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GH2 impressions

Terry

New member
I might later, yeah... But the GH and G firmware can't correct it when it's in the OOF areas like this. Which is why I tried to get the potentially troubled areas in the OOF portion of the scene. You're right tho. The camera's firmware does a lot of shifting of the color plates for that lens and images that are all sharp and in focus are typically well corrected.

The one UWA I mentioned that also has a CA problem is the exact same deal except I have to correct for it in ACR by hand. One setting fits all images and almost all of it's images need it. The difference between it and the Lumix is only that the GH1 does it for the Lumix automatically without user intervention. Handy.
OK, how in the world are you throwing much out of focus (and why) with this lens? Are you just trying to go the minimum focus distance to try it?

At 7mm at f4.0 with a subject distance of 3 feet the you should be OK from 1.42 feet to infinity hyperfocal 2.7 feet
At 14mm at f4.0 hyperfocal is 10.8 feet.
 

kit laughlin

Subscriber Member
@ Tesselator: how about posting real images? By this term 'real', I mean an image that you took to be used for a purpose, focussed on something, properly exposed, etc. I think I could get the 12–24/2.8 to show this kind of CA if I duplicated those setups, but that would give no indication of how the lens performs in 'battle conditions'.

And you wrote:

It's also cool that we have different opinions. That's the human condition. Sharing such opinions is fun for me.
That's all fine, but as a philosophy prof. once said to me, "Opinions are like *bottoms*; everyone has one—we want to know why this opinion is more valuable than that one". If the goal is fun, no problem, but sometimes it's hard to divine the intention from how you write (again, as an ex-philosopher, to me you can sound like a logician, with the weight that this entails, but you might be intending rhetoric, or polemic).

Then again, you might be able to see things that others can't, too. If this is the case, evidence please.

Best wishes, KL
 
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henningw

Member
I am with Amin on this one. In the situations I use my 7-14 I am very happy with the lens and do not see problems with CA in my copy.
Count me in as agreeing with Amin.

As for experience with wide angles, I've used over a hundred with angles of view greater than 90 degrees.

As for your example of the Rokkor 16mm; it's dead easy designing a fisheye with low chromatic aberration in comparison with rectilinear lenses of the same focal length. Have a look at the concurrent 20mm/2.8 Rokkor. You in particular criticize reviewers for comparing apples and oranges, so you leave yourself open in this regard.

The 7-14 Panasonic is an outstanding lens, even at the price.

Henning
 

CPWarner

Member
Count me in as agreeing with Amin.

As for experience with wide angles, I've used over a hundred with angles of view greater than 90 degrees.

As for your example of the Rokkor 16mm; it's dead easy designing a fisheye with low chromatic aberration in comparison with rectilinear lenses of the same focal length. Have a look at the concurrent 20mm/2.8 Rokkor. You in particular criticize reviewers for comparing apples and oranges, so you leave yourself open in this regard.

The 7-14 Panasonic is an outstanding lens, even at the price.

Henning
Henning, I am assuming that your remarks are intended for another poster and not me as I never have owned the Rokkor 16mm and was not discussing comparisons of different varieties of fruit!

Cliff
 

Amin

Active member
Tesselator showed two types of CA. The lens cap crop he showed crop was greater than 100% and processed to maximally show fringing. I can assure anyone who shoots on a Panasonic body using Lightroom 3 that lateral CA is just not a significant issue with this lens in practice. I have tested quite a few lenses by taking identical pictures of the front of my house, and the region I showed in the crops above is where lateral CA rears its head from the great majority of them.

The other crops Tesselator showed are clearly not lateral CA, because the fringing is of a single color completely surrounding blown highlights. While this could be related to a sensor/microlens issue, it's probably longitudinal CA. If I look for this type of cyan discoloration surrounding blown highlights, I can see it in selected images from lots of lenses, and the Pana 7-14 is IMO not especially poor in this aspect.
 

henningw

Member
Henning, I am assuming that your remarks are intended for another poster and not me as I never have owned the Rokkor 16mm and was not discussing comparisons of different varieties of fruit!

Cliff
No, Cliff, I'm definitely not referring to you and your discussions. It was a poor quote, as your comment was the one I was agreeing with. I then jumped to something else which did not involve you at all.

In any case, the 7-14 performs admirably with respect to lateral chromatic aberration.

Henning
 

Tesselator

New member
Tesselator showed two types of CA. The lens cap crop he showed crop was greater than 100% and processed to maximally show fringing. I can assure anyone who shoots on a Panasonic body using Lightroom 3 that lateral CA is just not a significant issue with this lens in practice. I have tested quite a few lenses by taking identical pictures of the front of my house, and the region I showed in the crops above is where lateral CA rears its head from the great majority of them.

