Forum: Q & A

Thread: exposure problems

back to threads list | this thread is closed
Search the forums:
messages 16-28 of 28
first prev prev 1 2 next next last
Author  Message 
Smooth

Posts: 4257
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: exposure problems
Posted: 26 Feb 2013 at 13:21 GMT

John Houghton said:

Smooth said:

I didn't see any need to reverse the image order as they were shot in the correct rotation.
There was no need to reverse the images, but doing so reveals a difference in tone between neighbouring images, which is what's troubling Kasenyee.
Yeah I get it John, but it just wasn't necessary.

John Houghton said:

PTGui doesn't mind which way the camera is turned.

John
No, but "some" panoheads do.

Regards, Smooth cool
www.omnipix.com.au
alert moderator
enbilaman

Posts: 148
Location:
Registered: 3 Mar 2006
Re: exposure problems
Posted: 26 Feb 2013 at 16:53 GMT

kasenyee said:

the problem comes in images 5/6/7/ and 14/15/16. that area seems to change in exposure. I see it even more when i do a stitch - using PTGui

thanks for all your help guys
much appreciated!

I am sorry not having a valid answer to your OP.
Nevertheless may I ask you (slightly OT):
- Why do you shoot so many (i.e., 2 x 8=16) photos?
6H + 1Z + 1 (or 2)N are usually shot with a Nikon DX camera and the 16 mm FE lens. BTW skipping one image from two of yours (i.e. inputting only 8) lets you enough of them to cover the whole sphere...
- Was the NPP correctly centered on the rotational axis?
alert moderator
mediavets

Posts: 2143
Location: Isleham, Cambs., United Kingdom
Registered: 8 Feb 2008
Re: exposure problems
Posted: 26 Feb 2013 at 18:31 GMT

enbilaman said:

6H + 1Z + 1 (or 2)N are usually shot with a Nikon DX camera and the 16 mm FE lens.


I think you meant Nikon FX?

Andrew
alert moderator
kasenyee

Posts: 111
Location: Toronto, Canada
Registered: 22 Jun 2012
Re: exposure problems
Posted: 26 Feb 2013 at 23:29 GMT
hey guys
thanks for all your help!
that's are the same results I'm getting, however, PTGui doesn't seem to be able to blend them very well. Some parts of the trim (halfway up the wall) have a clear difference in tone.
I am shooting HDR, usually between +2/+3 N and -2/-3. I haven't had a chance to raise some capital to get photomatix.

would anyone have any suggestions on settings/ways of blending the images better through PTGui?

thanks again!

alex
alert moderator
kasenyee

Posts: 111
Location: Toronto, Canada
Registered: 22 Jun 2012
Re: exposure problems
Posted: 26 Feb 2013 at 23:36 GMT

enbilaman said:

kasenyee said:

- Was the NPP correctly centered on the rotational axis?

For the first few days, my settings were incorrect. I only had power for my laptop every few days so I wasn't able to check my settings often and it had shifted slightly. I didn't bother changing them until later - all the tests I ran didn't show any stitching errors so i left it until I had power for a good length of time.

I shoot 2x8 because I have yet to try shooting/stitching the Z - and didn't want to start on a lengthy trip - so i played it safe. also, I shoot 8 because sometimes I end up forgetting a rotation and so I just shoot 8 to cover myself just in case.
alert moderator
John Houghton

Posts: 3896
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: exposure problems
Posted: 27 Feb 2013 at 8:43 GMT

kasenyee said:

PTGui doesn't seem to be able to blend them very well. Some parts of the trim (halfway up the wall) have a clear difference in tone.

Alex, I don't see what the problem is. PTGui has blended the images well. I've uploaded a copy of my stitch to ge.tt/2Lw3AaZ/v/0 .

John
alert moderator
kasenyee

Posts: 111
Location: Toronto, Canada
Registered: 22 Jun 2012
Re: exposure problems
Posted: 1 Mar 2013 at 2:35 GMT
alrighty, guess I'm seeing somethign that's not actually there or a problem.

Thanks again for alll yoru help every!
very much apreciated!
alert moderator
Smooth

Posts: 4257
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: exposure problems
Posted: 1 Mar 2013 at 4:04 GMT
Show us the problem.
So far we have tested your images and all seems fine.
Maybe it's the blender your using?

