Bessa II sharpness problem

FallisPhoto said:
As Andrew says, some play is normal and the camera would have to be very worn for this to be the problem. Looking at your photo, I don't think this is what's wrong. I really do think you need to backsight your camera. Basically, you tape a piece of ground glass, with a thin black asterisk shape drawn on it, to the film plane. You set the camera on a tripod with an SLR looking into the lens from another tripod. Adjust the SLR's lens to infinity and adjust the focus on your Bessa. When you can see the asterisk shape most sharply in the SLR's viewfinder, the rangefinder's lens is properly adjusted for infinity. Both lenses have to be focused for the same distance in order for you to see a sharp asterisk. I'd bet yours is off.
Click to expand...

I have never tried the SLR method but I checked with some atennas far away using a ground glass on the Bessa. The SLR method is worth trying. Since I have some sharpness in the center and unsharp away form the center the lens is probably not parallel? .....if make asterix also in the corners I should be able to see this.

The scanning is done on a Nikon 9000 using glass holder.....so scanning results is what I also see using a magnifier on a light table.

Thank you so far with your comments and suggestions. If the pressure plate has pressure enough it should be able to hold the film so it can't "pull back".

I have just made some test images using a 6x9 Linhof Techinka with a brand new Super Rollex back. Results here are very different and I noticed that advance mechanism does not allow the film to "pull back". But of course it is another level of camera.
 
sevo said:
To infinity - that is the basic rule of collimation!

To calibrate lenses to other distances with a collimator, you'd have to put a concave lens into the beam (or put the collimating lens to distances beyond infinity - but that would need yet another calibration reference, so it is rather less useful for home testing). I.e. collimation for closeup is nothing you can improvise to defined standards at home, unless you get hold of a suitable high precision concave achromat.

Sevo
Click to expand...

Well, yeah. That's why I said to adjust the SLR's lens to infinity.
 
MXP said:
Since I have some sharpness in the center and unsharp away form the center the lens is probably not parallel?
Click to expand...

Is it unsharp to every side, or is there a sharp vertical or horizontal line in the center? The latter would be a indication of lens skew on that plane, the former is more likely due to improper shimming of the lens or some error with the element ordering and orientation - many of these lenses have suffered amateurish cleaning attempts in the past.

Sevo
 
sevo said:
Is it unsharp to every side, or is there a sharp vertical or horizontal line in the center? The latter would be a indication of lens skew on that plane, the former is more likely due to improper shimming of the lens or some error with the element ordering and orientation - many of these lenses have suffered amateurish cleaning attempts in the past.

Sevo
Click to expand...

I have downsized the image to 4000 pixels width. I you look it in original it will load a 3MB JPEG. Don't know if this i useful?

http://www.pbase.com/mxp/image/110104429/original
 
MXP said:
I have downsized the image to 4000 pixels width. I you look it in original it will load a 3MB JPEG. Don't know if this i useful?

http://www.pbase.com/mxp/image/110104429/original
Click to expand...


Sharp on the right and blurred on the left; looks like you may be right. One thing though: I've had a few cameras sent in for repair over the years whose owners complained of similar problems. Only one of them had a loose standard (due to wear and a bent strut, which problems were not difficult to fix). The others all had loose lens elements. I know it is a rookie thing to overlook, but I'd check it anyway.
 
FallisPhoto said:
Sharp on the right and blurred on the left; looks like you may be right. One thing though: I've had a few cameras sent in for repair over the years whose owners complained of similar problems. Only one of them had a loose standard (due to wear and a bent strut, which problems were not difficult to fix). The others all had loose lens elements. I know it is a rookie thing to overlook, but I'd check it anyway.
Click to expand...

I must see what I can do. It was the intention that the houses on the other side of the road should be sharp. I also think that the right side is quite unsharp. Normally the street signs should be easy readable. I don't know how good the lens is in the far coners. Probably the sharpness is not to good on such an old lens (Color-Heliar in this case).
 
MXP said:
I must see what I can do. It was the intention that the houses on the other side of the road should be sharp. I also think that the right side is quite unsharp. Normally the street signs should be easy readable. I don't know how good the lens is in the far coners. Probably the sharpness is not to good on such an old lens (Color-Heliar in this case).
Click to expand...

Okay, sharper on the right. It still means something is loose -- either the lens or the whole standard. Wait a minute -- it could also be the shutter not mounted flat to the standard. That nothing is really sharp is probably because the focus is off or the lens is not colimated.
 
