Image Quality

Specifically for the discussion of the A-mount DSLR range
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sury
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Re: Image Quality

Unread post by sury »

I apologize for my PS skills or (more like) lack thereof. Here is an image saved with highest compression from original extra fine JPEG. The second image is saved in PS with medium resolution and the third is the original. From the histogram I can see it was exposed to left. I thought this might be a good example. Could some one explain (tech me) it to me how to coax more details out of Extra fine JPEG?

With best regards,
Sury

IDC version
Image

PS version
Image

Original
Image
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David Kilpatrick
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Re: Image Quality

Unread post by David Kilpatrick »

What do you mean by 'more details'? More physical detail (sharpness, resolution) or more tonal detail (shadow detail, midtone contrast, highlight detail)?

The standard answer is - shoot raw, then you can adjust everything. If you shoot JPEG of any kind you can certainly adjust, but you will lose information, as you can never add something which is not there but it's easy to compress some parts of a image tone and colour scale while expanding others - once done, not reversible.

David
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sury
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Re: Image Quality

Unread post by sury »

I meant more physical details as you described. I did not consider the tonal details in my statement. I guess in addition to being tone deaf and I am tone blind as well. :D I have, due to my ignorance, associated shadow and highlight details with sharpness.

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Sury
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Re: Image Quality

Unread post by David Kilpatrick »

While I would always shoot with sharpness at zero, you may find that setting sRGB space, Landscape colour mode, and increasing sharpness to +1 or +2 (+3 is a bit extreme) gives you the extra look of detail you want in an Extra Fine JPEG for this type of subject.

David
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sury
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Re: Image Quality

Unread post by sury »

David,
I will keep that tip in mind. As a modest digression, I want to know why it is preferred to shoot in RAW? Let me bound the statement with a framework. I am an amateur (not a good one) who likes photography. I am totally agnostic to types of photography (landscapes, portraits, candids, family, travel, macro, flash, moon, manual lenses with adapters etc). I am basically your typical weekend warrior. Given those boundary conditions do I need to or do I want to shoot in RAW?

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Sury
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Mike
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Re: Image Quality

Unread post by Mike »

sury wrote:I am an amateur (not a good one) who likes photography. Sury
I'm in the same boat. However, I like to think I'm getting better! When I stop getting better it won't be fun anymore.
I think you can answer your own question by shooting RAW and JPEG for a while and playing with the trial version of DxO http://dxo.com/us/photo/trial_version or similar software.

Mike
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Re: Image Quality

Unread post by stevecim »

I'm also on the same boat :), I always shoot RAW and Jpg. 80% the jpg are fine for what I do, but when I have a image where I don't like the jpg, then go to the RAW to see if I can improve it. Has I improve my RAW handling skills, I will reprocess older photos that i like but was no 100% happy with. I'm always amazed at how much can be recovered from a RAW photo. If anything has a newbie RAW is more important to me has I make lots of mistakes :) i.e last Christmas I was shooting in my mums lounge which is maybe 2.5 x 2.5 m, set my lens to f8 to get the DOF then tried to use the popup flash, I guess the popup flash was not strong enough at f8 has most photos where very dark. processing the RAW recovered the photos good enough for 6x4 prints :)
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Re: Image Quality

Unread post by David Kilpatrick »

I use Adobe Camera Raw (Photoshop CS4) for raw. To give you an idea, you can retouch dust spots or insects in the sky atthe raw stage. You can apply graduated filters, or local dodge and burn type corrections for ANY parameter - exposure, saturation, contrast or combinations. You can change WB freely, alter overall exposure, change noise reduction - the list is endless.

Then when you export all this, you get a better JPEG than the camera JPEG.

And all the retouching, red eye correction, sky gradations, opened shadows, fill light, highlight recovery, vignette correction CA removal - it's all saved with the raw file so next time you go back to the image, every change is recorded. But the raw file remains UNTOUCHED, all you have recorded is a set of instructions to go with it. You can reverse everything or tweak a few things.

In short, it is more than a negative ever was. Negatives could not remember your hand printing. ACR can.

David
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sury
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Re: Image Quality

Unread post by sury »

David and et al,
Thank you. Now I am off to Fry's electronics (local/regional Electronic store) for that 1.5Tb drive
for US$115. :) I guess I might add a NAS enclosure for another $50. :lol:

With best regards,
Sury
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Re: Image Quality

Unread post by David Kilpatrick »

The cheapest way to get all the functions I mentioned is, of course, Adobe Lightroom. The raw converter has all the correction tools of ACR CS4. I have both, I prefer the 'one image at a time' approach of ACR but sometimes use Lightroom to deal with big sets of shots.

David
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Dusty
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Re: Image Quality

Unread post by Dusty »

Sury,

Have you ever had a JPEG you shot and then wished you had set a different setting on the camera? Just using Sony's IDC you can (in RAW) go back and make the adjustments that you could have made on the camera. How would that scene look in Vivid mode? IDC can output a JPEG from RAW that would be like Vivid mode. Basically, in RAW you have the ability to output a JPEG that YOU can change parameters on, regardless of what the camera's JPEG engine thinks it should look like.

Dusty
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sury
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Re: Image Quality

Unread post by sury »

Dusty,
More than my share of regrets on wrong settings. My intention is not to debate the pros and cons of various shooting styles in terms of technical superiority but in terms of applicability. For example, at a recent birthday event of a friend, I wish I shot in RAW precisely for the reason you mentioned. Luckily I was able to recover from erroneous settings right away and proves your point.

I was more influenced by gil in dpr who is a big jpeg shooter.

With best regards,
Sury
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Dusty
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Re: Image Quality

Unread post by Dusty »

sury wrote: I was more influenced by gil in dpr who is a big jpeg shooter.

With best regards,
Sury
Back in the film days there were those who shot Polaroids or - horror of horrors - my old roommate, who Had a nice Canon, but threw away the negatives!

I always knew that I could get more out a photo if I had a negative to work with. Sometimes you spent a lot of time burning, dodging, of making test prints to get things right, but it was better to recover that shot than not to have it.

I realize you can do a lot with a high quality JPEG, but you can always do more with a RAW file!

Dusty
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