Any help with G690 rangefinder?

[ryansholl]

I mean the rangefinder literally. I picked up a very well used, for parts G690 with a 65mm lens off ebay for a steal. I have managed to get the winder working again and have cleaned up the hazed element in the lens. Also picked up a "for parts" 100/3.5 AE for very little and it appears to work fine! Hooray for sellers not having equipment to test on!

I did my best to realign the rangefinder, of which the main element was loose, according to the focus distance scale on the 100mm lens. I do not have the dedicated plunge micrometer with the infinity measurement specified in the repair manual. However I do have a standard plunge micrometer.

Thus, I have two questions:

1) Would anyone know what the actual depth measurement is for the infinity setting as specified in the user manual and

2) If not, how well can I trust the focus distance scales on the lenses?

I am leaving the 26th for a month in the Philippines and Japan and am carting the camera around primarily for the 65mm lens and landscapes, so getting the rangefinder alignment perfect isn't of much concern. However, if I feel I can trust it to get focus right I'll be taking the 100mm as well and using it for a great deal more!

I'm not scared of wasting a few rolls of film.

Thank you all for any help you can provide!

 

[kuzano]

use a ground glass calibration method....

use a ground glass calibration method....

I mean the rangefinder literally. I picked up a very well used, for parts G690 with a 65mm lens off ebay for a steal. I have managed to get the winder working again and have cleaned up the hazed element in the lens. Also picked up a "for parts" 100/3.5 AE for very little and it appears to work fine! Hooray for sellers not having equipment to test on!

I did my best to realign the rangefinder, of which the main element was loose, according to the focus distance scale on the 100mm lens. I do not have the dedicated plunge micrometer with the infinity measurement specified in the repair manual. However I do have a standard plunge micrometer.

Thus, I have two questions:

1) Would anyone know what the actual depth measurement is for the infinity setting as specified in the user manual and

2) If not, how well can I trust the focus distance scales on the lenses?

I am leaving the 26th for a month in the Philippines and Japan and am carting the camera around primarily for the 65mm lens and landscapes, so getting the rangefinder alignment perfect isn't of much concern. However, if I feel I can trust it to get focus right I'll be taking the 100mm as well and using it for a great deal more!

I'm not scared of wasting a few rolls of film.

Thank you all for any help you can provide!

PHooey on all those micrometer instruments. On my G series 690 cameras. I set up three focus resolution targets. One at four feet, one at 15 and one at 45.

I open the camera back to tape a piece of GG (matte side forward) cut to 6X9+. Tape the GG onto the film plane. Put the camera on a tripod. Focus the lens on the ground glass (take a look at the distance scale on the lens for reference). If you are focused on the four foot target, adjust the RF to match the patches. Follow up for the 15 foot mark, and for the 45 foot mark.

In the absence of a real section of GG, I have used a flat panel cut from a tupperware taped to the film plane... matte side forward and accomplished the same "spot on" results.

 

[ryansholl]

Well. As someone that does not have a section of ground glass, this is actually amazingly convenient.

I'm headed home for Thanksgiving. I had already planned to do exactly the distance calibration you described. My mother owns and operates a stained glass shop out of her house. I have all necessary tools/materials for painting cars. Glass + fine grit = ground glass!

I'm learning stuff all the time with this camera. You have saved the day, kuzano. Thank you immensely.

 

[kuzano]

I also use this method on old folders...

I also use this method on old folders...

Well. As someone that does not have a section of ground glass, this is actually amazingly convenient.

I'm headed home for Thanksgiving. I had already planned to do exactly the distance calibration you described. My mother owns and operates a stained glass shop out of her house. I have all necessary tools/materials for painting cars. Glass + fine grit = ground glass!

I'm learning stuff all the time with this camera. You have saved the day, kuzano. Thank you immensely.

I worked out this method when I was messing with old front cell focusing folder camera's. It works great for setting up 3 -4 distance target intervals and using the ground glass on the film plane of the folder. Focusing the distances and marking them on the rim of the front cell.

I also used to restore old brit cars, and then eyetalian... alfa, fiat, etc. and had a paint shop set up at my home. When it got to the point that I was working on other people's cars more than my own, I bagged the shop and sold all the tools. It was great fun while it lasted... 10-12 years.

 

[ryansholl]

Kuzano, just wanted to thank you. Hopefully the few rolls I ran through the camera turn out. I have a legitimate piece of ground glass coming to retry

With a little help from bearded lego man

My younger brother playing with his new camera as I played with mine

Thanks again.