Blurred edges in 'good' panoramas

[Richard]

I'm using a Sigma 8mm 3.5 with a Canon Rebel XS & PTGui 8.1.4. I
usually shoot 8 around at 5-degrees up. Sometimes I'll use all 8
shots, sometimes 6 etc. But what I'm finding on EVERY panorama I shoot
is that I'm getting a soft seam when stitching.

The image gets gradually more blurry left-to-right, then suddenly
there's a hard edge when the next shot kicks in.

Here's an example cut from a panorama:
http://www.multimediaaction.com/test/edge.jpg

And here's a straight single shot with the Sigma. So I think the lens
is ok and sharp enough ? Or not?
http://www.multimediaaction.com/test/IMG_1777.JPG

I've been careful with the panorama head calibration, usually get a
'good' result when optimizing, and have tried all sorts of settings
with focus, f-stop, metering etc. Nothing seems to make any
difference. By adding or subtracting shots, or changing the blend
priority I can 'move' the blurry edge to a different part of the
panorama, but I can't get rid of them !

It's driving me absolutely nuts !

Does anyone have any clues about what I'm doing wrong ?

[PTGui Support]

Hi Richard,

My only explanation would be that the blurryness is really there in the
edges of your source images.

Your test shot actually is very unsharp near the edge, but that could be
because the lens was focused on the strawberries. Have you looked at
your source images at 100% size?

Joost

[Roger D. Williams]

I used to see this sometimes, fortunately rarely, and in my case I
became reasonably sure that the blurring was caused by blending
at or rather near the seam. When the two images being blended are
nearly but not QUITE coincident (I noticed it particularly with
grass that was being rippled by a breeze) then PTgui does a blend
that appears to use BOTH images (perhaps 50% each?). I found that
I could get rid of this by outputting layered images PLUS the
blended panorama and painting through the blended image to reveal
the layer(s) beneath it. If this brushes away the blur, then you
are experiencing the same trouble I had. Since you say you can
move the border around, I would guess this is what is happening,
and you are revealing one or other of the two underlying layers
and therefore eliminating the blur that comes from blending
them. I hope this is clear...

The only suggestion I can offer is that you very carefully
optimize a panorama of something like a brick wall, and continue
until you get not just "good" but within, say 1 pixel average
and no more than 2 or 3 pixels max. Then save your lens settings
to the lens database and read those settings into PTgui for all
subsequent panoramas with that lens. You will have to use the
"Advanced" option (which you probably should do anyway, if you
aren't already).

"Good" can still have maximum control-point discrepancies of 10
or 15 pixels, quite enough to blur the edges of blades of
grass or leaves on trees, etc.

Of course if the grass (or leaves, or whatever) are actually
waving in the wind, then you may only be able to shift the blur
to a less obvious position. I don't see why the edge of the blur
is so clear cut, though. Perhaps your problem is due to a quite
different effect?

Roger W.

PS I use the same lens, and would say that it is plenty sharp!

PPS You are shooting more shots than needed for 360 coverage
with good overlap--four is plenty, I never use more--and it
might be worth checking that you have control points ONLY
between adjacent images. In my experience, control points
between non-adjacent images, even if unambiguously placed on
clearly recognizable features of both images, can screw up
the stitching. The control point table will show you which
control points link which images, and I would delete the
ones that link, say, image 0 with image 2, leaving those
between 0 and 1 and between 1 and 2, etc.

On Tue, 21 Apr 2009 15:31:57 +0900, Richard <richa...@internode.on.net>
wrote:

--
Work: www.adex-japan.com
Play: www.usefilm.com/member/roger

[PTGui Support]

Hi Roger,

Indeed, small misalignments can cause blur as too, but the blurryness
would be limited to a small band (the blender uses a small transition
band for high frequency content). This doesn't seem to be the case in
Richard's example.

