Yanke Fresnel Question

[mircea nicolae]

Hello,

I would like to change my Ground Glass / Fresnel that came with my Shen Hao TFC45 IIB camera.
https://www.badgergraphic.com/store/..._detail&p=3165

I found a bright Ground Glass / Fresnel on Ebay that might work.
http://cgi.ebay.com/ws/eBayISAPI.dll...X:eRTM:US:1123


However, I am a bit confused by some technical questions.
I made diagrams for three types of setup - Ground Glass only, Ground Glass and plastic Fresnel, and Yanke Fresnel.




1.Considering my drawings, where is the sheet film plane? Is it:

a. on the plane of the Glass holder (number 5 on my drawing)?
b. or on the plane of the Fresnel holder (number 6 on my drawing)?


2. My guess is that if the film plane is on the plane of the Glass holder (number 5 on the drawing), that means that the Yanke Fresnel / GG I would like to buy will displace the focus plane by 1.5 mm towards the lens, because the image is formed on the matt layer facing the lens. Is this so?

If it is, it would mean the brighter Yankee Fresnel / GG would actually be less useful than what I already have installed on the camera.
Please tell me if I am missing something.


3. On my Shen Hao camera, the dimensions of Ground Glass are different from the Fresnel.

• the Ground Glass is - 127 mm x 101 mm
• the Fresnel is - 123 mm x 101 mm

Each of them has a distinctive slot into which they are placed. The guy on Ebay seems to be completely confused as to the need to have different measurements on the Protective Glass and on the Fresnel.

a. If any of you have bought and installed a Yanke Fresnel / GG on a Shen Hao, what is your experience with this?
b. Does the Protective Glass come in a wider size than the Fresnel, so that it actually fits the camera?


4. When you received the Yanke Fresnel / GG, did you have to peel off some layer of plastic from the Fresnel?



I know I am asking many questions, so any info would be appreciated.


Thanks.