The other crops Tesselator showed are clearly not lateral CA, because the fringing is of a single color completely surrounding blown highlights. While this could be related to a sensor/microlens issue, it's probably longitudinal CA. If I look for this type of cyan discoloration surrounding blown highlights, I can see it in selected images from lots of lenses, and the Pana 7-14 is IMO not especially poor in this aspect.
Yup! I agree with that assessment. Although the LoCA in my opinion is approaching "poor" - but not quite "poor", and true, "not especially poor". On the other hand unless it's come down in price it's the worst I've seen in that price range and poorer than many many lenses which typically sell for hundreds less. And this is why I originally posted that people considering the purchase of the Lumix should be aware of it.

Also to note is that we do not know how the lens performs in terms of LaCA as the camera corrects for that before we ever get to see the images. It could be fantastic and it could be the worst in the world. ;) I guess we would need to put it on a M4/3 body that has no such correction. Has anyone done this and also tested for LaCA yet?

I do like the lens! I'm not trying to unwarrantedly knock it. And if you need AF on M4/3 in that focal range I think it's the best option there is. I dunno the Oly so well - is it better or worse do you think?
 

Jonas

Active member
(...)
Also to note is that we do not know how the lens performs in terms of LaCA as the camera corrects for that before we ever get to see the images. It could be fantastic and it could be the worst in the world. ;) I guess we would need to put it on a M4/3 body that has no such correction. Has anyone done this and also tested for LaCA yet?

I do like the lens! I'm not trying to unwarrantedly knock it. And if you need AF on M4/3 in that focal range I think it's the best option there is. I dunno the Oly so well - is it better or worse do you think?
Checking the lens for uncorrected LaCA... isn't that as easy as take the image in raw format and open it using Raw Therapee or any other converter not supporting the auto correction feature? Maybe Raw Therapee doesn't support the camera as of yet? Plain DCRaw?

I have the micro 4/3 version of the Olympus 9-18mm zoom and before it I had the regular 4/3 version. I have seen the Panasonic 7-14 in real life for five minutes only.

I'm happy with the micro 9-18. It is half a notch "worse" than the regular 9-18. Judging from images I have seen the Panny 7-14 is clearly better than my lens. But the 9.18 takes standard filters and is "good enough" for my use of a super wide angle lens.

As I have followed the Olympus SLR forums out there for years and the micro forums since Nov 2008 I feel pretty safe saying the a general vote between the available Super WA ooms would end like this:

Olympus 7-14 (reg 4/3)wins, quite close followed by the Panny 7-14 and then there is a small jump to the Olympus regular 4/3 9-18 close and finally followed by the micro Zuiko 9-18. That would include every sort of aberration, different levels of bragging rights and further Internet opinions one can find. I'm pretty sure about the order here but one should remember the difference from one lens to the next one is small indeed.
 

Tesselator

New member
Checking the lens for uncorrected LaCA... isn't that as easy as take the image in raw format and open it using Raw Therapee or any other converter not supporting the auto correction feature? Maybe Raw Therapee doesn't support the camera as of yet? Plain DCRaw?

I have the micro 4/3 version of the Olympus 9-18mm zoom and before it I had the regular 4/3 version. I have seen the Panasonic 7-14 in real life for five minutes only.

I'm happy with the micro 9-18. It is half a notch "worse" than the regular 9-18. Judging from images I have seen the Panny 7-14 is clearly better than my lens. But the 9.18 takes standard filters and is "good enough" for my use of a super wide angle lens.

As I have followed the Olympus SLR forums out there for years and the micro forums since Nov 2008 I feel pretty safe saying the a general vote between the available Super WA ooms would end like this:

Olympus 7-14 (reg 4/3)wins, quite close followed by the Panny 7-14 and then there is a small jump to the Olympus regular 4/3 9-18 close and finally followed by the micro Zuiko 9-18. That would include every sort of aberration, different levels of bragging rights and further Internet opinions one can find. I'm pretty sure about the order here but one should remember the difference from one lens to the next one is small indeed.
Good to know, thanks! On the correction issue I don't know for certain but I believe this is a preprocessing in-camera operation that takes place before any file (RAW or JPeg) is written. The correction AFAIK is applied to the image before it becomes a RAW or JPeg file. So if that's correct we would need to test the lens on a camera body that offers no such correction at all.
 

Terry

New member
Good to know, thanks! On the correction issue I don't know for certain but I believe this is a preprocessing in-camera operation that takes place before any file (RAW or JPeg) is written. The correction AFAIK is applied to the image before it becomes a RAW or JPeg file. So if that's correct we would need to test the lens on a camera body that offers no such correction at all.
No this is not completely correct. The raw files include instructions for the correction of CA and distortion. The RAW processor can either use or disregard that information. Now not all raw files are the same. Oly RAW files only include distortion information and not CA info. Panasonic RAW files include both. In addition that correction information is coming from the lens and not the camera. So, using an Oly lens on a Panasonic camera you don't get correction for CA because the info isn't collected. Using a Panny lens on an Oly camera you don't get CA corrections because Oly tosses them out. Also not that Panny more fully corrects distortion than Oly who at least on the regular kit lens left a little bit in to match the 4/3 counterpart.

Adobe built the capability into ACR very early on. Then about 2 years ago the DNG standard was changed to be able to capture this information. Aperture took a longer time to support. Some other RAW development programs have said, we aren't going to make the corrections.

