Modification to add fixed tilt capability to the Pentax SMC 67 55/4 latest version
(not for the faint hearted!)
What you will get with this modification is a Pentax 67 55/4 lens modified in order to have a fixed 0.5-0.8 degress downward tilt. This way when doing near-far shots at maximum DOF you will get accetable CoC from about 1 meter onward (instead of the normal 3 meters).
Of course this lens won't be able to take "normal" shots. You must dedicate it to vertical landscape use only. If you remove the modification afterwards you will recover full functionality.
Disclaimer.Make this modification only if you are in the right mood and you feel like it. It s not difficult but you must be a bit brave to make it.
You will void your warranty by opening your lens.
I assume no liability for any damage. Your are operating at your own risk!
Many thanks to Mr.Lephing Zha for the precious indications ,
help and faith given.
He's made the same modification and his works can be seen on photo.net (including
stunning photos made with this modified lens)
 |
Tools needed :
- Very good screwdriver - Clamps - Order and cleanness - calm |
 |
 |
| The screwdriver is the keypoint. If you work
with the wrong one, you will screw up everything and won't be able to sell
your lens back beacuse of worn-out screws - if not worse!
I used a PH-00 screwdriver. Made in Switzerland, very high-quality. The
tip of the tool is very tough and precise.
|
|
 |
OK, first step.
Remove the screw indicated . Stay calm and put a bit of downward pressure on the screwdriver before turning it. Once the screws are removed tuck them away in a safe place . I put them on a sheet of paper maintaing the matching screw-thread in order not to mix them back when puttingthem back on (this is as I am very fastidious, don't really need to do that) |
 |
Raise the cover gently. be aware that there is an index bracket that is fitted in a slot underneath. Be careful not to bend it. |
 |
 |
 |
The procedure is at a very good point. now we need to remove another index by removing the two indicated screws. They are blocked by a drop of paint. Be calm and decise when unscrewing them. |
 |
Make sure not to let the screws fall into the barrel, you might not be able to recover them!! |
 |
Use light clamps to pick them |
 |
Be careful there are washers underneath. In my case they were glued. Make sure they are tight, if not remove them carefully and tuck them away |
 |
Here is the index to inform the body of the aperture |
 |
Now remove the bayonet. Six screws to remove. |
 |
Stay calm |
 |
Done! |
 |
Tuck it away together with the six screws |
 |
Easy isn't it? |
 |
This little strip of teflon will do the
trick. Scheimpflug rule welcome to the P67 world!!! The thickness is about 1 mm. Do not use too much otherwise the index will hit the slot on the bayonet and auto-indexing won't work properly. This little shim will bring 0.5-0.7 degree of tilt, enough to improve DOF a great deal. |
 |
Here you can see how to fit the strip |
 |
Be careful in choosing which pair of screws putting the teflon shim on. You want to have a fixed downward tilt that works in vertical shots only. Take in account which side you tilt the camera when doing vertical shots on a tripod. |
 |
From this point on, you have to reverse the
procedure seen to get your lens operational again.
Pay attention when introducing the black cover , stick the long index into the slot precisely!!! |
 |
Very important!!!! |
 |
Last fears gone!!!
Enjoy a bit of Scheimpflug rule with your Pentax 67!! The modification is removable any time with no visible sign . Nobody will be able to tell that you did that. |
Roberto Manderioli © 2/2004