Joost

[Roger D. Williams]

On Tue, 21 Apr 2009 17:40:19 +0900, PTGui Support <sup...@ptgui.com>
wrote:

>
> Hi Roger,
>
> Indeed, small misalignments can cause blur as too, but the blurryness
> would be limited to a small band (the blender uses a small transition
> band for high frequency content). This doesn't seem to be the case in
> Richard's example.

Hmmm. In that case I am probably experiencing the same problem as Richard,
without knowing it, because the blurring I experienced was not confined to
such a narrow area. I remember painting large areas of the bottom of
several panoramas. Come to think of it, one of them had a gravel base,
so there was no wind ripple!

What else could it be?

Roger W.

[Joergen Geerds]

without seeing the source file, but it looks to me as if you had
autofocus on, or had a bad case of motion blur in one of the frames,
maybe you bumped the tripod during the shot?

just some ideas.

joergen

On Apr 21, 2:31 am, Richard <richardp...@internode.on.net> wrote:
> I'm using a Sigma 8mm 3.5 with a Canon Rebel XS & PTGui 8.1.4. I
> usually shoot 8 around at 5-degrees up. Sometimes I'll use all 8
> shots, sometimes 6 etc. But what I'm finding on EVERY panorama I shoot
> is that I'm getting a soft seam when stitching.
>
> The image gets gradually more blurry left-to-right, then suddenly
> there's a hard edge when the next shot kicks in.
>
> Here's an example cut from a panorama:http://www.multimediaaction.com/test/edge.jpg
>
> And here's a straight single shot with the Sigma. So I think the lens

> is ok and sharp enough ? Or not?http://www.multimediaaction.com/test/IMG_1777.JPG

[Richard]

Roger and Joost, thanks for the ideas and detailed comments :-)

I've gone back and reloaded all my old panoramas one by one previewing
and exporting and looking at the seams, as well as he original images.

I think I'm seeing two things: blurred edges caused by stitching
images with chromatic aberations, and perhaps more importantly, all my
images seem to be very soft on the bottom edge of the lens. Shooting
in the panosaurus this translates to soft right-side edges.

Funnily enough I did one shoot where I accidently left the extra Sigma
lens ring on. That's the ONLY shoot where I'm not seeing these blurry
seams. I'm going to shoot another now where I have the lens ring on
and off and compare. I'll report back.

But I didn't think that having a slightly blurry edge would matter
that much when I shoot eight-around. I shoot eight-around because I
thought that the stitcher would then just take the well-focused center
area of each image and ignore the distorted edges. But since I'm
getting blurry seams then perhaps that's not how it works ?

best regards,
Richard

[michael crane]

2009/4/21 Richard <richa...@internode.on.net>:

Can you borrow another camera from somewhere ?
So you can isolate that as a cause ?
regards

mick

[Richard]

I shot an interior four-around 15-degrees up with four-around 15-
degrees down with the Sigma ring on. That didn't quite get the zenith
or nadir, but did give a 1.7 'very good' stitch. No fuzziness to
bother about - some areas are slightly sharper than others, but within
tolerance.

Then I shot a four-around 5-degrees up without the Sigma ring.
And .... same result ! No overt blurriness and better zenith & nadir
cover. A 1.7 'very good' result with no tweaking.

This was at night, in a room with a single incandescent bulb with HDR.
f5.6 manual focus @ 3.

One thing I did do differently to usual was to very accurately space
the shots. Normally I just rotate the camera around to get my eight
shots, not really worrying about whether each shot is too close to 60-
degrees separate. This time I tried to make sure the four shots were
each at 90-degrees. Perhaps that makes a difference too ? (Would love
to try another camera, but none available atm...)

I'll try some more exteriors tomorrow shooting just four-around. But
I'm still bewildered. For a while I was convinced I had a dud lens,
now I'm thinking it's maybe exterior chromatic aberation effects on
stitching and poor angular separation ?

[Roger D. Williams]

On Tue, 21 Apr 2009 22:35:20 +0900, Richard <richa...@internode.on.net>
wrote:

> I'll try some more exteriors tomorrow shooting just four-around. But
> I'm still bewildered. For a while I was convinced I had a dud lens,
> now I'm thinking it's maybe exterior chromatic aberation effects on
> stitching and poor angular separation ?

