Perspective Control in Action

[Naughty Nigel]

As discused in the Wells thread, I have uploaded a photograph of our local church, which was taken at close range using the 14 mm end of my 14 ~ 54 lens. Before I applied the perspective control it looked as if it was about to collapse in a heap! As it was I had to be careful not to make the wall at the east end of the nave look un-natural.

The perspective control also seems to make images look a bit grainy where they have been stretched a lot.

Taken on E1 in RAW and edited in CS3

[knikki]

Re: Perspective Control in Action

Looks good on my monitor here in work and at this size I can't see any issues with the "stretched" pixels.

In the past what I have done is get the RAW file to how I like it then save the image as a TIFF. Makes it bigger but the advantage is that a TIFF file is non destructive, so will take a fair bit of messing with before it starts to lose things.

[Naughty Nigel]

Re: Perspective Control in Action

Hi Knikki,
I converted the RAW file to a TIFF for adjustment before sharpening and saving to Jpeg.

The grainy effect is difficult to see at this resolution, but a close examintion of the blue sky areas will show it. Interestingly, PS also came up with an 'out of gamut' warning for the pixels concerned after stretching, but not before.

I have seen the same effect in high res MF scanned images, so it is not specific to lower resolution digital cameras.

Nigel.

[knikki]

Re: Perspective Control in Action

"Out Of Gamut" warning?

Try setting your PS Workspace to Adobe 1998 and see if that cures it

Most of my scans from the 6x6 trannies are near 500mb & 48bit colour in size and I have not seen that warning before

[Naughty Nigel]

Re: Perspective Control in Action

If you switch on View, Gammut Warning?

I only tried it because I could see strange effects in the stretched sky.

I normally use Adobe RGB unless I am scanning film.

Nigel

[RogerMac]

Re: Perspective Control in Action

Hi Nigel

Nice to see you here

Roger

[Naughty Nigel]

Re: Perspective Control in Action

Hi Roger,
Good to see you too.

Are there any dangerous dogs around here?

Nigel.

[RogerMac]

Re: Perspective Control in Action

Hi Roger,
Good to see you too.

Are there any dangerous dogs around here?

Nigel.

Have not spotted any here! Not even ones screaming "small sensor" at athe least opportunity

Roger

[RogerMac]

Re: Perspective Control in Action

You have been busy - only here a few days and already 14 posts! When you get to 20 your "rep power" will flip over to 1

[Naughty Nigel]

Re: Perspective Control in Action

For comparison, I have uploaded a copy of the original file, which shows how bad the converging verticals were. I also enhanced the colours somewhat using B&W filters in PS.

[snaarman]

Re: Perspective Control in Action

I am quite a fan of perspective correction (in my film days I had a PC shift Nikkor). These days generally use PTlens to correct the 14-42 and the 11-22 lenses, and this offers H and V perspective as well as the more usual distortion correction.

However I find it usually makes the buildings look rather "squat" - so I also apply an arbitary amount of vertical stretch as well, until it looks "right"

Pete

[Naughty Nigel]

Re: Perspective Control in Action

Interesting point. As it happens, this building is very tall, (the tower is roughly 90 feet) so it usually looks better a little more squat.

I will bear that in mind for future adjustments though.