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Messages - Gromit44

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1
Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 22/01/2013, 18:24:00 »
Any success with using just the one image?

I've nearly finished it using just one image. 20 edit steps in NX2 followed by numerous stages in CS6. Perspective has proved the trickiest part - it's taken four days just to get it looking ok (seriously).

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 11/01/2013, 03:17:09 »
Thanks for the help Hayo.

I don't think I'll try the new version of HDR Efex Pro - I've run out of money so I couldn't afford to buy the upgrade anyway.

Btw, v1.2 launches with a preset called '00 Default'. All of its global adjustments are at 0% on launch, so this must be the one you're referring to when you say "apply no preset at all".




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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 18:01:58 »
I'm using HDR Efex Pro v1.2 as a plugin to CS6. It has 32 'Presets' (grouped into realistic, artistic, surreal, landscape, etc) and a 'Custom' option. There's no mention of a 'Default' option.

I'm using ProPhoto RGB in NX2 & CS6. I always convert to 16 bit TIFF when leaving NX2 for more pp in CS6.

(BTW the camera is shooting in Adobe RGB).

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 17:15:27 »
While I couldn't easily get a really good looking result with just the blend if sliders, I also tried loading your three images into HDR Efex Pro 2. By only modifying exposure (-30%) and highlights (-50%) from the defaults, I think I got a fairly natural looking result. With further tweaking you will likely be able to improve the result even more.

Attached is my quick go at it.

Did you set the ev values (-1.7, 0 and +1.3) on the screen before HDR Efex Pro actually launches? I'm getting this:

If I set them to (-1.7, 0, +1.3) I can't duplicate what you did. Which preset did you use?

Here's what I get.

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 17:09:22 »
While I couldn't easily get a really good looking result with just the blend if sliders, I also tried loading your three images into HDR Efex Pro 2. By only modifying exposure (-30%) and highlights (-50%) from the defaults, I think I got a fairly natural looking result. With further tweaking you will likely be able to improve the result even more.

Attached is my quick go at it.

Did you set the ev values (-1.7, 0 and +1.3) on the screen before HDR Efex Pro actually launches? I'm getting this:

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 14:26:16 »


I only need a small say 600-800 pixel sample to try.

OK, I'll email small JPEG sections cropped from the NEFs (using NX2's batch process to make sure the crops are identical).

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 02:01:05 »

Are you trying this on the top layer of the two image layers?

Which is the top layer - the dark one (light bulbs) or the light one (building)?

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 08/01/2013, 01:58:08 »
I always use NEF uncompressed. I've found using lossless compressed only saves around 20-30% on average and I'm not worried about drive space, so I may as well keep all the available data.

The JPEGs are 11-21MB (JPEG Fine) so they're still too big to email. I'll have to reduce them quite a bit to get under the 6MB attachment limit. Will <6MB be good enough for testing?

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 07/01/2013, 19:34:58 »
Perhaps I can have a go (if you could e-mail me the raw files, that would be best).

The NEFs are 74MB each - my email attachment limit is a pathetic 6MB.

If you want to do it with masking, I'd try to make use of the blend if sliders (right click the layer in the layers panel and choose Blending Options…) to have Photoshop automask the brightest spots of the “bright” version of the image, revealing the darker version.

I don't know how to use the 'Blend If' sliders. Nothing seems to happen.  :-[


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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 06/01/2013, 15:14:07 »
BTW2, feathering the mask in CS6 is the best I've managed to come up with.

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Post Processing / Re: Blending shots in Photoshop (CS6)
« on: 06/01/2013, 15:08:00 »
BTW, I've tried HDR (using both Merge to HDR Pro and HDR Efex Pro) and can't get a result that looks realistic.

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Post Processing / Blending shots in Photoshop (CS6)
« on: 06/01/2013, 15:06:06 »
Can anyone think of a technique for blending these night exposures in Photoshop CS6?
 
I’ve got a range of tripod shots of an old 16th century building, with exposures going from -1.7ev to +1.7ev. Small sections of two of them are shown below.
 
The first (2994) is correctly exposed for the light bulbs but the building itself is underexposed. The second (2997) is correctly exposed for the building but the light bulb areas are completely blown out.
 
I’m trying to blend them together so that the building and the bulbs are both correctly exposed throughout. The problem is my Photoshop skills are limited and I can’t find a way of doing it without the edges of the layer mask becoming visible - i.e. if I apply it to the light bulb areas, it also darkens the walls behind (third pic below shows this effect - I’ve exaggerated it to illustrate the problem).
 
Does anyone have any bright ideas? (pun intended ☺). Maybe there’s a way of creating an ‘auto mask’ to replace just the areas that are over a certain level (i.e. the bulbs).

14
Yes, the manual for this lens gives huge DOFs at 14mm and f/8. Here are figures from page 104:

  • 0.54m to infinity when focussed on a subject 1 metre away
  • 0.92m to infinity when focussed on a subject at infinity

So with a focus distance of 210 feet (64m) the DOF should have easily covered both the centre and edges of the building.

I wonder if the reason for the strange behaviour has something to do with the front element of the 14-24 being ashperical.


15
Hello Simon,

One thing your samples show (again) is that, when properly focussed, your lens is pretty darn sharp, even at the edges. So the lens is most likely OK.

I'd agree with that.

So why the big loss in sharpness from side to centre? This, while Depth of Field of the lens at 14mm at f/9 indicates this should not be a problem.

A couple of observations that may explain this:
  • For the centre shot you focussed on the the building that is farthest from the camera, but the sides are much closer (any idea what the distances to the camera where?). For your side shot, the reverse is true. From a depth of field perspective, this is far from optimal and you'd best focus somewhere at a third in between.

Here is an aerial shot of the building - and a layout plan:


The room marked 'H' on the plan (the one nearest 'G') is 180 feet long. The camera was in the centre of the courtyard where the two (pale coloured) walkways meet. From this I estimate the building was 210 feet from the camera at the centre of frame and 180 feet away at the edges. The part of the building at the edges (i.e. where the Christmas trees are) was well forward of the sensor plane though - so even allowing for the CoC calculation below, I'm still surprised that a 30ft difference would have such a large effect.


  • DOF calculations are based on old rules of thumb with an old definition of what is acceptably sharp. With modern cameras, and certainly with the super high pixel count cameras like the D800E, what is acceptable sharpness at pixel level requires a much more stringent definition of acceptable sharpness. The DOF as a result will be much, much, shallower.

Further info regarding the second point: normal calculations for Depth of Field take 0.025mm or even 0.03mm for the “circle of confusion,” with a pixel size of only 4.88µm, this means 5 to 6 pixels (in each direction!), similar to viewing at 20%…

Try the same shot again, but now with focussing somewhere between the closest and farthest points of what you want to have in focus (you may also try going to f/11 though this already may introduce some diffraction effects).

Also, to rule out any environmental or vibration related issues, try the shot at daytime with a short shutter speed.

Unfortunately the place is closed now until February so I can't try any further shots until then.  :( :(
Hope this helps,
Hayo

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