnel placed between the ground glass and the lens.

This apparently causes the focus shift, usually about 1/3 of the thickness of the fresnel.

The problem can be easily illustrated by this pic. I drilled a hole in the center of the fresnel of 045n1, and capture the focusing results using my D50 camera and a macro lens. Clearly, the fresnel is the only cause of the focusing shift. If I focus through the hole that I drilled, or without fresnel completely, the focus will be perfectly accurate.

This in my opinion is the biggest fault in 045n1's design. I communicated with them about this, but unfortunately they think the users are going to use below f/32 for landscape anyway so it won't be a big practical problem in their opinion. I'll leave that up to you guys to decide whether you want to drill a hole in the fresnel or to remove it completely or to live with the focus error.

[GPS]

Hi Guys,

...
Everybody should know that we use fresnel lenses only on our 45 cameras. Other camera models are not affected since there are no fresnel lenses on them. Rumors of this problem in other models were invented by one person who has never used our camera.

Thank you for your support and patience!

Hi Hugo,
everybody would surely know if somebody like you cared to correct the error (see the mentioned thread) when posted. Pity that you knew about the posted error and its source and let it be...

[GPS]

Hi Guys,

...
Everybody should know that we use fresnel lenses only on our 45 cameras. Other camera models are not affected since there are no fresnel lenses on them. Rumors of this problem in other models were invented by one person who has never used our camera.

...

??? Shadowleaves seems to speak as a person who has and uses the camera ... See his post.

[Songyun]

??? Shadowleaves seems to speak as a person who has and uses the camera ... See his post.

He has 045N-1 but not 057N-1.

[iamjanco]

The only cameras spec'd out with a fresnel on Chamonix's web site are the 4x5 & 5x8. That's not to say the others don't ship with a Fresnel, just to say that only these two models appear to do so.

Jan C.

[shadowleaves]

??? Shadowleaves seems to speak as a person who has and uses the camera ... See his post.

I only have 045N1. I've not used any Chamonix 5x7 models so my experience applied for 45N1 only.

[GPS]

I only have 045N1. I've not used any Chamonix 5x7 models so my experience applied for 45N1 only.

"This a design fault that exists on EVERY chamonix camera that uses a Fresnel, namely the 045n1, 057n1, and a few other models. YES, your 045n1 does have this focus shift."

Can you explain??