Chromatic aberration is a killer. Any feature ocurring on the left of
one image and the right of the next will have its coloured fringes
on the opposite sides! This makes it very difficult to stitch well.

It also makes traceries of leaves and branches against the sky, often
occuring near the zenith, of course (and therefore very near the
edge of the field of view where CA is strongest) look quite fuzzy.
Stitching after having removed CA is FAR superior both in ease and
quality of results. Well worth doing, in other words!

[Richard]

I've just experimented with a few shots and eliminating it does make a
big difference ! A section of grass that I thought was just badly
blurred has suddenly come sharp again :-) Hurrah !

Can you tell me where and how you integrate chromatic aberration
adjustment into your workflow ? And do you apply the same chromatic
adjustments onto bracketed HDR images ? Do all images in a bracket
need the same adjustment, or just when it's visible ?

Hand-crafting each one in Lightroom before importing to PTGui seems a
bit tedious, but if that's what's required...

[John Houghton]

The chromatic aberration was the first thing I commented on over on
the PanoGuide forum. I batch convert all RAW images of a panorama in
Photoshop's ACR using the same chromatic aberration correction
parameters. It works fine for me.

John

[Richard]

Thanks John,
I did follow your other good suggestions about the shot and rotating,
which gave me great relief it wasn't the lens. But I don't normally
shoot RAW and was convinced this was more of a focus issue.

So you just manually correct for one image and then batch everything
to that ?

Thanks again

[John Houghton]

On Apr 21, 5:44 pm, Richard <richardp...@internode.on.net> wrote:
> So you just manually correct for one image and then batch everything
> to that ?

Yes!

John

[Joergen Geerds]

CA is a fixed thing for every lens... once you have figured out how
much CA correction you need (looking at a corner of your source RAW at
200%), it is easy to apply that setting in LR to all your RAW files
(you shoot RAW, don't you?).

joergen

[Richard]

I've learned a hell of a lot from this thread. Thanks very much :-)

[HansNyberg]

On Apr 21, 2:37 pm, michael crane <mick.cr...@gmail.com> wrote:
> 2009/4/21 Richard <richardp...@internode.on.net>:

>
> Can you borrow another camera from somewhere ?
> So you can isolate that as a cause ?
> regards

If there is a difference in focus side to side there may very well be
a camera sensor miss alignment.
See this article
http://diglloyd.com/diglloyd/free/Misalignment/index.html

Hans

[ala...@blueyonder.co.uk]

Hi Hans,

I have read your email to the fpp list regarding cube faces and how to
produce them using PTGUI, thanks you very much for that.

In your opinion which is the best size for a Maximum size ("no loss of
detail")panorama of say 11000 x 5500 and what % quality will you use?

kind regards,

Rodrigo

[Peter Nyfeler]

Hi Richard

Richard schrieb:

> I'm using a Sigma 8mm 3.5 with a Canon Rebel XS & PTGui 8.1.4. I
> usually shoot 8 around at 5-degrees up.
>

...just an idea...

Aren't 8 shots with a Sigma 8mm overkill in therms of overlaping?
Probably some pictures arent used for the final panorama and/or
the seam badly positioned. The NPP is also varying with different
pan angles.

Bes regards

Peter

[Erik Krause]

Joergen Geerds wrote:

> CA is a fixed thing for every lens...

To be correct only transverse CA (TCA) is fixed, longitudinal CA is
reduced by stopping down.

TCA will most likely vary with focal length of a zoom lens. And it might
change with focusing distance even for prime lenses. More information on
http://wiki.panotools.org/TCA

--
Erik Krause
http://www.erik-krause.de

[michel thoby]

Le 22 avr. 09 à 22:55, Erik Krause a écrit :

And in addition, fisheye lenses TCA varies with the light wavelength
(e.g. incandescent / sunlight / fluorescent / etc.):
http://tinyurl.com/32jjdz
Sorry, unlike all the rest, the Sigma 8 mm f3.5 lens was tested here
under a single lighting.

