Anyone Want To Stitch a Pano?

[nebulosity.]

G’day everyone,

The paddock of wheat about 20m from my observatory has been slowly ripening and turning golden, and I though it would make a nice nightscape.

I had a look around and found spot that I thought would work well and figured out the night of the 23rd at 9:28 would be when I take it.

I needed to take two rows of images, which would take around six minuets each, the plan was to time it so that as soon as I had finished taking the top row of the milky way, the 70% Moon would break above the horizon and light up the wheat for the bottom row.

Well the time came, I jumped on the motor bike drove to my spot, set up the tripod, took the images and it all went to plan.

As far as I can the images look great but I have not been able to stitch them together as my panorama program is not that crash hot and gets totally baffled. I have been wondering what to do, as I don’t want to waste all the effort I spent trying to capture it, and I don’t want to spend a lot of money on a program for a once off image, so I’ve finally decided to ask wether any body on here would like to stitch it together for me?

I uploaded the 18 Tiff images onto dropbox and they can be got here (https://www.dropbox.com/sh/10nkm8hh94gzku5/erJdg6ilvI).

I downsized them to 60% but they are still around 17.3 mb each.

If anyone stitches it together do you reckon you could upload the unprocessed version somewhere and post a link?

Everyone feel free to process the image to your liking and post it up, I’d love to see how it turns out.


Info and camera settings are:

Camera, Panasonic GX1 (micro 4/3)

lens, 20mm f.17 (40mm equivalent on a full frame camera)

Exposure, 20 sec iso 1600.

Two rows of nine images.

Thanks a lot,
Jo

PS. if there is any trouble with the link please let me know.

[redomatic]

Jo, I had a quick go.

I had some issues.... and I know nothing about your camera so I can't provide too much specific feedback.

(1) When I take Multiple Row Panoramas I always do it one way (i.e from left to right for both rows.) There are two reasons:(a) The star movement is standard between frames (well relatively); and
(b) It it's easier to visualize in the stitching software. (i.e. 1 goes above 9, 2 and 10, 3, and 11, etc.)

(2) When you setting up the camera, try and get it as level as possible - it make a huge difference when stitching... I use a bubble level in the hot shoe ($5 bucks on e-bay).

(3) There is a difference in exposure between the Upper and Lower shots.(a) I couldn't see the difference in your EXIF data, but if you compare "P1380082.tiff" and "P1380100.tiff" there is a significant difference where they overlap.
(b) It looks more than just vignetting.
(c) It is also there between frames but not as bad (so it may be vignetting).
(d) Anyone else have any ideas? More overlap to reduce Vignetting?
This was the end result with some saturation added!
I didn't attach the full detail one owing to the significant difference in exposure (point 3). Made it hard to make the image workable.

Compare the output to this, which I did in less processing time (I am comparing the processing time not the picture) - It is incredibly important that your original setup is the best you can or it will take heaps of time in post processing, and you may never get the result you wanted - It's a learning exercise and I can't understate it's importance.
http://www.iceinspace.com.au/forum/showthread.php?t=112742

[mithrandir]

Jo, I can stitch 17 of them. I guess P1380082 should be top left but it doesn't have enough in common with 83 and 100 for AutoPano to link it in. Do you want it like that?

[nebulosity.]

Thanks Andrew, yeah try the 17, that would be still cool.

Jo

[gregbradley]

I find it quite common to have to manually add some stitching points for PTGui Pro. It does most of it but there are always a few that need the points.

Your result looks like the camera was not set to manual mode and was changing the exposure, metering each shot?

The camera needs to be set to manual, autofocus off, auto metering is also off and the settings made manually. Perhaps you did this.

It may need some expsoure compensation in the stitching process. PT Gui Pro can do that.

Greg.

[mithrandir]

If I've go the permissions correct, when Dropbox finishes synching ->
https://www.dropbox.com/sh/6q9zitibcyg4fqz/GBFYSbuI1R

AutoPano does lens distortion correction and some colour correction, but it's otherwise untouched.

