Troy Ammons
Member
- Joined
- Mar 7, 2005
- Messages
- 172
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I have been shooting a 4x5 with a 90 and 150mm lens for a while and found it pretty simple. Never had any real problems as it was a Sinar so set the focus zero the dial set the focus again read the tilt and apply it and refocus. Mostly simple landscapes.
Now I just decided to go for an Cambo 8x10 SC with a G-Claron 240mm lens and it made my tilt life more difficult.
I tried this shot, and I dont know if its even possible with out stopping way way down. Actually after scanning it I thought I might be better off shooting this shot with 4x5 and a shorter lens for more dof.
First off a LF theory question. Lets say I am using no tilt and stop down and attain a dof 10' in front of the focal point and 20 feet behind the focal point.
Now if I tilt the plane of focus to say 30 degrees is there still 10' on top and 20' below dof at the same F-stop ?? This has really got me confused.
Also another one. When I tilt my lens and refocus how do i know where the true focus point is. Since I sold my Sinar I have been using the far near ??? and refocus method. Not exactly hard science and probalby wrong but....
Okay back to my problem shot.
Just to make the explanation simple (I hope) I have a ramp, say about 15 feet wide. The bottom of the ramp is about 15 feet in front of me and the length of the ramp is about 30 feet and its maybe about 15 feet high. At the top of the ramp there is a bird bath about waste high so add another 3 feet to the top. At each side corner at the bottom of the ramp there is a tree. Each tree is maybe 12-15 feet high.
Now of course what i want is everything in focus from my toes to the top of the bird bath, so i would assume that my tilted plane of focus would need to go from just in front of my feet somewhere, through the top of the bird bath.
Now this plane of focus will be above the ramp and a little more flat than the ramp, but I should be able to get the entire ramp in focus by stopping down some since it is fairly close to parallel to the plane of focus ???
Does that sound right ??
I took the shot and it pretty much turned out okay, except for the trees tops on each side at the base of the ramp are blurry.
Originally i thought that at the those corners of the frame i may have just been at the blurry edge of the lens circle, but now after talking with a friend we are thinking the tops of the trees are blurry due to them being out of the area of sharp focus or i guess you could say too far above the tilted plane of focus at F16.
I took the shot at around F16 trying to keep the speed up a little since there was some wind so my question is.....
If I would have stopped down more like to F32 or F45 45 would it have pulled the tops of the trees into focus or is there another tilt method I needed to use. I only used front tilt and some fall for this shot.
I also think now that my tilted plane of focus may have been a bit too vertical, IE instead of being a slightly flatter slope than the ramp, it may have been a bit more steep than the ramp. Guess its time for a tilt calculator.
Here is a link to the photo. Its not really a ramp but you will get the idea. Its a big file full size so....... You can see the tree tops in the corner of the frame I am talking about. The pine needles in the top corners of the frame have sort of a hard OOF appearance if that makes any sense.
Reduced version
http://upload.pbase.com/tammons/image/49186509/large
Full size version
http://upload.pbase.com/tammons/image/49186509/original
Thanks
Now I just decided to go for an Cambo 8x10 SC with a G-Claron 240mm lens and it made my tilt life more difficult.
I tried this shot, and I dont know if its even possible with out stopping way way down. Actually after scanning it I thought I might be better off shooting this shot with 4x5 and a shorter lens for more dof.
First off a LF theory question. Lets say I am using no tilt and stop down and attain a dof 10' in front of the focal point and 20 feet behind the focal point.
Now if I tilt the plane of focus to say 30 degrees is there still 10' on top and 20' below dof at the same F-stop ?? This has really got me confused.
Also another one. When I tilt my lens and refocus how do i know where the true focus point is. Since I sold my Sinar I have been using the far near ??? and refocus method. Not exactly hard science and probalby wrong but....
Okay back to my problem shot.
Just to make the explanation simple (I hope) I have a ramp, say about 15 feet wide. The bottom of the ramp is about 15 feet in front of me and the length of the ramp is about 30 feet and its maybe about 15 feet high. At the top of the ramp there is a bird bath about waste high so add another 3 feet to the top. At each side corner at the bottom of the ramp there is a tree. Each tree is maybe 12-15 feet high.
Now of course what i want is everything in focus from my toes to the top of the bird bath, so i would assume that my tilted plane of focus would need to go from just in front of my feet somewhere, through the top of the bird bath.
Now this plane of focus will be above the ramp and a little more flat than the ramp, but I should be able to get the entire ramp in focus by stopping down some since it is fairly close to parallel to the plane of focus ???
Does that sound right ??
I took the shot and it pretty much turned out okay, except for the trees tops on each side at the base of the ramp are blurry.
Originally i thought that at the those corners of the frame i may have just been at the blurry edge of the lens circle, but now after talking with a friend we are thinking the tops of the trees are blurry due to them being out of the area of sharp focus or i guess you could say too far above the tilted plane of focus at F16.
I took the shot at around F16 trying to keep the speed up a little since there was some wind so my question is.....
If I would have stopped down more like to F32 or F45 45 would it have pulled the tops of the trees into focus or is there another tilt method I needed to use. I only used front tilt and some fall for this shot.
I also think now that my tilted plane of focus may have been a bit too vertical, IE instead of being a slightly flatter slope than the ramp, it may have been a bit more steep than the ramp. Guess its time for a tilt calculator.
Here is a link to the photo. Its not really a ramp but you will get the idea. Its a big file full size so....... You can see the tree tops in the corner of the frame I am talking about. The pine needles in the top corners of the frame have sort of a hard OOF appearance if that makes any sense.
Reduced version
http://upload.pbase.com/tammons/image/49186509/large
Full size version
http://upload.pbase.com/tammons/image/49186509/original
Thanks