The blue channel is most affected and especially at or near the edge
of the coverage. In contrast, the red channel seems not to spread too
much from the (reference) green channel.
Hence a generic correction strategy can generally be adopted
satisfactorily. But specific TCA correction settings should be
applied for getting the **best** output... when you look at a corner

of your source RAW at

200% (as Joergen has suggested;-)

Regards,

Michel Thoby

[Erik Krause]

michel thoby wrote:

> And in addition, fisheye lenses TCA varies with the light wavelength
> (e.g. incandescent / sunlight / fluorescent / etc.):
> http://tinyurl.com/32jjdz

I suspect this is at least partly an effect of longitudinal CA. CA is a
property of all optical media and clearly wavelength dependent. CA is
BTW the reason why there is a rainbow or why a prism generates a spectrum.

Lenses are usually corrected for LCA, but there are different types of
correction and it never is perfect. Depending on how much wavelengths
are corrected there are f.e. achromatic (2 wavelengths), apochromatic
(3) or superachromatic (4) lenses. There are nice diagrams on
http://toothwalker.org/optics/chromatic.html (scroll down to Figure 5 -
"chromatic" means a totally uncorrected lens, like f.e. a loupe)

This shows that an achromatic lens has most LCA (and probably TCA, too)
left in the blue channel. If you compare channels at 200% or higher, the
blue one often is the most blurred one. This is because the correction
curve leaves the zero-line progressively with shorter wavelength.

Now if you have different types of light, they mostly differ in the blue
channel. Incandescent light spectrum blue side ends at longer wavelength
than sun spectrum. Fluorescent light has no contiguous spectrum at all
but consists of several narrow bands. Could well be only one such band
is inside the range of the blue filter. If two bands are inside, they
could well cause what you call ghosts in http://tinyurl.com/2zzjsl

If the shortest wavelengths from the blue channel are missing, it is
pretty clear that both chromatic abberations are smaller, since the lens
might be corrected well for the long wavelength end of the blue channel,
but not for the short wavelength end.

[hamid.m...@gmail.com]

Hi Richard,

I have the exact same problem. I am using a Canon 60D and Sigma 8mm 3.5. 

Did you ever find the reason for the blurriness and could you resolve it.

Best regards,

Hamid

[JPS]

Hi Erik !

Reading your last post, something crossed my mind: would it be better for the overall IQ of the images- to only select the blue channel to correct the CA, and maybe after that, resellect all the channels and give a final correction of the CA, if needed ?

;-)

[Erik Krause]

Am 26.04.2016 um 13:09 schrieb hamid.m...@gmail.com:
> I have the exact same problem. I am using a Canon 60D and Sigma 8mm 3.5.
> Did you ever find the reason for the blurriness and could you resolve it.

You revived a very, very old thread. The examples in the quoted message
are no longer available. If you make your own examples available, may be
we can help.

Please do not add attachments or images to your posts; instead upload
your files at a file sharing site (for example http://sendspace.com// )
and include a link in your message.

[hamid.m...@gmail.com]

On Tuesday, 26 April 2016 19:17:55 UTC+2, Erik Krause wrote:

Am 26.04.2016 um 13:09 schrieb hamid.m...@gmail.com:
> I have the exact same problem. I am using a Canon 60D and Sigma 8mm 3.5.
> Did you ever find the reason for the blurriness and could you resolve it.

You revived a very, very old thread. The examples in the quoted message
are no longer available. If you make your own examples available, may be
we can help.

Hi Erik,

Yes the thread is very old indeed, but I couldn't find another more recent one that fit my issue so precisely.

I have uploaded 3 images that are available here: https://www.sendspace.com/filegroup/7XS3LM37vJ6lrA7poQGPrLokVjIju92H

If one looks at the stitching seams the blur is evident. 

I take 3 brackets that I merge with Photomatix before stitching with PTgui.