I just checked how little movement there is from infinity to 20m (60 feet or so). I can move the lens + front standard same amount. The front standard it self is not very loose but in combination with the lens + shutter movement it can move 1mm which correspond to the movement from infinity to 20m......more or less.....

So do you know somebody which can do this kind of repair? .....I probably have to ship it far away from where I live......
 
I have not read all the comments through. I just want to tell that it is a likely story as my Bessa RF which recently I adjusted. My Bessa RF produced the same unsharp images and I checked it and found that the lens was a bit near to the film plate. That means if you focus the lens to infinity (the rangefinder looks correct), all the objects in the photo are not sharp (especially for a larger aperture).

Therefore check the lens assembly by looking at the film plate with a ground glass and the rangefinder to verify if the infinity is real infinity. If it is NOT, then adjust the rangefinder to correct it (I have done this). However, if the lens position can be changed a little by adjust some place of gears, that is the best way, but if there is no way to do so, just change the rangefinder as like I did 🙂

The pressing plate problem I have also met. I used sponge underneath the plate and seems it works. I don't know how to do if the front standard is loosing, and I also want to learn that.
 
I am more and more convinced that it is the front standard which is my problem. And also that the lens/shutter can turn around (two arms not locking the lens/shutter 100% into place). This also means that even on a tripod with cable release the shock from the shutter can make movements of the lens. So if the lens turns around a bit the image will be blurred more at the edges that the center? .....it looks like I have blurr from movements at the edges but center is somewhat sharp? ....just a new theory 🙂

In the moment I am in contact with "certo6" .....to hear if he can fix it. He says that it is a bit tricky to bend the two arms in order to have the lens/shutter locked into place.....but that he had done it several times. I won't do this myself.

Until now I have made sharper images whith my folder from 1925....and this is a camera without a pressure plate......
http://www.pbase.com/mxp/voigtlnder_rollfilm_1925
 
MXP said:
I just checked how little movement there is from infinity to 20m (60 feet or so). I can move the lens + front standard same amount. The front standard it self is not very loose but in combination with the lens + shutter movement it can move 1mm which correspond to the movement from infinity to 20m......more or less.....

So do you know somebody which can do this kind of repair? .....I probably have to ship it far away from where I live......
Click to expand...

Pretty much any competent repair person should be able to do it. I know I can.
 
OK!
You also do repairs?
Can see you are from Virginia. Don't know where Certo6 is located.....but if it is in Europe this is closer for me......
 
Now I did the infinity test using a ground glass. It seems spot on.....which I expected but if I play with the front standard the image will be unsharp. So I most conclude that it is worn and needs to be repaired. The lens is probably very good since the camera has taken a lot of pictures.....
I have the box for this camera and some of the original papers...e.g. the receipt. It is dated 1952 and the cost at that time was approx. US $ 100 which included some filters, shade and case. So not a cheap camera. At that time it was probably a month salary for a "normal" person.
 
Certo6 is on East coast of US

Certo6 is on East coast of US

MXP said:
OK!
You also do repairs?
Can see you are from Virginia. Don't know where Certo6 is located.....but if it is in Europe this is closer for me......
Click to expand...

Not in Europe. He's done 3 or 4 jobs for me... bellows, clean and adjust, resilvered mirror for rangefinder on Mamiya 6 Automat, etc.
 
MXP said:
OK!
You also do repairs?
Can see you are from Virginia. Don't know where Certo6 is located.....but if it is in Europe this is closer for me......
Click to expand...

I think Certo6 is in Illinois or Indiana or one of those states (northern midwest USA). He's the most flamboyant, and most highly visible, but he is far from the best. Yes, I do repairs and restorations. (repairs = functionality, restorations = appearance). I speciallize in folders, but can repair a lot of rigid bodied cameras too.

Edit: There are some good guys in Europe too though, and much as I hate to talk myself out of a job, you'd probably be better off seeking someone more local, with postage being what it is.
 
Last edited:
FallisPhoto said:
I think Certo6 is in Illinois or Indiana or one of those states (northern midwest USA). He's the most flamboyant, and most highly visible, but he is far from the best. Yes, I do repairs and restorations. (repairs = functionality, restorations = appearance). I speciallize in folders, but can repair a lot of rigid bodied cameras too.

Edit: There are some good guys in Europe too though, and much as I hate to talk myself out of a job, you'd probably be better off seeking someone more local, with postage being what it is.
Click to expand...

OK!
I will see if I can find something in Europe. Else I may come back to you. It is a possibility to ship to US.
 
You must log in or register to reply here.
Back
Top Bottom