More on lens "correction"

In many cases, the "corrective" features of a manufacturers software will work very well. They aren't the complete answer, and anyone who has used an ultra-wide lens will know that it has its own unique character, and you won't get the same result as a tilt/shift lens without a lot of work.

However, if you are interested in what is actually happening to a file and exactly what kinds of correction are being employed, then its useful to download yourself a copy of a dcraw programme (they are open source and usually free, though a donation always helps them develop) and see what a "raw" raw file looks like. Apart from anything else its the closest you can get to seeing what the sensor is actually recording, without any "interference" from the manufacturers software.

This is not something that I would recommend as a matter of course, and you may try it and decide that it's much easier to stick with the native software or ACR etc. The point that I am trying to make here, is that when you do use a dcraw programme, you are then in a much better position to decide if how the software processes the file "improves" it and whether it corrects it in way that works that you. I think it doesn't do much, Others think it does.

I spend my life taking photographs, and editing them. I'm also constantly testing and seeing what does what. Its my job, and I allocate time for that. If you haven't got that time, would prefer to use it doing something else, or quite simply don't care that much, then you won't be missing much. I invest a lot of time in photographing architecture, because it partly pays my mortgage, and wide angles are an important part of that, so I'm keen to know what they are doing and its of interest to me to see if I can get a more useful file out of a software programme that doesn't "correct" a file in the way that the manufacturer of the camera and lens thinks it should be "corrected"

In some cases I can get a better result from dcraw and the photoshop transform tools, in some cases I can't and in some cases it doesn't matter. It all depends on what I want to do and what kind of image I'm working with and, most importantly, to what use its going to be put to.

If you haven't read it already the Dpreview article which has the heading "What if I don't want to use the manufacturer's RAW converter?" at http://www.dpreview.com/...a-distorted-view-in-camera-distortion-correction/2 is an excellent (short!) read, and gives a nice overview of the issue. There's also a companion piece to this at:- http://www.dpreview.com/articles/5653763779/a-distorted-view-in-camera-distortion-correction/1

Perhaps it might be useful to end with an example and some process, to illustrate what I mean.

 

 Panasonic GH2 7-14mm lens. Tripod. 1/10th. sec. f/11 ISO 160 

The top picture is a jpg.("corrected") straight out of the camera. For the bottom one, I processed it in Rawker (dcraw) and produced a 16-bit tiff which I opened in Photoshop. I then edited the file, using the transform tools. You will notice that in the bottom right there is more of the sofa visible. dcraw does give you this "extra" bit which is very helpful for the transform process.

Not perfect, but the client was happy, and it shows what an alternative can give.

Nikon D5100 - Part 8 - 35mm f/1.8 lens.

Its a shame there aren't more lenses like this from Nikon. Small fast primes for their APS-C sensor cameras. The 35mm f/1.8 is a decent lens and provides a good fast "standard" lens for low light.

To give an idea of the relative size of the D5100 fitted with this lens, here are some pictures of it next to a Panasonic GH2 fitted with the 7-14mm zoom.

As you can see its not that much bigger. The body is also only 100g heavier than the GH2, so its very light and small for a DSLR.

Here it is next to a Leica M9.

No Mirrors, No SLR's.

Back in 2009 I published this.

http://soundimageplus.blogspot.com/2009/10/g-series-pro.html

A few weeks ago my camera shelf looked like this:-

As of today it looks like this:-

I posted my Sony a850 off, finally, to its new owner a few hours ago and for the first time in my serious photographic life I have no (D)SLR.

It was a close run thing. Right up to the last moment I almost bottled out and kept the Sony. What if Vogue phone up? How can I be a professional photographer any more? I don't have a big camera. Thoughts like this kept running through my head. The fact that I can be at my local Jessops with a credit card in less than 15 minutes, didn't seem to register!

It does feel strange, I will admit that. I definitely have the sense that something is missing. So what do I have left.

Leica M9 50mm Zeiss T* Planar. One lens, no dust spots, amazing quality.

Fuji X100. Great quality. Wonderful Viewfinder. My low light camera.