Thanks,

Hamid

[John Houghton]

Thank you for uploading those sample panoramas.  The problems at the seams at the nadir are very evident, and the uncorrected chromatic aberration is quite bad.  But we really need to have a sample set of camera images.  I hope that you shoot raw and that you can supply copies of just the 0ev exposure set.  If no raw shots are available, then medium quality jpegs will be fine.

John

[hamid.m...@gmail.com]

On Wednesday, 27 April 2016 12:12:31 UTC+2, John Houghton wrote:

Thank you for uploading those sample panoramas.  The problems at the seams at the nadir are very evident, and the uncorrected chromatic aberration is quite bad.  But we really need to have a sample set of camera images.  I hope that you shoot raw and that you can supply copies of just the 0ev exposure set.  If no raw shots are available, then medium quality jpegs will be fine.

Hi John, 

I uploaded the camera images (12 images) as well as a new panorama I created that is stitched better (not that it makes a difference to main blurriness issue).

Link: https://www.sendspace.com/filegroup/3lfUAE8Y7b5loaECmnhzZBsYl2XZq1HjNsQGPK0gUOBL1g5OL2%2BWDB5rGPgSSzPxdmcZ7RkMxaCMcArDykHbybgY63H5XoCez21aNbekXi8

I need to process these images in batches so correcting them individually is not really an optimal solution.

Thanks,

Hamid

[John Houghton]

On Wednesday, April 27, 2016 at 12:00:37 PM UTC+1, hamid.m...@gmail.com wrote:

I uploaded the camera images (12 images) as well as a new panorama I created that is stitched better (not that it makes a difference to main blurriness issue).

Link: https://www.sendspace.com/filegroup/3lfUAE8Y7b5loaECmnhzZBsYl2XZq1HjNsQGPK0gUOBL1g5OL2%2BWDB5rGPgSSzPxdmcZ7RkMxaCMcArDykHbybgY63H5XoCez21aNbekXi8

I need to process these images in batches so correcting them individually is not really an optimal solution.

The HDR jpg  images were shot in auto exposure mode (Aperture Priority), which is not what is recommended for PTGui.  I picked out 4 images from the sets for a stitch.  I corrected chromatic aberration in Photoshop raw converter in a batch mode.  There is certainly some unsharpness at the edges of the image circle (not unusual), but stitching a single set of images was not so bad.  See https://www.sendspace.com/file/6w6d8g for panorama image. 

John

[hamid.m...@gmail.com]

The HDR jpg  images were shot in auto exposure mode (Aperture Priority), which is not what is recommended for PTGui.  I picked out 4 images from the sets for a stitch.  I corrected chromatic aberration in Photoshop raw converter in a batch mode.  There is certainly some unsharpness at the edges of the image circle (not unusual), but stitching a single set of images was not so bad.  See https://www.sendspace.com/file/6w6d8g for panorama image. 

John

That actually looks really good. I guess I could do the same to the merged HDR images and then run them in PTgui. How did you correct the chromatic aberration? I tried and did not get a match better result.

Hamid

[John Houghton]

On Wednesday, April 27, 2016 at 4:30:57 PM UTC+1, hamid.m...@gmail.com wrote:

That actually looks really good. I guess I could do the same to the merged HDR images and then run them in PTgui. How did you correct the chromatic aberration? I tried and did not get a match better result.

Here's a screenshot of the ACR settings I used (CS6):  http://ge.tt/9bdCO5a2 .  CA correction works best with raw images, but you can often get a reasonable result with jpegs.

John

[John Houghton]

FWIW, just for fun, I tried merging the camera images with Photoshop's merge to hdr and stitched the resulting .hdr files with PTGui.  I generated a true hdr tone map and a fusion output and did a 50-50 merge of both panoramas.  See https://www.sendspace.com/file/7w08gy .

John

[hamid.m...@gmail.com]

Thanks a lot John. I'll try to emulate the same as you did with the HDR images. 

By the way, do you think the images PTgui stitches will have less blur if I shoot in M mode instead of AV?

