
Originally Posted by
hindenhaag
Concerning RD16 there is only one fault with 200mm focal length: there is no 4º set up. It would be 3.75º with 45%.
An overlap of around 30% is very good. Normally we say that 25% is enough. Overlaps >=45% may cause stitching errors, cause the program might generate too many control points. But to get to know, you should make some test shots.
As the upper rotator - M1_L - is concerned, I can not follow your thoughts. Actually you have to calculate the degree of Pitch = how many degrees you move the upper rail up or down and how many rows you have to shoot to get 180º in vertical.
Hi Heinz,
My bad with the 4° figure, thanks for pointing that out. Unfortunately degrees got rounded along with the percentage figures and I forgot to reformat them in Excel to show decimals. The underlying value was ok at 3.75, it just displayed the rounded value 4. BTW Same thing happened with the 8°, should have displayed as 7.50. They're displayed correctly below.
If overlaps >=45% may cause stitching errors, then it appears I'm going to have problems due to the 7.5° limitation with the upper rotator.
Perhaps you could not follow my thoughts on the M1-L upper rotator because of the wrong percent overlap figures that John pointed out. Or maybe it's because I used the number of click stops instead of degrees like I did in the RD-16 figures. I see where you've translated a +45° pitch to 6 clicks of the upper rotator. My thinking is not to use degrees for the upper rotator in my table because it all boils down to using click stops anyway. Yes/No? Better to keep it simple in the field and just put the click stops in the table instead. No math, no mistakes, less work.....
I've updated the overlap figures for the M1 using the formula John offered.
(FOV less pitch degrees) / FOV = % overlap
Is that the formula you would use? If so, and if the new figures look realistic to you, then the overlaps are so confining that I don't think the M1 is going to work for me. First of all, there is no acceptable overlap at all for the 135mm lens. And if I limit the results to only those where the overlap percent falls between 25% and 45% (instead of 25% and 49%) then the 70mm lens is of no use to me to either.
@zoom 24 you would need 3 rows at +45º, 0º, -45º plus Z/N shots. Upper rotator always clicks by 7.5º per steps, so to reach a pitch of +45º, you have to click 6x.
Plus you have to calculate that using longer focal lengths and getting to 8 rows for example, you can reduce the number of shots coming closer to Zenith or Nadir.
But the upper rotator's 7.5º will be ok . I only have to recalculate my NN5 settings with its 2.5º steps for new pitch steps.
I think I understand what you're saying about the number of rows and 180°. Problem is - I'm not interested in 180°. Making mosaics of scenes originally framed with a 24mm or 28mm lens is what I'm after, which would require focal lengths of 35mm and higher. The 24mm and 28mm lenses are in the table simply because I have them, not because I intend to use them for multi-row 180° panos. I do not understand how the upper rotator's 7.5° will be ok given the overlap figures shown in the table.
Perhaps I should reread this thread and look harder at the NN5.
Hope you get your clamp tomorrow.

Originally Posted by
John Houghton
Frank, I checked your calculations for the percentage overlap for 70mm. The horizontal figures are ok, but the vertical ones appear to be wrong. For a pitch increment of 15°, the percentage overlap is (28.84-15)/28.84x100=48%. For a pitch increment of 22.5°, the percentage overlap is (28.84-22.5)/22.84x100=22%.
John
John,
Thank for pointing that out. If one was wrong, then the whole column was wrong. I used a formula I wasn't sure about, yours is much simpler and does seem to make more sense. The updated table using your formulas is shown below. There's quite a difference though, and some limitations I didn't expect. Do these figures look more realistic? For your perusal I also included the complete table for the M1 figures, which includes all the overlap figures I didn't use that were under 25% or over 49%.
Regards,
Frank
Code:
Table for camera mounted in PORTRAIT orientation (overlap figures rounded to the nearest integer.)
RD-16 M1-L Number of Click Stops (@7.5° each)
------------------- ---------------------------------------
24mm 30° 36° 5 6 7
43% 32% 49% 39% 29%
28mm 24° 30° 5 6
48% 35% 43% 31%
35mm 20° 24° 4 5
47% 36% 45% 31%
50mm 15° 18° 20° 3
44% 33% 26% 43%
70mm 10° 12° 2
48% 38% 48% <--Smallest usable overlap ?
135mm 6° 7.50°
41% 26% <--No usable overlap ?
200mm 3.75° 5° 1
45% 27% 27%
7.5° 15.0° 22.5° 30.0° 37.5° 45.0° 52.5°
1 2 3 4 5 6 7 <--click stops
24mm 90% 80% 69% 59% 49% 39% 29%
28mm 89% 77% 66% 54% 43% 31% 20%
35mm 86% 72% 59% 45% 31% 17% 4%
50mm 81% 62% 43% 24% 5% -14% -33%
70mm 74% 48% 22% -4% -30% -56% -82%
135mm 51% 1% -48% -97% -147% -196% -246%
200mm 27% -46% -119% -192% -264% -337% -410%
Basis for the above figures.....
Field Of View for D700 36 x 23.9 sensor
Lens mm
24mm 73.74° 52.94°
28mm 65.47° 46.22°
35mm 54.43° 37.70°
50mm 39.60° 26.88°
70mm 28.84° 19.38°
135mm 15.19° 10.12°
200mm 10.29° 6.84°