Panasonic GH2 and Olympus E-PL2. Panasonic 7-14mm Zoom. Olympus 14-150mm Zoom. Panasonic 20mm f/1.7, Panasonic Leica 45mm f/2.8 Macro. My "Pro" outfit. 

Its what I've wanted to do for a long time, and I've decided its time to try it. The X100 filled in so many pieces of my "gear jigsaw". A small, light camera thats great in low light was something I've been looking for for ages. It's not perfect, but it works for me.

There are (were) a couple of DSLR's I might (have) been interested in. The Sigma SD-1 was one but at £6200 I think I'll pass! The other is the Sony A77. I'd like to think I will go with whats above but there's still that little nagging voice that says "You're not a real photographer without a DSLR" I'll see if it persists or fades away.

Interesting times ahead!

Property Pictures and HDR

Yesterday I was shooting some interiors with a Panasonic GH2 and a 7-14mm zoom. One of the problems is handling the dynamic range in these shots, particularly since m4/3 isn't the best at this. Normally I shoot a range of exposures and cut and paste bits from each, or mask off areas and selectively darken or lighten. This is how the top three shots were done.

I did try Photoshop HDR as well. Here are the three shots I used. Bracketed at -2, 0 and +2.

This is an HDR version of those three shots, with some Photoshop adjustment.

Its OK, and I presume I could get it better with practice or even using different software. However I'm not sure it improves what I do already.

Panasonic 7-14mm Zoom

With a property shoot coming up, which generally provides a great opportunity for stock library shots, I have got myself a Panasonic 7-14mm zoom again. Since I will be working in fairly restricted space I need the widest I can get.

The 7-14mm is an amazing lens, and gives a fairly unique "world view" at 7mm.

I didn't use my last one much however and eventually sold it. This one may go the same route, but while its around it will certainly produce dramatic pictures.

Olympus E-PL1

This is my third E-PL1. On the two previous occasions, I bought it as part of a kit, kept the lens and sold the camera on. I generally took a few pictures, noted the performance was virtually identical to what else I had and that was that. On both occasions this has enabled me to get the lens I wanted at a very good price. Having bought this one plus lens from the Olympus refurbished site, I was planning to do the same. However a couple of days ago I wanted a second camera with a longer lens to accompany the Fuji X100, so I decided to take the EPL1 plus Panasonic 45mm f2.8 macro.




Using it for a prolonged period of time however I found I liked the interface much better than the E-P1 and E-P2. I found it much easier to change settings and I found I preferred the menu layout, which while still not perfect as far as I'm concerned, was much less frustrating. I was using the view screen only as I hadn't got the VF-2 viewfinder, and in bright sunlight, wearing dark glasses, it was almost impossible to see, but overall it was an encouraging experience.









Looking at the images on the screen after returning home, I was again impressed. Shot at ISO 100 they were every bit as sharp as the Fuji X100 pictures I took at the same time. (For some reason the 45mm Panasonic Leica lens always seems to perform really well with Olympus cameras.)

I decided to investigate this further and ordered a viewfinder, which arrived overnight from Amazon and I took it out yesterday with Panasonic 7-14mm and Olympus 14-150mm lenses.






Again it performed very well, I found it a pleasure to use, the viewfinder was excellent, as I've found before and the images were nice and sharp. I really should have used the previous two I had more! I've decided to try an E-PL2 now, as it apparently has better build quality.


Overall a good discovery (particularly at the price I bought it for) and one thats somewhat restored my faith in Olympus, which is no bad thing.

m4/3 Native Lenses - Part 1

Lenses for m4/3 cameras - Short opinions about the current m4/3 lenses is a piece by Thom Hogan at:- http://bythom.com/m43lenses.htm 


Lots of people have weighed in with opinions as to how right he is and have come out with their own lists. Not wishing to left out on something as much fun as that!  Here's mine.


Like Mr. Hogan I haven't used them all. The Panasonic 14mm f2.8 pancake, 100-300mm, 8mm fisheye and 3-D lens are missing from the list.