Best,

Hamid

[John Houghton]

Hamid, M mode is strongly recommended as the blending is so much easier when the images match in the overlap areas.  Don't use auto white balance either.  Blurring will be no different, except that you will not have degradation of the image quality due to the blending of images having very different brightness levels, as can happen in Av mode.

John

[hamid.m...@gmail.com]

On Wednesday, 27 April 2016 21:02:44 UTC+2, John Houghton wrote:

Hamid, M mode is strongly recommended as the blending is so much easier when the images match in the overlap areas.  Don't use auto white balance either.  Blurring will be no different, except that you will not have degradation of the image quality due to the blending of images having very different brightness levels, as can happen in Av mode.

Got it. Thanks a lot for the help John.

Best,

Hamid 

[strarsis]

Hi John,

I also tried removing colour fringes additionally to the automatic chromatic aberration correction (Adobe Lightroom).

But the items, walls, etc with same colour in the fringe range were desaturated, so they look grey/strange.

I tried to narrow the colour range down, but this also made the fringe correction useless.

This is the reason why I currently only use the automatic chromatic abberation feature - it works pretty well except in extreme cases (the light brackets) -

but I cannot go through each bracket shot and intensively check for desaturation - or even mask them out manually, it would take far too much time.

Maybe there is a better tool or way for this?

Thanks and 

with best regards

[John Houghton]

On Thursday, April 28, 2016 at 2:04:16 PM UTC+1, strarsis wrote:

I also tried removing colour fringes additionally to the automatic chromatic aberration correction (Adobe Lightroom).

But the items, walls, etc with same colour in the fringe range were desaturated, so they look grey/strange.

I tried to narrow the colour range down, but this also made the fringe correction useless.

This is the reason why I currently only use the automatic chromatic abberation feature - it works pretty well except in extreme cases (the light brackets) -

but I cannot go through each bracket shot and intensively check for desaturation - or even mask them out manually, it would take far too much time.

Maybe there is a better tool or way for this?

Yes, the defringing tool is a blunt instrument and has to be used with care to avoid affecting other areas of a similar colour.  I usually resort to masks and selections to confine the edits to the intended fringes as far as possible, though this can be time consuming.  Purple is not a common colour generally, but the blues in the sky can easily be affected.

John

[Richard]

I've been suffering with the same problem - but it only seems to be when I shoot RAW.

I prefer RAW as there's more latitude to correct colour temperature etc, but jpegs don't seem to suffer.

Workflow on raw - I'll just shoot the one image (no ghosting with moving subjects as well) and then process to normal exposure and -2 and +2.

Samples attached - camera was set to shoot RAW + Jpeg.

[PTGui Support]

Hi Richard,

Just FYI: one 16 bit tiff file at -2 should give you the same result,
and it's easier to process. See 6.15:
http://www.ptgui.com/support.html#6_15

Kind regards,

New House Internet Services BV
Joost Nieuwenhuijse

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For support see: http://www.ptgui.com/faq/
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[John Houghton]

Richard, There must be something wrong with your workflow to get that result from one set of raw images.  Did you shoot in full manual exposure mode and avoid any auto adjustments in ACR?  And did you create different exposure details for each of the three sets of images so that PTGui can produce the necessary three blend planes?

John

[Keith Martin]

On 28 Apr 2016, at 17:33, Richard wrote:

> Samples attached - camera was set to shoot RAW + Jpeg.

PLEASE don't attach anything to messages! Many people read this by email
and over limited bandwidth connections. :(

k

[Richard]

Yes. Full manual. Using one raw image and sailing down exposure 2 stops, normal and then up 2 stops. I had a play with TIFF as was mentioned and get an absolutely perfect stitch with no errors in the floor detail, and no blur, but this is without any blending of other layers. When using tiff with blending I still get the blur.

More contrast gives me more blur. Eg. When dialling exposure right down to get the windows in the church right, (making everything in the image pretty much black) I get more blur.

