|
Forum: Pentax Medium Format
04-08-2011, 04:49 PM
|
| |
There have been recently quite a few messages asking how did I do the tilt modification on the Pentax 67 55mm/f4 late model lens, after I had it mentioned in at least one of my posts, so I am here to share my successful and unsuccessful stories.
The following URL describes one way to do it, not exactly my originally way (the author did not thoroughly understand me), and by this along it is hard to get the down tilt up to the desired ~1 degree range:
Effeunoequattro - Il Portale Della Fotografia analogica e digitale
However, after seeing his method, I recently re-worked my sample to include his mod, in additional to my original one, which went much deeper into the lens, with much more risks. It is really hard to describe, but maybe one day I should shoot a series of instruction pictures if there are enough interests, taking the risk that I can be unable to put things back one more time or break something. With now two spacers in stead of one inserted into 2 gaps, I am getting about 1.2 degrees overall, which fits my need pretty well.
Nevertheless, I volunteered to mod another copy of the same lens for a forum member, but could not loose the three inner screws no matter how hard I tried, so that I could only complete the easier "outer" mod, as documented in the web link.
Also, remember that, after the mod(s), the lens become a fixed tilt lens for only the vertical shots (unless you need a horizontal swing, and it happens to be along the right direction, i.e., the close subject is on the left side of the frame). It is fine with me, because the purpose is to help the near-far kind of composition and the down tilt is mostly needed shooting vertical. Another problem is, the original lens structure of course was not designed with such gap(s) created in mind, so the aperture ring will become very stiff, and can be adjusted only with little force.
I examined the structure of almost all the other P67 fixed focusing lenses, but found only the 55mm/f4 late has the room for mods like this, looking at the components from the rear.
Need not to say it is not a easy, a readily practical, or a perfect mod of any kind, and anyone trying this takes his/her big risks, even I managed to get one copy working great, selfishly for myself.
Unfortunately, 55mm is no longer a true wide angle on the much smaller 645D sensor (becoming 40mm in 35mm term, using the short side equivalency which makes sense to me as I print 4:5), so that the value of such tilt mod becomes much less significant in the digital age. Needless to say, a shift/tilt P67 to P45 lens adapter is what we are all really waiting for.
|
|
Forum: Pentax Medium Format
02-15-2011, 09:38 PM
|
| |
Gurtch: Warped has answered your questions, and here is a picture of the LightRoom lens correction panel, where you just select the make and the lens from the lists.
|