STANDARD ZOOMS

Panasonic 14-45mm f3.5-5.6
The lens that with the G1 started m4/3 as a system. This is an excellent lens for a kit zoom. Designed with Leica it really set the standard for the quality, lightweight lenses that followed. I used mine an awful lot. Because of the way that m4/3 cameras tend to be sold as kits, I think I've had 3 of these. I've usually sold the spare ones on ebay, which as they attracted good prices made the camera cheaper. It seems Panasonic aren't offering these as kit lenses anymore, so if you've got one it might be a good idea to hang onto it.

Panasonic 14-42mm f3.5-5.6 
Panasonics replacement to the 14-45mm. Cheaper, lighter and smaller. This lens often gets a bad press and while its not particularly good wide open its pretty sharp at f5.6 - f11. It really comes into its own as a video lens. It has the same silent continuous focusing as the 14-140mm and produces excellent footage. Some people rate it below the 14-45mm, but from my experiences with it (limited as I haven't had it long) I think its very similar in terms of performance. Well worth keeping if you buy one as part of a kit.

Olympus 14-42mm f/3.5-5.6 
Again because of camera/lens kits I've had a few of these. I've always liked this lens. It often got compared unfavourably to the Panasonic 14-45mm and I always thought that was unfair. Its an extending lens and has no stabilisation built in. I think its better than it gets credit for and very much on a par with the Panasonic standard zooms.

WIDE ZOOMS

Panasonic 7-14mm f/4.0 
Very wide, very expensive. Very light for what it is. Its a sharp lens and produces amazing images, particularly at 7mm. I did however have some issues with my copy. Firstly it produced a lot of CA and fringing and secondly that big exposed bulbous lens and fragile construction always worried me with concerns about possible damage. If you like ultra-wide then its a great lens, though there's a fair amount of distortion. Fixed f4 aperture is very useful.

Olympus 9-18mm f/4-5.6
I think this a great lens. I've spent a long time looking for a good wide-angle that produces results like a standard prime and this is the closest I've found. It produces very sharp results, even wide open and at f8-f11 its very very good indeed. I like the size, its tiny, and I don't feel so concerned about damaging it. Its very good for CA and fringing as well. Whether you choose this over the Panasonic 7-14mm depends on how important those 2mm are. They do make a significant difference with lenses at these focal lengths and there's no denying that the 7mm on a GH1 or 2 at the 16:9 ratio using the full width of the sensor is impressively wide. I do however prefer the Olympus, for my uses.

PANCAKES

Olympus 17mm f/2.8
10/10 for style, 5/10 for content. Somewhat of a disappointment. It does look great but mine performed pretty poorly with lots of CA and fringing. Mine was reasonably sharp but needed stopping down to f8 or so to get that. It doesn't compare well with the lens immediately below.

Panasonic 20mm f/1.7
I loved this lens the first day I tried it and I still do. I said then it produced the best results wide-open I'd ever seen and it was one of the best lenses I'd ever used on any system. I still stand by that. This is the lens that really demonstrates what m4/3 can do. It's wonderfully sharp, at all apertures, and its performance at f1.7 sets the benchmark for other lenses. I'm far from alone in praising it's virtues and if you were wondering if it lives up to the hype - It does!

Dynamic Range

In a recent forum discussion on the Panasonic GH2 samples, which look really good, someone rightly pointed out the concerns about dynamic range. This has always been a problem with m4/3 in particular and digital sensors in general. 


From time to time we do some property photography, for estate agent websites and brochures. Interiors are very hard and test a cameras dynamic range to the limit. 


Below are two examples from a bracketed sequence, taken with a Panasonic GH1 and a 7-14mm wide angle zoom.





The bottom shot is getting close to what is required for the interior, but the window is completely blown out and unrecoverable. So to get a satisfactory result we had to use the top version and lighten the dark areas both in camera raw and photoshop. We prefer this to using HDR as, for obvious reasons, a natural look is required. By working with the file we eventually came up with this.





The "look" is right. Nice light bright interior and some detail in the window. Some of the exterior is burnt out but it works quite nicely. However there is a large amount of noise generated by the lightening and for the final clients version we would do more work, getting rid of that. Probably by replacing areas within the room with sections cut and pasted from other lighter shots. The section on the left with the shelf is particularly nasty and would have to be substituted.