Probably is a setting somewhere. Advice on the perfect computer workflow much appreciated here.

Richard

[John Houghton]

On Friday, April 29, 2016 at 10:46:38 AM UTC+1, Richard wrote:

Yes. Full manual. Using one raw image and sailing down exposure 2 stops, normal and then up 2 stops. I had a play with TIFF as was mentioned and get an absolutely perfect stitch with no errors in the floor detail, and no blur, but this is without any blending of other layers. When using tiff with blending I still get the blur.

Richard, I confess I'm not sure I accept these statements.  Take a look at this comparison between the two panoramas:  http://www.ge.tt/4vKce8a2 . Not only is the stitching not perfect, it is different in the two panoramas. Using a template from one for generating the other would at least give a fairer comparison.  If you care to let me have a copy of the raw images (zipped), I would certainly be happy to investigate.

John

[John Houghton]

Richard, Can we see a copy of your pseudo HDR PTGui project file too, please.

John

[Richard]

uploading 8 images now https://www.dropbox.com/sh/q7m30zy0ufucaeh/AABvecQXz-63Ga01cDfah8Vba?dl=0

[Richard]

I've messed around so many times with this, even if I could find the stuff I don't know if it would be any good...

[John Houghton]

Richard, Thanks for uploading the images.  I generated 0ev, -2ev, +2ev sets and generated a 0ev pano with 0ev 16 bit tiff files.  Then fused and hdr panos from all three sets of tiff images.  The images are of good quality, though I haven't spent much time adjusting fusion and hdr parameters.  The results and project files are at https://www.sendspace.com/file/jpw6we .  Obviously, without your project files I cannot say what was going amiss in your efforts, but maybe you can compare my projects with yours and perhaps spot the differences.

John

[John Houghton]

On Friday, April 29, 2016 at 7:51:55 PM UTC+1, Richard wrote:

uploading 8 images now https://www.dropbox.com/sh/q7m30zy0ufucaeh/AABvecQXz-63Ga01cDfah8Vba?dl=0

Richard, One thing I noticed when stitching your images was the vertical parallax error between the upper and lower rows. This is quite large, and you need to adjust the setup of your panohead.  Fortunately, the lower row includes the rotator knob in the view, which most clearly reveals the parallax at the nadir.  See this comparison of two shots with the head spun round through 180 degrees:  http://www.ge.tt/44Xu1Aa2 .  The knob shifts about 10mm, which means the entrance pupil is about 5mm offset from the axis.  To correct this requires that the camera be twisted slightly on its mount to the upper rail.

John   

 

[Richard]

Ah, sometimes I've had the know a bit loose to make the rotation easier - I'll make sure it's tighter. I'm thinking this isn't going to affect parallax at 20 odd feet away...

[John Houghton]

On Saturday, April 30, 2016 at 3:02:34 PM UTC+1, Richard wrote:

Ah, sometimes I've had the know a bit loose to make the rotation easier - I'll make sure it's tighter. I'm thinking this isn't going to affect parallax at 20 odd feet away...

Richard, I doubt that the tightness of the rotator knob has anything to do with this, and you have things a great deal closer than 20 feet away in your panorama.

John   

[Richard]

Had a play with it yesterday and the tightness, when loose to allow easy rotation, causes the NN to fall off the vertical by quite a way. I didn't realise before that this was affecting parallax.

Nonetheless, it still doesn't explain why I've had this blurryness in RAW converted files and not when I've blended JPEGs.

R

[John Houghton]

On Sunday, May 1, 2016 at 8:51:11 PM UTC+1, Richard wrote:

Had a play with it yesterday and the tightness, when loose to allow easy rotation, causes the NN to fall off the vertical by quite a way. I didn't realise before that this was affecting parallax.

Nonetheless, it still doesn't explain why I've had this blurryness in RAW converted files and not when I've blended JPEGs.

Richard, I presume you have had an opportunity to examine the results of my tests, which have no blurryness.  Only if you supply your project file that generates the blurry results is there any hope of solving the mystery.

John