Image uploaded. - Front end of train
Please look at this image, The problem is repeatable.
Load the image and level it by applying +2 degrees rotation
Check the compare,
The original is far more accurate than the correction.
Your views please…
I tried it and it looks fine to me. What exactly should I be looking for?
Mark
Seems fine to me, accurate in what way?
Is this more like what you’re looking for? If so then “Horizon” alone won’t cut it. This has some very complex keystoning going on. I had to use the 8-pt perspective correction in Viewpoint to correct it.
He indicated that merely rotating the image +2 degrees made it look poorer than the original. I’m not certain the perspective issue was the reason for his post, although it may have been. The perspective didn’t change when the image was rotated but the vertical distortion may have seemed more obvious. It’s also not clear if he has access to ViewPoint 3
Mark
Hi Mark, I think I know you from POTN. I was also uncertain what he was looking for but if one straightens the curb using Horizon only, then the train is pointing down and the building leans right. I thought this might be his reason for saying…The original looked better.
I’m new to DPL although I’ve had DOP v8-v11. I like it a lot! You seem to be an expert, so I may be calling on you for advice. 
Yes, that is me over at POTN. As I said, you may be correct about the perspective issue. Perhaps he will get back to us and we’ll know for sure.
I had no experience with Optics Pro, but I have been using PhotoLab almost daily since version 1 was released in late 2017. I do have significant experience with PhotoLab but I wouldn’t necessarily characterize myself as an expert. Of course there are varying degrees of expertise and I’m much more knowledgeable about some aspects of PhotoLab than I am of others, I’d be very happy to assist you in any way I can, assuming I actually know the answer to any questions you pose.
This is a very knowledgeable community with a lot of input by DXO staff. It would be a rare question or issue that couldn’t be answered by someone here.
Mark
Not sure of either images, you have a building in the background, which usually are built straight, in both images its either in angle left or right, the train ramp isn’t straight so the entire image look shot with rotated camera and not corrected. With VP it could be better corrected but at least horizon from the building should get a good start, not the train.
bobmunden n’est pas très clair dans ses explications !
Si on suppose que ce qui ne va pas, c’est la géométrie de l’image, mon analyse est la suivante :
La photo n’a pas besoin de rotation de l’horizon (ou alors très peu). En effet si on se base sur le bâtiment, on peut estimer qu’une ligne verticale passant par le milieu de l’image est confondue avec la verticale du bâtiment.
Par contre l’axe de prise de vue n’est manifestement pas perpendiculaire à la voie ! Si c’était le cas le bord inférieur serait horizontal.
Comme de plus on n’a aucun moyen de savoir si la voie et le bâtiment sont parallèles (et il y a des chances qu’ils ne le soient pas), il n’y a pas de corrections exactes qui soient réellement possibles : les lignes de fuite sont différentes.
On peut essayer d’approcher la vérité en utilisant ViewPack et la correction 8 points, mais ça restera une approche.
bobmunden is not very clear in his explanations!
If we assume that what is wrong is the geometry of the image, my analysis is as follows:
The photo does not need to rotate the horizon (or very little). Indeed if we base ourselves on the building, we can estimate that a vertical line passing through the middle of the image is confused with the vertical of the building.
On the other hand, the shooting axis is obviously not perpendicular to the track! If this were the case the bottom edge would be horizontal.
Since there is also no way of knowing if the track and the building are parallel (and there are chances that they are not), there are no exact corrections that are really possible: vanishing lines are different.
We can try to approach the truth using ViewPack and 8 point correction, but it will remain an approach.
Here’s original left and corrected right taken as a screen grab
The original appears more accurate, the corrected has pin cushion.
This isn’t the first time I’ve had this problem with railway track photographed at 90 deg.
I’ve checked the Camera and distortion correction is enabled. Possibly DxO is correcting something thats already been done in camera and is now driving it out of true.
Are there any recommendations for using or not using in camera corrections?
What have you use for level correction?
Only level bar or also VP?
Have you tried just the level from the building or the train door?
*something wrong with the right image for sure
Is your original file a raw or a jpeg? If it is a raw file would you be willing to attach it so we can download it and try it ourselves. If it is a jpeg do you have RGB images set for no corrections in the General tab of preferences? If your jpeg image already has lens distortion applied in-camera you don’t want PhotoLab to apply lens distortion characteristics to it a second time.
Mark
Hello @bobmurden,
Can you upload your photo (the original one from the camera) here or send it to me by MP ? (with the .dop file). So we can analyse it ?
Regards,
Marie
In Irfanview no problem rotating 2 degrees. Straight lines. Also in ViewNx.
George
PS.
Do you shoot raw or jpg. If you shoot raw than the in camera correction isn’t used I think
Thanks for your input guys.
I’ll do some test shots to see if dual over processing is happening and check if camera lens corrections are being applied in raw. It also opens up the question should other in camera processes like high iso noise reduction be used or long exposure noise reduction. I’ve also had overexposed corners suggesting the vignetting correction had been done twice.
Is there a correct method of delivery to photolab, i.e. have default settings in camera been expected or should they be turned off.??
A raw file isn’t an image it is a set of instructions to a raw converter
(PL in this case). I’m fairly sure that the camera settings only affect camera generated jpeg’s or tiff’s if the camera does them. It is certainly the case with my gear as I can set it up to produce excellent jpg’s but the associated raw is very different.
Hope this helps.
1 Like
** Answered **
Canon Cameras from digic hardware version 8 are now making lens corrections possible in camera
It’s known as Digital Lens optimiser and can be turned on and off in the menu system.
If you want DxO to do the job then you need to turn it off.
This feature was available in Canon DPP, and they’re now moved it Camera side
I would imagine most of us would want to stick with DxO to do the lens corrections as they can be adjusted to taste.
This is a simple issue of perspective, not “horizon”. The camera position is clearly not quite level, nor is the shot taken at perfect right angles to the platform edge. Hence there is convergence (vanishing point to the right). Also unless the building is perfectly parallel to the platform (possible, but may not be), another difference in perspective is introduced. It may not be possible to reconcile all these issues. In PL, you would need to use viewpoint and employ the separate adjustments. Personally I find this kind of image easier to correct in Photoshop with the perspective crop tool, but “perfection” may be impossible.