With a suitable budget and the time to do it, a better result could be obtained by using some flash heads, but the circumstances dictated that this had to be done quite quickly and cheaply!!


So some problems with m4/3, but shots like this are very difficult with any camera. They were difficult with film and they are difficult with larger sensors also.


Heres another from the same shoot. This is the camera jpg taken with a Canon 5D MK II and 20mm lens.





The range is slightly less than the first shot, as there is more light and less dark areas.


The final result after Photoshop work looked like this.





Again an OK result with a light interior and detail outdoors. However there is still a burnt out sky, and a considerable amount of noise which would have to be eliminated.


Interior shots like this are incredibly difficult. You only have to look at the problems movie makers have with situations like this. Unless they use banks of interior lights, they will suffer from the same problems as above. In many cases, it just has to be accepted. Currently we have no film nor camera sensor that comes close to what our eyes can cope with. Someone in a recent forum expressed the concern that manufacturers obsession with higher resolutions has led to the problems of dynamic range being largely ignored. He rightly made the point that by now we should have something better than we have. Even the very best film or sensor camera/lens combinations are a long way off recording what we see with our eyes. We can come up with solutions because we have to, but it would make things a lot easier if we didn't. I'm afraid in-camera or software HDR isn't the answer. Can be useful for static subjects, though we are not convinced by what we have seen, but completely useless when one shot is all you get. 


In terms of m4/3, yes dynamic range is more of a problem than with larger sensors, though we've not seen any great improvement from the APS-C sensors we've used, and in the really difficult situations other solutions have to be found. They have to found for full-frame sensors as well as m4/3, so the notion that somehow these larger sensors solve all your DR problems is somewhat inaccurate. They don't. They may be marginally better, but it is marginal and we need somebody to come up with a satisfactory solution. However it still seems a low priority for camera manufacturers.


Finally, going back to the GH2 samples, they did seem to be no worse in terms of DR than the GH1. The high ISO performance looked excellent, with samples at ISO 3200 and 6400 looking very similar to the Canon 550D, which is high praise indeed. The upsizing of the sensor seems to have worked very well, as would have been expected. Panasonic wouldn't have done it if they knew it was going to be inferior to what they have already. If the samples translate to real world performance then they really have come up with something special, and deserve to be regarded as at the forefront of current sensor technology. A little more concern about DR wouldn't go unappreciated however.


D & A

Panasonic 7-14 lens corrections.

Of all the m4/3 lenses available the 7-14mm wide-angle zoom from Panasonic is perhaps the one that most "corrections" are done to using the in-camera functions.


Using Rawker to process the raw files and comparing the resulting jpgs with the camera created jpgs gave some interesting results and shows some of the things that are going on.





In this first comparison the Rawker file is slightly bigger, and reveals more. It has slight vignetting. The colours are very similar and both files exhibit burnt out highlights in the white cloud. Overall colour is pretty similar.





The second comparison shows that at default sharpening settings, both are pretty similar. On the originals the Rawker conversion is very slightly sharper though not by much.





I put this comparison together to check out the CA and fringing. But as you can see something else has happened. The two areas aren't the same size though they contain the same information. There is some warping or perspective correction that has been applied to the in camera jpg. In terms of CA and fringing the camera jpg is slightly better, but both are pretty bad.





Intrigued by the previous result I overlapped the two images, "locking" them on the bench - i.e. the area within the red rectangle. As you can see, quite a lot of correction has gone on.


So this gives some idea as to what Panasonic are doing in-camera to "correct" what the lens is recording. It really isn't a huge amount and the Rawker processed file is perfectly fine. There's nothing there that I couldn't do myself in Photoshop. Its also a no worse result than I've obtained from many lenses. I've had £1000 Canon lenses that were worse than this. 


The idea that Panasonic are making massive software corrections to compensate for a not very good lens, isn't really apparent here. Its interesting to see what goes on though. In terms of this particular lens, I generally use Photoshop Camera Raw, and that seems to produce the best result. The main problem I see with the 7-14 is the fringing, which although not unusual in very wide angle lenses is nonetheless something I could really do without.


D