MXP
Established
I have two Bessa II's (Heliar and Color Skopar). Both has been adjusted (rangefinder / focus) and pressure plate. Until now I have not been able to take a sharp image.....not even on a tripod. I have more resolution using a 35mm camera. I can do much sharper images with my Bessa I (Vaskar). It seems my Bessa II images has focus behind where I focus so I think it is a film flatness problem and probably also a problem with the front standard which may not be 100% aligned and not 100% stable. Do you out there have similar problems? .....the film advance on the Bessa II is also a bit strange. It does not prevent the film to "pull back" as much as it does on e.g. a Bessa I. Think this could cause a film flatness problem?
kuzano
Veteran
sanmich
Veteran
did you try the "ruler test" to see if the focus is correct?
You can try this at the four points of the frame to figure out if the lens and film plane are parallel.
You can try this at the four points of the frame to figure out if the lens and film plane are parallel.
MXP
Established
I probably need to do some more controlled testing. But I am a bit disappointed with the cameras. It could be interesting to take out the lens and shutter and look down to the film and see how flat it is. To mount the lens on a Linhof Technika plate to test the lens on a Technika is also possible. I know how sharp 6x9 frames can be.......
MXP
Established
To me it seems to be a very weak point. When the shutter releases the "chock" could cause some small movements of the front standard. I don't know why these cameras are so highly regarded. Apart from this I am a big Voigtländer fan
.....the lenses deserves better Vickko
Veteran
Keep in mind that the shutter release may be causing the lens to move at the time of release. Is the shutter release mechanism perfectly smooth? Try it with a cable release.
With good depth of field, the lens is capable of very good photos (at least the one on my Bessa II is). Even with the front standard misaligned, it will function like a view camera with the lens tilted.
But if the lens is jarred, at the moment of shutter trigger, it won't take a sharp photo.
Vick
With good depth of field, the lens is capable of very good photos (at least the one on my Bessa II is). Even with the front standard misaligned, it will function like a view camera with the lens tilted.
But if the lens is jarred, at the moment of shutter trigger, it won't take a sharp photo.
Vick
Vickko
Veteran
Oh, the front standard can be tightened up - a good tech should be able to do it.
Vick
Vick
chippy
foo was here
to state the obvious, something is defnately not right! there should be no comparison between these and 35mm or the Vaskar lens, with Vaskar pics i find the differances are instantly noticable at a glance, terrible in comparison to scopar or heliar.
no doubt you need to do some testing with film (noting your f stop) and rechecking the camera from front to back, rangefinder etc. winding on just before taking a picture helps to keep film flat as well
Windscale
Well-known
To put it very simply, if you cannot get sharp images, then your lenses and RFs are not coupling properly. All you need is to open your aperture widest and take 2 shots, 1 with an object at infinity and 1 at say 15 feet or 5 meters (according to the RF). If both do not turn out sharp, your lens and/or RF will need calibration. Until you have got these pics sharp then your Bessa IIs are properly calibrated. I can tell you that the ColorSkopar and the Heliar are both excellent lenses which can beat many of today's lenses.
MXP
Established
What I like with the Bessa I with Vaskar is that the front standard is locked into position and seems very steady. Also the film advance seems to lock the film so it can't "pull back". On Bessa II the film advance has a strange design where the film can be pulled back.....maybe 1mm or so. So I have a theory that the film will bent and this causes that focus are behind and uneven over the frame. I know the pressure on the film pressure plate is important also.....
MXP
Established
I will do some ground glass testing again.
FallisPhoto
Veteran
If you are getting sharper photos with a Vaskar, something has gone really horribly wrong.
The obvious first thing to check is the lens. Are all the elements clean and clear? While dirt on the front element has only a very negligable effect, it can have a significant effect on the middle or rear elements. Oil (or fingerprints) on any element at all will have a significant efect. Fungus can also have a very bad effect.
Next most obvious thing to check is the rangefinder. Just because it has been adjusted it doesn't mean it was adjusted correctly. It doesn't mean the focus was adjusted correctly either. I'd check it again by backsighting the camera, using an SLR.
Next, tighten up that front standard -- if it is loose.
Next, try retensioning the springs behind the pressure plate.
MXP
Established
Lenses are very clean (like mint condition). How do you righten up the front standard?
I have attached images to illustrate. There is a "full" image (downsized) and then 100% crops (4000 dpi scan) of center which is the sharpest in the image. Then right side of image which is very unsharp. The sign is clearly readable using e.g. a 12MP DSLR or film.
Attachments
MXP
Established
I can add some more comments to the image. It was taken tidpod mounted with a cable release. I think center sharpness is not as sharp as expected.....but if whole image had this sharpness I may have accepted that this was what the lens could deliver. Right side of image is blurred as you can see. Film flatness problem? ......I still don't like the way the film advance has been made on the Bessa II. The pressure plate tension has been adjusted. I am afraid that the springs will break if I try to bend them more.......
FallisPhoto
Veteran
MXP
Established
It is all 105mm lenses. It was well stoped down around aperture 8.
The lens and shutter is not 100% locked. It can move a little bit. When you fold it out two small arms comming from behind are trying to lock the lens and shutter into place. They could do a little better......
MXP
Established
I am "playing" with a film inserted and with the back open to test my main concern......the film advance mechanism. When I turn the advance wheel.....then when I stop....I would expect the advance wheel to lock where it was (maybe by use of some friction somewhere) but it can turn back about 2-3mm. Which means that the film can pull back a bit. Maybe something is worn in the film advance mechanism. It is the same on both my BessaII's. How are yours?
If I was able to take an image while holding on the film advance wheel I would be able to prevent the film to "pull back".
If I was able to take an image while holding on the film advance wheel I would be able to prevent the film to "pull back".
chippy
foo was here
struts; the bessa II cant use the same struts as the bessa I because the whole lens unit is moved to focus on the bessa II, whilst the bessa I turns the front cell to focus. the strut system on the bessa I is good, its more modern as well. the strut system on the bessa II, if unworn or undamaged should present no problems though and locks in place quite well. you may be able to wiggle or move it a fraction by grabbing the lens with your hand and wiggling, but like the doctor said to the guy that complained that his arm hurt every time he did 'this', the doctor said 'well dont do that then!"
All things being equal (not too worn) out of the two systems the Bessa II that moves the whole lens to focus gives better results. possibly you could show a picture of the camera and its struts? there are a few tell tale signs that show possible problems..
winding knobs: somehow, i dont think this is your problem.
the actual knob on top the bessa II does have a bit of play in it, although all this movement does not transfer to the wind shaft, and film spool. the bessa 1's knob has less wiggle as you have said. ...but, this makes little difference in the end because the spools themselves have much more wiggle, and can move backwards easily a few mm, i find the modern plastic spools sometimes dont fit as tight as some older metal spools so if you wanted to ensure no movement (or less movement) you could try these in the take up chamber, or use a piece of foam or material to make a tighter fit i suppose. at any rate with all this wiggle in the spools i have not noticed a problem...it is simply a matter of winding on just prior to taking a shot, the pressure plate keeps the film flat. it may be worth checking the springs in the take up chamber that grip the film and in general keep or hold the film in place or rolling backward or unwinding.
you would have to have a significant amount of film bellowing (not flat) to cause unsharp pictures at f8 across the whole frame.
its difficult to give a difinitive answer to what is causing the problem without knowing (and seeing) every thing that has been done to the camera and lens. it may be a series of small errors made while putting it back together and adjusting (did you do this yourself?). e.g. have the lens been replaced correctly (or original matched sets), shims for shutter etc, any damage to front standard or struts, rangefinder adjusted correctly, pressure plate as it should be...then, only because the question has to asked, is if you are veiwing only after scanning and if scanner is focused correctly, or there if there is film curl while scanning...i have only scanned minimal pictures but this is area i need to fine tune as nothing i scan seems to come out as sharp as the actual negatives or wet prints i make
i cant see the pics very well on my laptop screen (my PC in for repair--urrg!) but if i had to say, i would say the lens simply arnt colminated properly
All things being equal (not too worn) out of the two systems the Bessa II that moves the whole lens to focus gives better results. possibly you could show a picture of the camera and its struts? there are a few tell tale signs that show possible problems..
winding knobs: somehow, i dont think this is your problem.
the actual knob on top the bessa II does have a bit of play in it, although all this movement does not transfer to the wind shaft, and film spool. the bessa 1's knob has less wiggle as you have said. ...but, this makes little difference in the end because the spools themselves have much more wiggle, and can move backwards easily a few mm, i find the modern plastic spools sometimes dont fit as tight as some older metal spools so if you wanted to ensure no movement (or less movement) you could try these in the take up chamber, or use a piece of foam or material to make a tighter fit i suppose. at any rate with all this wiggle in the spools i have not noticed a problem...it is simply a matter of winding on just prior to taking a shot, the pressure plate keeps the film flat. it may be worth checking the springs in the take up chamber that grip the film and in general keep or hold the film in place or rolling backward or unwinding.
you would have to have a significant amount of film bellowing (not flat) to cause unsharp pictures at f8 across the whole frame.
its difficult to give a difinitive answer to what is causing the problem without knowing (and seeing) every thing that has been done to the camera and lens. it may be a series of small errors made while putting it back together and adjusting (did you do this yourself?). e.g. have the lens been replaced correctly (or original matched sets), shims for shutter etc, any damage to front standard or struts, rangefinder adjusted correctly, pressure plate as it should be...then, only because the question has to asked, is if you are veiwing only after scanning and if scanner is focused correctly, or there if there is film curl while scanning...i have only scanned minimal pictures but this is area i need to fine tune as nothing i scan seems to come out as sharp as the actual negatives or wet prints i make
i cant see the pics very well on my laptop screen (my PC in for repair--urrg!) but if i had to say, i would say the lens simply arnt colminated properly
FallisPhoto
Veteran
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.
sevo
Fokutorendaburando
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