[atkinsonr]

If you shoot in RAW, micro 4/3rd cameras like the GX1 will add lens profile information to the images so that software like Lightroom can correct vignetting and other lens aberrations automatically.

Also it's good to overlap each frame by about 1/3; you really want to avoid stitching the edges of the frame if you can.

Also important to make sure the camera is set to Manual and aperture (as well as exposure time) is consistent across all frames (maybe you did this - just going on Michael's remarks).

If you did have the aperture on Manual and it still shot inconsistently, try closing the aperture down 1 stop and trying the whole set again. The image will be slightly darker but you should reduce the exposure difference.

Great location / capture. Well worth setting up again if you get the chance!

[nebulosity.]

Thanks heaps for having a go, and for your great advice :thumbsup:

next time I'll take each row starting from the left and make sure my tripod is very level.

[nebulosity.]

G'day Greg, yeah I had the camera on manual, I set the exposure, aperture, iso, and had the white balance on your recommended 4350 Kelvin.
None of the settings were changed while capturing.

Jo

[nebulosity.]

Yes, they were taking in RAW and then converted to Tiff's.



Thanks, yeah I might have another go next week if the moon's right.

Jo

[nebulosity.]

Thanks for doing this Andrew :thumbsup: it downloaded fine so I'll have a go at processing.

[iceman]

Looks like a great location! Well composed.

[nebulosity.]

Thanks a lot Mike :thumbsup:

I've done a process of Andrews stitched image, what do you reckon?

It took a long time working with dodge and burn brushes to sort out the exposure differences but I think it's acceptable now :thumbsup:

The only thing I'm not happy with is the lefthand top corner, I need to do a better clone job there.

I'd like to know what you think of the colours, I only had a quick fiddle with them and will probably do a few repros.

Cheers
Jo

If you want to have a process of my "exposure corrected image" let me know and I'll upload it to dropbox.

[gregbradley]

Looking better. Was there a polarising filter on the lens? I am wondering what caused the differences in exposure.

Greg.

[nebulosity.]

No, just the standard uv protector filter.

[mithrandir]

If you expect the light level to change while you are shooting (eg if it is before astronomical twilight) it would be easier to stitch if you started at one side and worked across. I'll admit that's hard work doing it by hand, and auto panorama heads aren't cheap.
1 4 5 8
2 3 6 7
and so on.
Or use a wider angle lens. A 20mm would cover about the same area as four 40mm frames. On my gear a 40mm covers close to 33x22 degrees. A 20 mm does 66x44 degrees. That would do your pano in one pass.

[redomatic]

Jo, I'm still with Greg wondering about the exposure.

You seem confident that there there wasn't any difference in settings.

Can you compare the RAW files for "P1380082.tiff" and "P1380100.tiff" and see if there is a significant difference in exposure where they overlap? to try and determine if it was pre or post conversion.

If I assume they were taken at 9:30'ish there should be a significant difference in the location light. (between 9:30 and 9:42).

There is a significant difference, more than I can explain.

and as you probably realize there is quite amount of effort in dodging and burning.... especially when you don't need to.

[nebulosity.]

Thanks for all your help guys, heres my final repro and some shots I got last night.

Cheers
Jo

PS the difference in exposure between the first and last shots on the pano would have been because of the moon rise.

[nebulosity.]

Good Idea, thanks Andrew :thumbsup:

[gregbradley]

PS the difference in exposure between the first and last shots on the pano would have been because of the moon rise.[/QUOTE]

Oh I see. That would be tricky. I suppose speed of acquiring the shot would be everything in that scenario.

I know from my Astro CCD imaging how quickly light levels change at dusk and dawn as the CCD image gives a number readout of the brightest part of the image and it can change considerably just 20 seconds apart.

Greg.

[redomatic]

Thanks greg - I had no idea! - I normally stay away from any moon!!