Regards, Smooth cool
www.omnipix.com.au
alert moderator
kasenyee

Posts: 111
Location: Toronto, Canada
Registered: 22 Jun 2012
Re: exposure problems
Posted: 1 Mar 2013 at 17:29 GMT

Smooth said:

Show us the problem.
So far we have tested your images and all seems fine.
Maybe it's the blender your using?

Regards, Smooth cool
www.omnipix.com.au


ge.tt/4MCQKoZ?c
here's where i see my problem. areas are circled. there's also another example of some exposure weirdness, where the top shots an bottom shots vary and don't blend well.

thanks again
alex
alert moderator
John Houghton

Posts: 3896
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: exposure problems
Posted: 1 Mar 2013 at 22:24 GMT
Alex, Again, I still don't see anything amiss with the blending in the wooden dado rails. The points marked with circles look identical to the same areas in the original images. There is certainly a noticeable blending issue in the wall below the rail that's circled. The images are quite different there, but a spot of manual blending in that area might well improve things with the help of some masking, given the large overlap available.

The waterfall panorama is not by any means a static scene and would benefit from being blended with a smart blender (which hides stitching errors with intelligent routing of the seam). I would use Smartblend on a Windows system, but that's not available on Mac. The latest versions of Enblend do smart blending also, so it would be worth trying that.

John
alert moderator
DennisS

Posts: 1759
Location: Los Anglels, United States
Registered: 1 Sep 2007
Re: exposure problems
Posted: 1 Mar 2013 at 23:44 GMT
Alex,

I also see absolutely no issues with the walls and such. The different colors in the molding look like either reflections or a different style of wood being used. Look at the area around the molding. The blending of the wall above and below does not suffer the same issue as the molding. I do not see any issues with the other three areas. Overall I would say this pano stitched and blended about as well as it can. I will not say 100% perfect because I cannot see the full size images.

As far as the waterfall is concerned, it stitches quite nicely. It appears that the wind was not blowing too hard, so all the trees and such look like they did not move around much.

You have twice as many pictures as you need. Remove all the odd numbered pictures and your pano still stitches. You have way too much overlap for the number of images you took. You need to increase your angle of rotation and take fewer pictures overall. 25% overlap is a great place to start. It looks like you have 50% overlap. Using half of the pictures just barely allows enough overlap, but it does work.

The water moved around a lot. Smartblend does a very nice job on the water.

Looking down at the rotator, you need to move your vertical rail over to the left. There is a saw tooth pattern. You need to move the direction the teeth are pointing. Once you get a circle, you are much closer to "the point" than before.

Simply by loading the images, removing all the odd numbered ones, auto aligning, delete worst control points and optimizing, I got a maximum control point distance of around 3. Not bad for a quick and dirty stitch. If you move your vertical arm over a bit and get your rotator to look round, the maximum distance will come down.

So far I see nothing major. The little items I pointed out can be very easily corrected.

Dennis
alert moderator
Smooth

Posts: 4257
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: exposure problems
Posted: 2 Mar 2013 at 4:33 GMT
Yeah, I don't see any real issue they to speak of outside of a blending seam that is caused from your incorrect panohead alignment. As John points out, because of the serious amount of overlap you could mask this area to improve it.

But the reality is as Michel and Dennis mentioned is that you need to first correct your NPP. Things will work a lot better once you have this set up correctly. Then you will also be able to shoot the correct amount of shots to complete your panorama, without using your current scatter gun approach.

Learn how to do this:
www.easypano.com/forum/display_topic_threads.asp?...
www.johnhpanos.com/epcalib.htm
www.rosaurophotography.com/html/technical7.html

Until you know and understand this, you will always be a step behind.

Regards, Smooth cool
www.omnipix.com.au
alert moderator
kasenyee

Posts: 111
Location: Toronto, Canada
Registered: 22 Jun 2012
Re: exposure problems
Posted: 2 Mar 2013 at 5:41 GMT
updated: 2 Mar 2013 at 5:44 GMT

DennisS said:

Remove all the odd numbered pictures and your pano still stitches. You have way too much overlap for the number of images you took.
Dennis


what do you mean by removing the odd numbered pictures? literally ignore every other image?

this may sound a bit naive, and i understand my settings aren't "perfect", but is it that big a deal that my lower rail isn't set perfectly? from the 200+ pans i did on my trip, only a few had minor issues.

thanks
alex
alert moderator
messages 16-28 of 28
first prev prev 1 2 next next last