back focusing with mamiya 645 super, HELP!

[rhyno0688]

I have ran a few rolls through a mamiya 645 super over the last week and nearly all the images are out of focus. I dont ever remember this camera being the sharpest thing in my arsenal but have gotten good results in the past of mostly landscapes but recently I have moved towards portraits and have noticed the focus is off. Its not an inch or two but seems to be more like a foot off.

Background of the camera: bought used a few years ago from a local guy and have done primarily landscapes, sharp images have been taken by the camera but they where shot at f11-22 and hyperfocused. My dad is the one who bought it knowing i would use it but he has never shot with it (he says he wants too but shoots digital) to my knowledge it has never been dropped or slammed into. I have several other cameras so I don't shoot it much to begin with so this problem is just now apparent.

I have used 2 different backs with different inserts (using 120 film and have tried a 120 magazine and a 220)
I have used a few different lenses with the same results
so if its not the film plane or the lens, that leaves the mirror. That being said I am aware of the mirror rest being plastic and I have check it and there seems to be no cracks or breaks. Is there a way to adjust the bumper and if so which way, (bottom of the mirror towards the lens or move it back to the back.) I love the camera and would really like to utilize it in my portraiture work but it is simply not usable at the moment for that.

Any Suggestions?

here is a photo I took today and you can see the ground behind my friend is sharp but he is just infront of the the focus. Its not jus this image, I have plenty of them.
edit **I focused on his open jacket

 

[MattKing]

More likely it is a problem with how the viewing screen is seated. Any competent technician should be able to solve this.

 

[Jeff L]

Any chance the focusing screen is in upside down?

 

[rhyno0688]

How would I figure that out?

 

[heespharm]

Remove the screen and see which side is frosted... That goes down toward the body of the camera

 

[rhyno0688]

Perfect, I'll look at that in the morning

 

[heespharm]

Video I found on YouTube

http://youtu.be/8SIJ7XP9OKw

 

[rhyno0688]

perfect, I wasn't sure how to take it. My hassy and rb67 are a bit easier! haha

 

[rbultman]

Check the mirror stop. It was broken on my super. The mirror becomes essentially unaligned causing focus to be off. You can check this by placing a ground glass on the film rails, focus an object on the ground glass, then check the focus in the viewfinder. If the image is our of focus, try carefully lifting the mirror bottom very slightly. If the image comes into focus, and there is no obvious issue with the ground glass, the mirror stop is either broken or out of adjustment. Mine was clearly broken. I bought a new (to me) Pro body instead of fixing the Super.

Sent from my Nexus 5 using Tapatalk

 

[MarkF48]

Check the mirror stop. It was broken on my super. The mirror becomes essentially unaligned causing focus to be off.

Sent from my Nexus 5 using Tapatalk

This is rather common. I had posted the picture below on another forum of the mirror stop in a 645 that is not broken.

 

[mdarnton]

Also, notice that the mirror stop is adjustable. That's to fix this exact problem. The constant repeated hammering of the mirror down on the stop can eventually push it downwards somewhat, and the result is inevitably back-focusing. All SLRs are vulnerable to this problem, eventually, which is why there's an adjustment.

 

[rhyno0688]

thanks guys, i have some fiddling to do now

 

[rhyno0688]

This is rather common. I had posted the picture below on another forum of the mirror stop in a 645 that is not broken.

upon further inspection, this piece is broke. Is there a good place to get one of these pieces?

 

[Dennis S]

http://photo.net/medium-format-photography-forum/00aUH5