Nodal point for panos for ZE 50MP and 100MP
/forum/topic/1002615/0

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Rajan Parrikar
Registered: Sep 09, 2006
Total Posts: 1400
Country: United States

Does anyone have the numbers for the nodal point (or the No Parallax Point) for the ZE 50MP and the ZE 100MP lenses with 5DII using the ReallyRightStuff pano package (single row, landscape mode)? I plan to do the measurement one of these days and want to compare notes.



Mike K
Registered: Mar 01, 2002
Total Posts: 2252
Country: United States

The choice of L bracket also is very critical in defining your setback distance for nodal point. I have an older RRS pano package and not quite as old 5DII bracket, and measuring from the center of the clamp the nodal rail for the Zeiss 50/2 MP is 117mm for both landscape and portrait orientation (some L brackets are quite different with orientation). This is a relatively short distance, as 0mm is the entire length of the rail and 180mm is near the back edge of the camera body.

In absolute measurement, I am not confident that this setback distance of my equipment can accurately compare to your set up. Unfortunately, for relative comparison I do not own the 100/2 MP, wish I did!
Mike K



Rajan Parrikar
Registered: Sep 09, 2006
Total Posts: 1400
Country: United States

Thank you, Mike. I have the RRS L-bracket for 5DII. I'll note down your values for the setback.



LightShow
Registered: Aug 03, 2009
Total Posts: 5147
Country: Canada

I think getting the measurement from the EF mount will be of more use to anyone that is looking for this information. Just saying...



carstenw
Registered: Dec 26, 2005
Total Posts: 15973
Country: Germany

I have been using 110mm for the 100/2, but this is on a D3, so some adjustment may be necessary? This is the reading directly from the rail.



Ardea
Registered: Oct 19, 2002
Total Posts: 272
Country: United States

5D MkII RRS L plate RRS Pano setup ZE 100MM/2. 10.25mm setting on slide fore zero parallax.

Richard



Rajan Parrikar
Registered: Sep 09, 2006
Total Posts: 1400
Country: United States

Thank you, Richard. Now I have the values for both lenses to compare to.



HerbChong
Registered: Dec 02, 2005
Total Posts: 7276
Country: United States

waste of time for landscape work. not enough DOF to have anything close enough to matter.

Herb...



Ardea
Registered: Oct 19, 2002
Total Posts: 272
Country: United States

Hi Herb,

Not true. May I suggest you try focus stacking using Zerene Stacker. That solves the shrter apparent DOF with longer lenses.

Richard



HerbChong
Registered: Dec 02, 2005
Total Posts: 7276
Country: United States

sorry, i know well about and do focus stacking and it is still a waste of time on landscape panoramas.

Herb...



carstenw
Registered: Dec 26, 2005
Total Posts: 15973
Country: Germany

I think you are assuming that everyone wants to do the kind of landscape photography you want to do. This is, however, not the case.



RustyBug
Registered: Feb 02, 2009
Total Posts: 13411
Country: United States

Trying to learn about this topic ... is it such that Herb is referring to landscape without any foreground elements that would be candidates for parallax, such that by the time you reach those distances, any parallax is undetectable without a foreground reference ... like how the viewfinder in a rangefinder is 'off' for closer work, but 'fine' for longer work ??



HerbChong
Registered: Dec 02, 2005
Total Posts: 7276
Country: United States

you don't use a 50mm lens for that kind of landscape photography. i stitch 21mm shots with visible objects close enough to touch from my tripod position without a nodal slide and without parallax error being visible. i also use a 50mm ZF for multirow landscape photography. anything that includes infinity doesn't have enough DOF for any object that might show parallax error to be in focus enough to tell that there is parallax error. do enough focus stacking to get to a distance where it will matter and you will have two problems, far too many images, and magnification errors since you are refocusing so that the whole thing won't stitch without massive halos.

Herb...

carstenw wrote:
I think you are assuming that everyone wants to do the kind of landscape photography you want to do. This is, however, not the case.



carstenw
Registered: Dec 26, 2005
Total Posts: 15973
Country: Germany

HerbChong wrote:
you don't use a 50mm lens for that kind of landscape photography.

carstenw wrote:
I think you are assuming that everyone wants to do the kind of landscape photography you want to do. This is, however, not the case.



