Welcome to the club.This is just Chromatic Aberration/Purple Fringing. Not so good lens..

Try to stop down to see if you may get rid of the CA/PF problem. Also the picture is blurry because of the shallow DOF.VictorBucuresti, Romaniahttp://s106.photobucket.com/albums/m268/victor_petcu/..

Baloo_buc wrote:.

Welcome to the club.This is just Chromatic Aberration/Purple Fringing. Not so good lens.Try to stop down to see if you may get rid of the CA/PF problem. Alsothe picture is blurry because of the shallow DOF..

Yes. At high shutter speed, which you chose to freeze subject movement, the auto exposure system likely needs the widest lens aperture ....just in order to let in enough light for correct exposure..

Sadly.......

Even the best lenses do not give of their best sharpness when used at open stop (maximum aperture). So, better to stop down 2 stops from maximum to improve lens quality and increase depth of field..

Then freeze subject movement by carefully picking the right moment to shoot......

..... and by increasing ISO, but only if absolutely necessary to get a sufficiently high shutter speed.Regards,Baz..

So if I understand correctly my problem with this is the exposer? As I said I am new to this level of photography and I need guiding with the telephoto stuff. I am not saying that I have deep pockets but if a new lens is what it takes then so be it. And by the way that pix was taken with a 300mm lens not a 200mm like I said to begin with..

Now I have taken close ups that turned out fantastic. I have a shot of a rose after rain that has dept of field and fantastic lighting...

99igor wrote:.

So if I understand correctly my problem with this is the exposer?.

Not quite. The problem is in the lens; it is showing chromatic aberration - but that can be minimised or eliminated by using a narrower aperture (if possible)..

It's not that you got the exposure wrong - it's that your exposure (aperture) was strecthing the limits of the lens. A better lens, at the same exposure, would not show the same CA..

I am not saying that I have deep pockets but ifa new lens is what it takes then so be it..

Don't move too quickly! There's no doubt that a better lens would improve the results but before you invest that much $ take some more photos and see how much of a problem this really if for you..

If it's spoiling lots of shots, despite your best efforts to choose the right exposure (to avoid stretching the limits of the lens) then of course go for it. If it's just an occasional thing, and the need to keep your exposures within the limits of the lens is not such a big deal, then you might prefer to spend your $ on other accessories..

Your call, but you shouldn't necessarily assume that a new lens is a "must" based on one experience..

I saw some terrible CA in a shot taken with my Nikon 18-200 the other day. It was also the first serious CA I had seen in over 5,000 photos talen with that lens. So I'm not rushing out to buy a new lens..

Now I have taken close ups that turned out fantastic. I have a shotof a rose after rain that has dept of field and fantastic lighting..

Probably because- the lens performs better at the shorter end of the zoom range- the aperture was narrower.

- the lighting was less severe (CA tends to show up more in brightly lit light coloured subjects, like your birds)..

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window..

Thank you arrowman. I plan on running back out to the same place today and trying to mess with some options. I also need to check the meta data and see what apretures those things were taken with..

I am learning, I hope...

This is purple fringing... Issue with lenses if there are major changes of contrast in an image... Can reduce by playing around with aperture/some other settings etc in some cases..

Some other alternative is to see if you can get a better background to shoot with lesser chances of purple fringing, do postprocessing etc....

Http://budding-nature-photographer.blogspot.com/..

In addition to the explanations already given, if you look again at the picture, imagine all the blue/purple fringing is gone. There is still a problem with the exposure..

The birds white feathers are examples of burnt-out highlights. There is a loss of detail in the feathers due to overexposure. If this were controlled better, by a somewhat darker exposure, the original problem, of fringing is also likely to be reduced, though not completely.Regards,Peter..

There is a photoshop plugin called 'PTlens' that can help to fix chomatic aberration: see.

Http://www.epaperpress.com/ptlens/.

- then click on the 'examples' link, and scroll down to the shot of a building which has chromatic aberration around all the white window frames. the sofware removal is pretty good..