So, it is possible to see uncorrected files if you use the right RAW developer. Here is more info:

http://www.dpreview.com/reviews/PanasonicGF1/page19.asp

http://www.dpreview.com/reviews/panasonicdmcgh1/page17.asp

Here is the 7-14mm lens on the Oly camera that does not correct for CA

http://www.dpreview.com/lensreviews/panasonic_7-14_4_o20/page4.asp
 

Tesselator

New member
Thanks Terry,

That doesn't look "terrible". Not great but not terrible anyway. Too bad that's DPR tho... They've been known to fudge, omit, and cater somewhat in the past. I'll assume these don't fall into hat category tho. :)
 

Terry

New member
Thanks Terry,

That doesn't look "terrible". Not great but not terrible anyway. Too bad that's DPR tho... They've been known to fudge, omit, and cater somewhat in the past. I'll assume these don't fall into hat category tho. :)
Those were the links easiest to find. This was widely discussed when M4/3 was new on the market and some RAW processors weren't equipped to deal with it.
 

Jonas

Active member
Good to know, thanks! On the correction issue I don't know for certain but I believe this is a preprocessing in-camera operation (...)
What a lack of faith... But I checked my post and noticed I put a question mark after my first sentence, so OK. :)

My oldest G1 is from November 2008 and I followed all those discussions about the in-camera corrections, and about the very big DNG files we got in the start, and... Then there is always this small possibility they changed something between the G1 and the GH2. In this case I don't think anything changed and thinking about it it is hard to see how the raw data itself should be corrected on the fly.

Cheers,

/Jonas
 

Tesselator

New member
Well, there's actually quite a lot of "preprocessing" that goes into a RAW. A RAW file is not just a sensor dump like some think. ;) Or so I've been told by those who say they know. They were convincing, I believe them. :)
 

Jonas

Active member
Well, there's actually quite a lot of "preprocessing" that goes into a RAW. A RAW file is not just a sensor dump like some think. ;) Or so I've been told by those who say they know. They were convincing, I believe them. :)
I like to think of the raw (not RAW) files as sensor dumps. At the same time I'm positive that is wrong, at least wrong from some points of view. To my understanding one can adjust the way the hardware works on some cameras and thus make the raw file depending on more than the plain exposure settings.

There may very well be more on the topic. Do you have any sources or links?

Cheers,

Jonas
 

Jorgen Udvang

Subscriber Member
If the RAW files were sensor dumps, all files from the same sensor, regardless of camera brand, should look the same and open with the same RAW converter settings. But they are not the same, so some processing is obviously going on. This is logical; all camera manufacturers want to give us what looks like "imaging according to them", even in RAW. Giving us pure sensor dumps would give us a situation where the lens manufacturer, the software houses and Sony decided how the output looks, at least for those using Sony sensors. And the software programmers wouldn't even need to talk with Nikon to know the "inner secrets" of their cameras. Sony would know what they needed to know.

No, the camera guys need their own secret formula, so that we can have that yellow Nikon look and the Olympus blue skies :ROTFL:
 

ustein

Contributing Editor
>On the correction issue I don't know for certain but I believe this is a preprocessing in-camera operation

It is in camera for JPEGs but not for Raw.
 

Jonas

Active member
If the RAW files were sensor dumps, all files from the same sensor, regardless of camera brand, should look the same and open with the same RAW converter settings. But they are not the same, so some processing is obviously going on. (...)
Ah, I'm not sure you are right.
I think I "know" Panasonic and Olympus uses different colors on the bayer overlay. That way everything is changed also if the raw files are "sensor dumps". Or one may say the sensors aren't the same.

Another thing which may make some (not you) users think things are different is that most raw converters apply the in-camera JPG settings (fully or partly) when opening the file in the converter.

So, to me there isn't any obvious processing going on. I know, now that i have written that somebody will tell me... ;)

But I'm willing to learn. Do you have any other arguments for pre-raw processing I would like to learn about it.

Don't forget the Canon orange, or red... :)

Cheers,

/Jonas
 

ustein

Contributing Editor
>Do you have any other arguments for pre-raw processing I would like to learn about it.

In few cases the Raws maybe tweaked for noise. At least it is rumored.
 

Jonas

Active member
>Do you have any other arguments for pre-raw processing I would like to learn about it.

In few cases the Raws maybe tweaked for noise. At least it is rumored.
I have been trying to find out about that. To my understanding the whole question, or issue perhaps, is down to noise reduction features that are based on hardware functions.

There was a rumor about Canon sensors and raw noise reduction. I couldn't find any reliable information telling me anything but this being about on-sensor hardware noise reduction circuit. I don't think about that as software processed raw files.

Then we have Sony and their FF cameras where there is some on-board noise reduction going on (not that one can see it in their high ISO images...). Again, as I understand it it is about on-board noise reduction circuits.

I'm also not at all sure about how there could be any software based noise reduction made but sometimes my brain isn't that flexible. Maybe it can be done, or maybe it is done. Maybe somebody knows about this?

regards,

Jonas
 
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