Sorry folks I am panicing.
I got my lens back from the repairers Saterday, so put it on the camera and played with focusing the thing, using shifts to see what effect they had ect. ect.now the panic.
The image on the gg is quite dim, this I expected but the differance between the centre and edge is HUGE even with the lens wide open, Schneider 150 f5.6 and stopping it down to f22 makes it worse.
Q1 am I panicing unnessisarily and the film will sort it out.
Q2 am I doing something wrong.
Tried focusing useing a loupe and the Sinar rubber bellows and magnifier thingie same result in both cases. Am loth to start exposeing film untill I have sorted this .
Thanks and regards Paul.
Idiot question.
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Emmanuel Bigler
- Forum Hero
- Posts: 174
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Dim images !
Hello from France, Paul
Q1 am I panicing unnessisarily and the film will sort it out.
There is no problem. Probably you have a plain ground glass screen without Fresnel lens. If you are used to 35mm or medium format viewfinders, the image of a plain ground glass is quite dim in the corners but the film will record things properly.
In fact when stopped down to f/22 the image recorded on film is more uniform in terms of brightness between the centre and the edges than when wide open. At least this is what manufacturers publish in their technical data sheets. And it actually works (Schneider-Kreuznach is a reliable company, you know
)
For the 10x8" format you can add on top of your ground glass a plastic Fresnel screen size A4 that costs about 5 euro, say £ 3 ; you can find it at opticists' shops. For the 5x4" format you would need a similar Fresnel lens but smaller in size and with a focal length of about 150mm ; the A4 Fresnel lens has a focal length of about 300-360 mm, you could cut a 5x4" central portion of it but the focal length of 300-360 would not be the best and brightness improvements in the corners not the best possible.
I think that 5x4" Fresnel lenses can be found as accessories for view cameras, but the price will be substantially higher than £3.
Q2 am I doing something wrong.
Not at all ! Just take a picture and expose a film !
The best would be to meet other LF enthusiastas and see different ground glass systems !
Good luck !
Q1 am I panicing unnessisarily and the film will sort it out.
There is no problem. Probably you have a plain ground glass screen without Fresnel lens. If you are used to 35mm or medium format viewfinders, the image of a plain ground glass is quite dim in the corners but the film will record things properly.
In fact when stopped down to f/22 the image recorded on film is more uniform in terms of brightness between the centre and the edges than when wide open. At least this is what manufacturers publish in their technical data sheets. And it actually works (Schneider-Kreuznach is a reliable company, you know
)For the 10x8" format you can add on top of your ground glass a plastic Fresnel screen size A4 that costs about 5 euro, say £ 3 ; you can find it at opticists' shops. For the 5x4" format you would need a similar Fresnel lens but smaller in size and with a focal length of about 150mm ; the A4 Fresnel lens has a focal length of about 300-360 mm, you could cut a 5x4" central portion of it but the focal length of 300-360 would not be the best and brightness improvements in the corners not the best possible.
I think that 5x4" Fresnel lenses can be found as accessories for view cameras, but the price will be substantially higher than £3.
Q2 am I doing something wrong.
Not at all ! Just take a picture and expose a film !
The best would be to meet other LF enthusiastas and see different ground glass systems !
Good luck !
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masch
- Founder
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Paul,
What Emmanuel said
If in doubt, take a test shot to see what you get. Also, some fresnel screens are made for wide angle or tele lenses, resulting in significant apparent light falloff when looking t the screen (it's coming off at a different angle so you aren't noticing it...).
Try one and see. A 150 5.6 is not too dark, but if this is the first time you look at a GG it maybe a bit strange.
Did you try it outside or indoors? Indoors is usually pretty dark and a G image can be hard to see.
Marc
What Emmanuel said
If in doubt, take a test shot to see what you get. Also, some fresnel screens are made for wide angle or tele lenses, resulting in significant apparent light falloff when looking t the screen (it's coming off at a different angle so you aren't noticing it...).
Try one and see. A 150 5.6 is not too dark, but if this is the first time you look at a GG it maybe a bit strange.
Did you try it outside or indoors? Indoors is usually pretty dark and a G image can be hard to see.
Marc
Real Photographers use METAL cameras.....
...and break their backs in the process...
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...and break their backs in the process...
http://homepage.mac.com/mjjs/Photography/
Thank you thank you, was indoors pointing the camera out of the window, in the consevotary so pritty light.
Will take your advise and get on with it.
Did a test run on the self modified paterson reel and the film stayed in place and the extended reel didnot fall apart so think I have cracked developing the film. By extending the reel to 4inches it will take the film and fit my paterson multi reel tank, the type that takes 3x 35mm reels.
Am working on the meeting up bit.
All the best regards Paul.
Will take your advise and get on with it.
Did a test run on the self modified paterson reel and the film stayed in place and the extended reel didnot fall apart so think I have cracked developing the film. By extending the reel to 4inches it will take the film and fit my paterson multi reel tank, the type that takes 3x 35mm reels.
Am working on the meeting up bit.
All the best regards Paul.