As others have pointed out, the problem in your shot is worse because the white deathers of the birds are overexposed. Your automatic metering read the scene as a whole and came up with an exposure to suite the dark(er) background, which is correctly exposed at the cost of the detail in the birds' plumage. About 1 stop less exposure would have been about right. Hindsight is always easy of course (I'm brilliant at it). But with a little practice you will quickly recognise scenes where the main brightly lit subject is surrounded by a darker background (as here) which requires less exposure than the meter says; and one where the main subject is in shadow against a brighly lit background (sea, snow, sky) - these require more exposure than your auto meter suggests. Practice at dialling in exposure compensation in either direction with the little thumb wheel....

Best wishesMike..

Mike703 wrote:.

There is a photoshop plugin called 'PTlens' that can help to fixchomatic aberration: see.

Http://www.epaperpress.com/ptlens/.

I am happy to endorse the PTLens program. It is cheap, and very good indeed..

As others have pointed out, the problem in your shot is worse becausethe white deathers of the birds are overexposed..

Right again. .

Regards,Baz..

Well as it usually works out, I went back to the place where I shot those pictures yesterday and not an bird in sight. I even picked up a new tripod for the occasion. I will catch them again and try all the ideas I have here..

I will see if I cant duplicate the problem in my back yard as the distance I was away from the birds is about the same as my rear yard line..

And thanks for the link to the software. I might try it out later but first I need to get the picture better..

I do have one question though. Disclaimer - Remember I am new to Dslr photography..

When you say go down a stop ( or two), does that mean smaller aperture which would mean higher f# or a larger aperture..

Also I was shooting with auto ISO and the camera picked 100. Would messing with that help the situation?.

I understand that the f numbers go up as the aperture gets smaller. (Which makes no sense to this feeble mind.) :<)..

Tne number of stops (X) indicates the number of times you double or cut the light in half. The amount of light energy that can get through a lens is determined by the area of the lens opening times the exposure time..

Area is proportional to the square of the diameter of the lens, so to cut the area (and the amount of light that can get through it) by half, you have to cut the diameter of the lens by the square root of two, which is 1.414... to simplify the equation they write it as new len diameter = old diameter/f# where the f# = square root of 2 raised to the power of the number of times you want to cut the light in half..

The square root of two raised to the power of zero = 1 so that gives a series of f numbers f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22... where f/1 means the lens is wide open, (almost impossible to do in the real world, since you cut some light with the mounting and loose some to glass absorption so f1.2, or about 70% of the theoretical maximum, is about all that is practically feasable). That is where the f numbers come from..

Calling these doublings and halvings of exposure a "stop" just simplifies things to simple addition and subtraction. I.e. if your exposure calls for 1 second at f/5.6 you can get the same exposure by doubling the area of the lens opening (f/4) and halving the time (one stop up in aperture and one stop down in time)..

Though it is more complicated than this, you can sort of think of it like filling a bucket with a hose... assuming the water pressure is constant (which is sort of like the intensity of the light reflecting off your scene), if you get 2 gallons a minute through a 1" hose, and you have a 2 gallon bucket, it will take 1 minute to fill it up. If you stop the hose down 1 stop to 1"/1.4 or 0.7", you should get 1 gallon a minute (and would have to wait for 2 minutes for your bucket to fill up). Your ISO is sort of like the inverse measure of your bucket size (bigger number = smaller bucket).

Your color fringing is probably chromatic abberation, which should be noticable around high contrast objects... power lines against the sky for example.http://en.wikipedia.org/wiki/Chromatic_Abberation.

There are also APO (apochromatic) lenses. These are made with corrective lenses made from fluorite or exotic "ED" glass, which allow a careful designer to make lenses that are nearly free of CA. But, fluorite is expensive and hard to work with so these are generally quite expensive. Various types of "ED" glasses, that have optical properties similar to fluorite, were recently invented as a cheaper alternative. ED glass comes in different grades at different costs, and some designs are better than others, so just because a lens says it has ED glass doesn't automatically mean it is an APO. Some of the cheaper ones are only semi-APO, but are still usually better than ordinary achromatic lenses..

Higher f#s will reduce CA so stopping your lens down should help reduce that, though you eventually reach a point of diminishing returns (then you'll either need to buy a better lens or find a program that is good at color fringe removal)..

