# Chromatic Aberration...



## Multipla Mick (Feb 5, 2006)

So far I've been reasonably happy with the G7 and the photos it produces, but on Tuesday I photographed a house and did two sets up the pole, one with the wide angle converter thing, and one without. Initially, I was quite pleased with the results, but on examining the photos more closely, there is epic colour fringing in most of the pics








Not happy at all. I'm pretty new to all this digital camera stuff, and for that job used the camera in programme mode, but I gather this is more to do with lenses and the pixel pitch of the camera... now, not wanting to be a poor workman who always blames his tools, is there something I can do to avoid this in the set up of the camera, or rectify it afterwards in Elements 5?
I've been looking at the EOS 450D and a Sigma 10-20 for sticking up the pole in the name of better quality results (hopefully, and that G7 wide converter isn't going to be the best quality...) and a bit more flexibility (plus I fancy a DSLR for hobby stuff too), but it would be a steep learning curve I imagine. Would the 450D be less prone to this fringing? One thing that bothers me about some of this is that I've read/heard that cramming ever more pixels into compacts actually can have a detrimental effect on results, and here's the 450D boasting 12 mega wotsnames... so I wonder if that will be going down the same route, albeit it'll have a bigger sensor in the first place (I think...  )

Hmmmm... I need to get on top of this digital lark more thoroughly methinks...


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## percymon (Jun 27, 2007)

The sensor size on the EOS 450 is the same physical size as the one i had in my 6Mp EOS300D and my current 8.2Mp EOS30d. As they cram more into the same postage stamp sized area the pixels have to become smaller and eventually quality will/must suffer. 

The pixel race is all marketting spin, getting people to upgrade cameras all the time - when i bought my 30d i looked at the 5D, but was talked out of it by the sales guy saying ' unless you are printing above A3 or earnign money from the camera, save your money !'

Nice to have soem sound advice rather than taking money off me !!

However, the quality of the image reaching the sensor on a dSLR will be better than that of a compact - it has to be as the glass of the lens can be ground more accurately when its a bigger physical size. The wide angle adaptor you are using will not be the best quality as you already know.

The sigma 10-20mm is a £300 lense - has decent sized optics and gets excellent results with very little aberation (huge improvement over what you have). Just remember the 1.6x factor on the DSLR so its really 16-32 in old 35mm film speak. Its an excellent lens and will work very well on the 450. I would also think about buying a runout 400 model, its not much different to the new 450 and cashback offers make them good buys at present.

I'd also advise you buy the Canon kit with the plastic stcok 18-55mm lense - its not fantastic quality, but for the difference in price over buying just the body, its a handy addition for general picture taking - its also very light so easily carryable in a coat pocket


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## -ROM- (Feb 23, 2007)

Chromatic aberration is mostly down to the quality of the lens and how it focusses the light that hit the photosites (pixels) on your sensor. It occurs more at short focal lengths than long focal lengths.

If i were you i'd be spending my money on a cheap SLR body like the 350d which has more than enough pixels for your needs, and more on the lens, for example:

http://www.warehouseexpress.com/product/default.aspx?sku=1005844

Rather than a newer body and a third party lense.


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## Multipla Mick (Feb 5, 2006)

Thanks chaps, good advice. But for using up the pole, live view and remote capture make life easier, hence the interest in the 450D. The 400D and 350D can be used up a pole, but it involves all sorts of shenanigans in viewing what the camera sees and controlling it from the ground. The 40D is a better quality camera, and has less megapixels, and live view, but is pretty heavy and right on the weight limit for the mast, body only, once you've added the weight of the pan/tilt unit.
The kit lens with the 450D is now an IS lens apparently, and so I've read, is slightly better in quality generally over the previous version, and thanks to a link on talk Photography, the 450D can be had with the kit lens for £508 from Dixons of all people, using a discount code, so that is quite a drop on the RRP of £599 body only, and I imagine Dixons sell UK sourced stock, so it is rather tempting. The Sigma gets good reviews and is a decent price, so I'd get one of those happily (always loved wide angle photos on my old Olympus, and that was 28mm...) but I'll have a hunt around and see how it stacks up against the Canon equivalent, as you say, money on decent lenses is always well spent.
This is the first time the colour fringing has been really noticeable on the G7, and it really spoils what otherwise were some decent enough photos, even without the wide converter, so I'm tempted by the 450D for sure. Like anyone, I want the quality of the final product to be as good as I can get it, so I think the G7 will be relegated to back up duties. I need to get out and get more hobby photography done too, but the G7 doesn't inspire me in that way much for some strange reason, must be me, as it's a good camera really.
Thanks again, (you do get very prompt replies on here  ) :thumb:


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## -ROM- (Feb 23, 2007)

Multipla Mick said:


> Thanks chaps, good advice. But for using up the pole, live view and remote capture make life easier, hence the interest in the 450D. The 400D and 350D can be used up a pole, but it involves all sorts of shenanigans in viewing what the camera sees and controlling it from the ground. The 40D is a better quality camera, and has less megapixels, and live view, but is pretty heavy and right on the weight limit for the mast, body only, once you've added the weight of the pan/tilt unit.
> The kit lens with the 450D is now an IS lens apparently, and so I've read, is slightly better in quality generally over the previous version, and thanks to a link on talk Photography, the 450D can be had with the kit lens for £508 from Dixons of all people, using a discount code, so that is quite a drop on the RRP of £599 body only, and I imagine Dixons sell UK sourced stock, so it is rather tempting. The Sigma gets good reviews and is a decent price, so I'd get one of those happily (always loved wide angle photos on my old Olympus, and that was 28mm...) but I'll have a hunt around and see how it stacks up against the Canon equivalent, as you say, money on decent lenses is always well spent.
> This is the first time the colour fringing has been really noticeable on the G7, and it really spoils what otherwise were some decent enough photos, even without the wide converter, so I'm tempted by the 450D for sure. Like anyone, I want the quality of the final product to be as good as I can get it, so I think the G7 will be relegated to back up duties. I need to get out and get more hobby photography done too, but the G7 doesn't inspire me in that way much for some strange reason, must be me, as it's a good camera really.
> Thanks again, (you do get very prompt replies on here  ) :thumb:


I got an idea why not buy a transit van with a cherry picker, i'm sure the electricity companeis sell them for a song after they've done with them!


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## Multipla Mick (Feb 5, 2006)

rmorgan84 said:


> I got an idea why not buy a transit van with a cherry picker, i'm sure the electricity companeis sell them for a song after they've done with them!


I did think of that! There are companies both here and the US that use them, a lot quicker and easier too.... access to some places would be hindered, but it's something I did consider...


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## Deanoecosse (Mar 15, 2007)

Why are you using the camera up a pole Mick, are you up to your old peeping Tom antics at the local nurses accomodation again? Tut tut.

ps, got any pics?


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## Multipla Mick (Feb 5, 2006)

Deanoecosse said:


> Why are you using the camera up a pole Mick, are you up to your old peeping Tom antics at the local nurses accomodation again? Tut tut.
> 
> ps, got any pics?


:lol: Didn't you know, it's my new business venture www.pervingpixels.com


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## -ROM- (Feb 23, 2007)

Multipla Mick said:


> I did think of that! There are companies both here and the US that use them, a lot quicker and easier too.... access to some places would be hindered, but it's something I did consider...


Yeah i suppose if you were targeting commercial customers, such as industrial estates, shopping centres, etc it would be great. For residential though, as you say, the access would present problems!


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## Multipla Mick (Feb 5, 2006)

Todays lesson is, if in doubt... shut your eyes and go for it, waiting and wondering will cost you more...

The 450D was £528 on Dixon's site earlier this week, with a £20 discount code available making it £508, but it must've been a mistake as it's now showing as £580, more in line with everyone else







Wish I'd just gone ahead and ordered one a couple of days ago now....

Approach with caution, I am now, really rather grumpy...


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## JasonRS (Aug 8, 2006)

Not sure if you can fix it in Elements, but in Photoshop "Camera RAW" has lens correction which can help address chromatic aberration.

Of course, this does assume you're shooting RAW.


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## Multipla Mick (Feb 5, 2006)

JasonRS said:


> Not sure if you can fix it in Elements, but in Photoshop "Camera RAW" has lens correction which can help address chromatic aberration.
> 
> Of course, this does assume you're shooting RAW.


Thanks for that, the G7 doesn't do RAW (it's successor after only a few months, the G9 does though  ) but RAW is something else that could be of benefit...


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