4x5 ground glass question

N

Nebular89

Messages
235
Edit My Images
No
Just got a MPP 4x5 to try out. The ground glass is pretty dark so if I enjoy it and stick with it I’ll be looking to replace it. Are all ground glasses the same size? The rear mount looks like a graflok? If that’s what’s it’s called
 

Attachments

  • 84E5B522-5333-47F3-90F3-B2433B1A0AE6.jpeg
    84E5B522-5333-47F3-90F3-B2433B1A0AE6.jpeg
    159.1 KB · Views: 11
There's a seller on eBay who does replacements, but I haven't tried or seen one. He's well known in the Large Format community (Ian Grant), so posssibly worth a punt?
www.ebay.co.uk

Large Format MPP Ground Glass Focus Screen 5x4 / 4x5 | eBay

MPP Ground Glass Focus Screen 5x4. To fit Micro Technical MkIII to MkVII, and Micro Press. The focus hood may not lock in place with a MkVIII. MPP Ground Glass Focus Screen 5x4. Graflex 5x4 Ground Glass focus screen.
www.ebay.co.uk
 
Last edited:
Before replacing the screen, do a search for "4x5 fresnel screen".

A suitable Fresnell will make your experience much brighter! ;)
 
Sky said:
I'm sure you know this already, but as this is new to you and just in case: You will need a dark cloth over it and your head, plus you will need to open the aperture to its widest to be able to view and focus the image (before setting the aperture to the setting you want).
Click to expand...
Yea, im using a thick jumper. It’s fairly unpleasant to use in this weather but it’ll do!
 
No they are not all the same, I suggest getting a Fresnel it makes the world of difference. I couldn't get one exactly the right size for my MPP but I got one that was close enoung and fitted with a little sandpapering
 
sirch said:
No they are not all the same, I suggest getting a Fresnel it makes the world of difference. I couldn't get one exactly the right size for my MPP but I got one that was close enoung and fitted with a little sandpapering
Click to expand...
Regarding the fresnel does focal length matter? One I looked at on eBay said it was best suited for lenses in the 150-250mm range. I couldn’t see why that would be the case but I don’t know much about them
 
Nebular89 said:
Regarding the fresnel does focal length matter? One I looked at on eBay said it was best suited for lenses in the 150-250mm range. I couldn’t see why that would be the case but I don’t know much about them
Click to expand...
I have no idea and it was not somehting that was mentioned or that I considered when I got mine which works on the lenses I have, that said I have 90-220 IIRC so not far out of that range
 
sirch said:
I have no idea and it was not somehting that was mentioned or that I considered when I got mine which works on the lenses I have, that said I have 90-220 IIRC so not far out of that range
Click to expand...
That’s what’s on his eBay page. I can only imagine it’s the image circle of the lens but I’ve never heard of it before
 

Attachments

  • 58863FCB-B3B5-4803-ADEC-FB43608EE348.jpeg
    58863FCB-B3B5-4803-ADEC-FB43608EE348.jpeg
    121.5 KB · Views: 8
Nebular89 said:
Regarding the fresnel does focal length matter? One I looked at on eBay said it was best suited for lenses in the 150-250mm range. I couldn’t see why that would be the case but I don’t know much about them
Click to expand...
They're offering two different screens on 5x7 for different focal length ranges, so I guess they think it does matter. You could email them and ask?
 
ChrisR said:
They're offering two different screens on 5x7 for different focal length ranges, so I guess they think it does matter. You could email them and ask?
Click to expand...
Yes it does make a difference, the correct fresnel screen for the focal length in use will make focusing easier the same can be said of focusing aids in any through the lens viewing system which is why high end SLR cameras had interchangeable focusing screens.

The fresnel lens in a large format camera will help direct light falling on to it to be transmitted to the viewer making the image brighter within the angles subtended by light from an optimised focal length range. Using the above fresnel with wider angle lenses than optimum will result in progressively less brightness and apparent visibility of the fresnel's rings to the viewer.

Sorry it my attempt at describing the above was a bit off the mark but it is a long time since I did optics, around forty years.
 
You must log in or register to reply here.
Back
Top