I do have one question though. Disclaimer - Remember I am new to Dslrphotography..

When you say go down a stop ( or two), does that mean smalleraperture which would mean higher f# or a larger aperture..

It means a bigger number, which is a smaller aperture. The f number is actually a measure of the size of the hole through which the light passes, divided by the focal length of the lens. So as the hole gets smaller the fractions get smaller: 1/2, 1/2.8, 1/4, 1/5.6 etc. It is the bottom number that is quoted, so a big umber (f16) means a very small hole (diameter 1/16 of the focal length of the lens)..

Lenses tend to perform at their poorest when wide open (maximum aperture, smallest number). SO if light permits it is always worth 'stopping down' a bit, i.e. choosing a smaller aperture (bigger number). if your lens has a maximum aperture of f/5.6 at 300mm, stop it down to f/8 or even f/11 and it's performnace will improve considerably. The downside of this is that you will need a longer shutter speed to compensate for the fact that the lens is letting in less light, which might result in a blurred image.

Also I was shooting with auto ISO and the camera picked 100. Wouldmessing with that help the situation?.

Yes. This is a measure of the sensitivity of the detector. 100 is usually the minimum. If you set it to 200 (twice as sensitive) you can take the same picture by letting in only half as much light, i.e. with a smaller aperture or faster shutter speed. There is a tiny penalty in terms of higher image noise, but that is much less significant than having blurred pictures because of camera shake with a slow shutter speed..

WIth you lens set at it's maximum zoom (300 mm) I'd suggest the following as a starting point:.

1. Set the camera to aperture priority, lens opening to f/8..

2. See what shutter speed that gives you. If there is enough light so that you can use a shutter speed of 1/500 sec or faster, you're good to go..

3. If you end up with a slower shutter speed (say, 1/250 sec) you run the risk of blurred pictures because the high magnification of the lens will maginify camera shake. So increase the ISO by a factor of two (from 100 to 200, or from 200 to 400) until the shutter speed becomes short enough..

You'll get the hang of it quickly enough! Just experiment....

Best wishes.

Mike..

99igor wrote:.

When you say go down a stop ( or two), does that mean smalleraperture which would mean higher f# or a larger aperture..

The usual terminology regarding the lens is "stopping down" and "opening up", or some thing like that. To "stop down the lens" or "stopping down the lens" means to make the hole in the lens smaller. As you gathered, that means using a larger f/number..

Also I was shooting with auto ISO and the camera picked 100. Wouldmessing with that help the situation?.

Yes, without going to extremes, where noise could become a problem. All things being equal, as you stop down the lens, the amount of light is reduced, so you need a slower shutter speed to compensate. In order to avoid using too slow a shorter speed, increase the ISO and the shutter speed will still be reasonably fast..

Finally, as I suggested previously, you may want to bias the exposure, setting the exposure compensation to minus 1 (roughly). That will result in a darker image, which will help with the white highlights.Hope this helps,Peter..

Sherwoodpete wrote:.

99igor wrote:.

When you say go down a stop ( or two), does that mean smalleraperture which would mean higher f# or a larger aperture..

The usual terminology regarding the lens is "stopping down" and"opening up", or some thing like that. To "stop down the lens" or"stopping down the lens" means to make the hole in the lens smaller.As you gathered, that means using a larger f/number..

Also I was shooting with auto ISO and the camera picked 100. Wouldmessing with that help the situation?.

Yes, without going to extremes, where noise could become a problem.All things being equal, as you stop down the lens, the amount oflight is reduced, so you need a slower shutter speed to compensate.In order to avoid using too slow a shorter speed, increase the ISOand the shutter speed will still be reasonably fast.Finally, as I suggested previously, you may want to bias theexposure, setting the exposure compensation to minus 1 (roughly).That will result in a darker image, which will help with the whitehighlights.Hope this helps,Peter.

P.s. Although I'm happy to use automatic exposure, I prefer to have control over ISO and usually set it to a fixed value. I tend to use the lowest possible for landscapes, as high as possible for indoor low-light work, and somewhere in between for other subjects, as I feel the need. That comes with experience...

You have an excellent camera. It offers you an "Hi200" ISO which should work quite well here. