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Bad focus with CFV back
- Thread starter henkan
- Start date
Tinker
Member
Hi,
thanks for posting this; I just got my new CFV50 and have exactly the same feeling; hope that someone can shine some light on this!
regards,
Erik
wbulte
Active Member
There are quite some well-used/abused bodies out there that are out of tolerance relative to the factory standards. We are talking about tolerances in the 1/100 mm range here. Drop a body and chances are it is already out of spec. It is by no-means always visible from the outside if a body has experienced something like this (I once owned a 500C/M that proved to be out of spec due to a physical impact; it was realigned by a factory-trained repair technician to be as good as new.)
The only proper way to check is using the factory-supplied test and alignment riggs. Digital appears to be less forgiving in this area than film. You will need to go find a well-qualified repair person / facility.
Wilko
The only proper way to check is using the factory-supplied test and alignment riggs. Digital appears to be less forgiving in this area than film. You will need to go find a well-qualified repair person / facility.
Wilko
Tinker
Member
Hi Wilko,
I've got a 503CW looking almost as new, but you're right, you won't spot a difference of a few hundreds of a mm. I will take your advise and have the body serviced. In the mean time I will see if I can borrow someone's 500 serie to see if I get the same results.
Thanks,
Erik
jotloob
Well-Known Member
As there are so many HASSELBLAD V-SYSTEM cameras
available "in the field" , it should be quite easy to eleminate the body as a culprit of unsharp RAW images , when properly focused .
I do not believe that a 503CW body , when treated carefully , will be a cause of the above described issue . It is more likely that the sum of tolerances causes the sensor to be too near or too far away from the back of your camera body . We are talking here about may be 0.1mm or even less.
With none of my five bodies + CFV-39 I experience the described issue .
Jürgen
available "in the field" , it should be quite easy to eleminate the body as a culprit of unsharp RAW images , when properly focused .
I do not believe that a 503CW body , when treated carefully , will be a cause of the above described issue . It is more likely that the sum of tolerances causes the sensor to be too near or too far away from the back of your camera body . We are talking here about may be 0.1mm or even less.
With none of my five bodies + CFV-39 I experience the described issue .
Jürgen
wbulte
Active Member
0.1mm is a *lot* ! Obviously the sensor needs to be in correct alignment just as well.
Don't compare your top of the line and tenderly-cared for bodies to the generic stock of 2nd hand HB stuff out there!
Wilko
DDudenbostel
Member
focus problems
I purchased a new CFV39 back in january of this year. I have three bodies, a 500c/m, 501cm and a 500 EL/M. I've used these cameras for years with film in my work and never noticed a problem but when I tested the new back on my 501cm I found the focus to be off. I then tested it on my other bodies and found it to work properly. I shipped the body off for repair and the verdict was the focusing screen was too high and a little adjustment by the tech resolved the problem. Now the images are dead sharp with all three bodies.
Tolerances seem to be more critical with digital. Looking at images at 100% shows every flaw in the lenses and even the slightest missed focus.
I purchased a new CFV39 back in january of this year. I have three bodies, a 500c/m, 501cm and a 500 EL/M. I've used these cameras for years with film in my work and never noticed a problem but when I tested the new back on my 501cm I found the focus to be off. I then tested it on my other bodies and found it to work properly. I shipped the body off for repair and the verdict was the focusing screen was too high and a little adjustment by the tech resolved the problem. Now the images are dead sharp with all three bodies.
Tolerances seem to be more critical with digital. Looking at images at 100% shows every flaw in the lenses and even the slightest missed focus.
nathantw666
Member
I'm a little late to this party, but when I had a digital back for my 553ELX and 500 c/m I found that it was pretty hard to focus the lens. I would focus thinking the picture was okay only to find that I focused incorrectly. I then had to consciously think of what was more important to focus on and carefully focus on that, using depth of field to make up for the rest of the picture. It's possible that you might be running into the same problem I experienced.
I uploaded some photos I took with the digital back onto Flickr. I found that the 60mm wasn't wide enough for me as you can tell with some of the photos since parts of the cars or planes were cut off. http://www.flickr.com/photos/nathantw/sets/72157619526700000/
I uploaded some photos I took with the digital back onto Flickr. I found that the 60mm wasn't wide enough for me as you can tell with some of the photos since parts of the cars or planes were cut off. http://www.flickr.com/photos/nathantw/sets/72157619526700000/
I had the same problem with my Hasselblad once with film. It was caused by aging foam that's on the backside of the mirror to dampen the mirror on return. I was geting back focus o my images. It especially showed up with long lenses at wide apertures.
When it goes (with age) the mirror sits in the wrong place and causes you to focus incorrectly. Service by Hasselblad fixed the problem but I had called someone at Hasselblad service about the issue months before and they had me thinking I was crazy. It was only months later with a second call to Hasselblad repair that someone savvy knew exactly what the problem probably was.
Try setting the lens to infinity and shooting a landscape from a tripod to check alignment. You can also shoot a ruler at a 45 degree angle to see if you're focused where you think you are.
Rich Quindry
Richard Quindry Photography
When it goes (with age) the mirror sits in the wrong place and causes you to focus incorrectly. Service by Hasselblad fixed the problem but I had called someone at Hasselblad service about the issue months before and they had me thinking I was crazy. It was only months later with a second call to Hasselblad repair that someone savvy knew exactly what the problem probably was.
Try setting the lens to infinity and shooting a landscape from a tripod to check alignment. You can also shoot a ruler at a 45 degree angle to see if you're focused where you think you are.
Rich Quindry
Richard Quindry Photography
Tinker
Member
Thanks for these suggestions Rich; especially the one with the rules sounds interesting; will give it a try this weekend!
Regards,
Erik
wbulte
Active Member
Please note that the 'mirror foam' issue is only applicable to older style bodies.
The newer bodies with the bigger Gliding Mirror System (I hope I correctly remember the marketing name) do not use foam mounts, so there is no foam to deteriorate to start with.
500C/M for example uses a foam mounted mirror, a 501C/M does not.
hth
Wilko
The newer bodies with the bigger Gliding Mirror System (I hope I correctly remember the marketing name) do not use foam mounts, so there is no foam to deteriorate to start with.
500C/M for example uses a foam mounted mirror, a 501C/M does not.
hth
Wilko
I'm really late to this thread however, I just purchased a Phase One P30 back for my 501cm. I have noticed problems with focus however mostly they seem to be related to camera vibration. After two weeks with the DB virtually none of my handheld shots are usable (even at 1/500 sec) due to focus. My tripod shots are almost all perfectly sharp and even better when using mirror lockup.
With film I could handhold down to 1/60sec and still get usable prints but with the DB and ability to zoom to +300% in Capture One, movement really shows up.
My 501 body is less than one year old (new old stock from dealer) and I'm the only owner/user so I don't think it's a body problem.
With film I could handhold down to 1/60sec and still get usable prints but with the DB and ability to zoom to +300% in Capture One, movement really shows up.
My 501 body is less than one year old (new old stock from dealer) and I'm the only owner/user so I don't think it's a body problem.
nathantw666
Member
Truthfully, if you're printing to huge sizes, then looking at your pictures at 300% or even 200% should be necessary. However, if you're printing your photos at normal sizes, the "blurred" areas in your pictures won't even show up.
When I started with my Hasselblad in 1994 all my photos were out of focus and were filled with mirror induced shake. It just takes some practice and time to learn to rid yourself of it.
If you go to my Flickr photo stream (http://www.flickr.com/photos/nathantw/sets/72157619526700000/) you'll see a bunch of relatively sharp photos. They were taken with a handheld Hasselblad 553elx with a 60mm lens (comes out to 80mm after sensor magnification) on a relatively cloudy day. The ISO was 100 since I couldn't or wouldn't change it on the Kodak DCS Pro Back Plus. What you don't see is that some of the pictures are like yours, blurry if you increase the magnification by a lot.
If the pictures look fine without the scrutiny of heavy magnication then I think you're fine. The problem is that everyone is so used to ultra-sharp pictures from the variable ISO's of today's digital SLR's that they forget that a slightly blurry or camera shaken/mirror induced shake is okay. I used to be a stickler for "everything must be perfect" technique and if it was just not up to my standards then it was a throw away. After a while I ended up just throwing up my hands and saying "this is what I have and if you don't like it then oh well." You know what I found out? That life goes on and everything is cool and people still love the photos I take. I've gone back to slides I've taken years ago, ones I had forgotten because they were "throw aways" and found they were damn good. I seem to appreciate them more now. You may find the same.
When I started with my Hasselblad in 1994 all my photos were out of focus and were filled with mirror induced shake. It just takes some practice and time to learn to rid yourself of it.
If you go to my Flickr photo stream (http://www.flickr.com/photos/nathantw/sets/72157619526700000/) you'll see a bunch of relatively sharp photos. They were taken with a handheld Hasselblad 553elx with a 60mm lens (comes out to 80mm after sensor magnification) on a relatively cloudy day. The ISO was 100 since I couldn't or wouldn't change it on the Kodak DCS Pro Back Plus. What you don't see is that some of the pictures are like yours, blurry if you increase the magnification by a lot.
If the pictures look fine without the scrutiny of heavy magnication then I think you're fine. The problem is that everyone is so used to ultra-sharp pictures from the variable ISO's of today's digital SLR's that they forget that a slightly blurry or camera shaken/mirror induced shake is okay. I used to be a stickler for "everything must be perfect" technique and if it was just not up to my standards then it was a throw away. After a while I ended up just throwing up my hands and saying "this is what I have and if you don't like it then oh well." You know what I found out? That life goes on and everything is cool and people still love the photos I take. I've gone back to slides I've taken years ago, ones I had forgotten because they were "throw aways" and found they were damn good. I seem to appreciate them more now. You may find the same.
Albion.Bowers
New Member
Bad focus with CFV back...
It is also possible that certain lenses will require much more critical care with focus than others. Wide angles (normally more tolerant of depth of field focus errors) will require extra care to be well focused (wide angles, having shorter focal lengths, will be more sensitive to slight misalignment of the focal screen). And telephotos (usually less tolerant of depth of field focus errors) will be less susceptible to focal screen misalignment...
It is also possible that certain lenses will require much more critical care with focus than others. Wide angles (normally more tolerant of depth of field focus errors) will require extra care to be well focused (wide angles, having shorter focal lengths, will be more sensitive to slight misalignment of the focal screen). And telephotos (usually less tolerant of depth of field focus errors) will be less susceptible to focal screen misalignment...
Thank you Nathan and Albion,
Unfortunately often it's not a blurred area but the whole image. It has surprised me that my 250mm Sonnar extremely sharp (when on a tripod), I expected it to be the least sharp lens. All of them are very good (Zeiss, what would I expect) but I had expected the 250 to be the most difficult and the 50 Distagon would be the most forgiving, this has not been the case.
Unfortunately often it's not a blurred area but the whole image. It has surprised me that my 250mm Sonnar extremely sharp (when on a tripod), I expected it to be the least sharp lens. All of them are very good (Zeiss, what would I expect) but I had expected the 250 to be the most difficult and the 50 Distagon would be the most forgiving, this has not been the case.
nathantw666
Member
I don't know if this will help you, but I use a split prism rangefinder on my focusing screen. I also use the magnifier on the waist level or my pme-45.
blowupster
Member
Well these days I use the 100mm/3.5 that is clearly the sharper lens. Foccusing is really hard as there are allmost no mistake allowed. I took portrait at 10m at 5.6 and then noticed that hears and eyes are not correctly focussed at the same time if I use 100% view for my screen. To me it seams impossible to turn the focussing ring to be more precis for these distances.
Last Saturday I spent time in a forest with a tripod and used F 11 to get sharpest pictures: ok better but impossible to get enouth deep of field for my pictures.
Worse lenses allow to get more homogen pictures. I'm realy thinking to put a video sensor in the center of the camera sceen to get a hand made liveview to help focussing. A a split prism rangefinder does not help so much you need to be more precise and for portrait, the focusing spot is not in the center.
Last Saturday I spent time in a forest with a tripod and used F 11 to get sharpest pictures: ok better but impossible to get enouth deep of field for my pictures.
Worse lenses allow to get more homogen pictures. I'm realy thinking to put a video sensor in the center of the camera sceen to get a hand made liveview to help focussing. A a split prism rangefinder does not help so much you need to be more precise and for portrait, the focusing spot is not in the center.
nathantw666
Member
You need to remember that with the increasing focal length your depth of field will be less. For example, even though the 60mm lens is a wide angle lens for medium format it's still a 60mm lens. If you take you 35mm camera or DSLR and put a 50mm or set your zoom at 60mm you'll find that depth of field will be similar to that of the 60mm on the medium format. So it's sometimes hard to get near to far sharpness even when stopping down.
nathantw666
Member
I forgot to mention that even on my D700 I can't figure out why some of my handheld shots are blurry when magnified at high levels even though the pictures were taken at 1/1500 or higher! It's the darnest thing.
DDudenbostel
Member
You'll never be satisfied with your results unless you get realistic about them. My CFV39 back at screen resolution and 100% is an image roughly 100 inches across if it were to be printed. Consider we're viewing this at a few inches and can now see issues we would never see in normal printing. How large do we normally print and how close do we view them in real life. Print your images at native size and view them on the wall at normal viewing distance. Unless the images are really a mess you'll never see a little softness.
The same problems existed with our film images but we never examined them at this magnification. Generally I examined my images with a 4 or 5x magnifier. I have recently scanned a large number of my 6x6 Hasselblad images (B&W), 35mm and 4x5. I scan on a Fuji Lanovia Quattro which is about as good as it gets in a professional prepress scanner short of the best drum scanners. I'm scanning to fairly large to extremely large (1.5 gig files) and on 100% examination the images I printed in the darkroom that looked fantastic now look marginal. At proper print size and viewing distance they look fantastic again.
Since getting my CFV39 back I've become a lot more realistic about sharpness. A tiny bit of edge softness at 100% or a little vibration is no big deal because I and my clients never enlarge to 100 inches and view the image at 6 inches.
The same problems existed with our film images but we never examined them at this magnification. Generally I examined my images with a 4 or 5x magnifier. I have recently scanned a large number of my 6x6 Hasselblad images (B&W), 35mm and 4x5. I scan on a Fuji Lanovia Quattro which is about as good as it gets in a professional prepress scanner short of the best drum scanners. I'm scanning to fairly large to extremely large (1.5 gig files) and on 100% examination the images I printed in the darkroom that looked fantastic now look marginal. At proper print size and viewing distance they look fantastic again.
Since getting my CFV39 back I've become a lot more realistic about sharpness. A tiny bit of edge softness at 100% or a little vibration is no big deal because I and my clients never enlarge to 100 inches and view the image at 6 inches.