Okay, so far you have told us how we should use DoF, how we should not focus stack, and now you are telling us what to use 50mm lenses for. Why don't you just write the rest of your "rules" right now that anyone may choose to ignore them as they wish. Rigid rules rarely improve photography for anyone but beginners.



HerbChong
Registered: Dec 02, 2005
Total Posts: 7276
Country: United States

doing things that are a waste of time doesn't benefit anyone except the equipment sellers. there are times when a nodal slide make a difference and there are times when it doesn't. 13 years of shooting digitally stitched panoramas told me what is needed and what isn't. for landscape work, even when you can touch the closest subject, nodal slides are wasted. indoor architectural work and macro panoramas where lens clearance of the subject is an issue are two examples where it does matter. i've owned two Kaidan full multirow panorama heads and now have the RRS ultimate after discarding a few others along the way along with a couple of dozen software packages too. do enough panorama shooting and you will know those rules called optics and can't be ignored.

Herb...



Ardea
Registered: Oct 19, 2002
Total Posts: 272
Country: United States

Well, damn I guess I have to sell all my gear. It appears Herb really fits into the catagory of "... are like opinions, everyone has one". IMHO

regards Richard





RustyBug
Registered: Feb 02, 2009
Total Posts: 13411
Country: United States

Taking the 'half-full' perspective ... I think Herb is just trying to save fellow members a few of their $$$ if he can, even if it comes across as a bit 'over-zealous' at times and may not be applicable for everyone.

Been there, done that ... I'm pretty sure Herb & I are the only two on FM to ever do so.

However, as a newbie to the stitching game ... should I be reading this as "focus stacking" is an alternative method to contending with parallax, whereas nodal points are a preventive method for reducing parallax ... did I read that right ??



carstenw
Registered: Dec 26, 2005
Total Posts: 15973
Country: Germany

HerbChong wrote:i've owned two Kaidan full multirow panorama heads and now have the RRS ultimate after discarding a few others along the way along with a couple of dozen software packages too. do enough panorama shooting and you will know those rules called optics and can't be ignored.

I also own the RRS panorama kit and have done more than enough panoramas to know that your "rules" are wrong. If you can touch the nearest subject, you will certainly need a panorama head to do a problem-free stitch.

What you desperately "need" to do is forget everything you think you know for two reasons: 1) to become more liberated and creative and not so rule-based, and 2) stop telling everyone what they should and shouldn't do.

--

Rusty, focus stacking is like stitching, but instead of stitching neighbouring shots, you "stitch" (i.e. stack) shots in depth-order. You make many shots focused at different depths and use software like Helicon to create a single shot, sharp in the entire region of interest. This can be useful in situations where you cannot get enough depth of field, for example with a close foreground object of interest and a distant background, both of which must be critically sharp for a large print. It also becomes more relevant with larger (read: medium (and large) format) sensors, where less depth of field combines with larger resolution to make the whole thing more critical.

Also, it isn't actually the nodal point you want, but the entrance pupil. This is the apparent location of the aperture when viewed from the front of the lens (although there is also a more accurate optical way to find it, of course), and if you rotate the lens around this point, then you will be able to stitch perfectly (after correcting vignetting and distortion, e.g. barrel distortion) without foreground/background objects changing their relationship to each other in neighbouring shots, necessitating a lot of tedious clean-up work to make a panorama work. It is normally only necessary to use a panorama head when you start including close objects in your composition, as the relative position of distant objects barely changes when you rotate the lens/camera for neighbouring shots.

[Edit: Aham jumped in before I finished my edit: his is the short summary, same thing.]



AhamB
Registered: Jul 11, 2008
Total Posts: 5082
Country: United States

Rotating around the nodal point eliminates parallax. Focus stacking is used simply to increase DOF (usually for macro). Some info on focus stacking: http://www.macrostop.com/



RustyBug
Registered: Feb 02, 2009
Total Posts: 13411
Country: United States

Thanks guys,

I'm thinking about using some 100mm glass to cover an otherwise 20mm-28mm FOV (ff) at a distances of about 15-30 feet with a DOF of about 12-15 feet (rough estimates). I'm assuming I'll incur parallax in the process, and as such need to learn how to determine nodal points and get as level as possible through the arc.



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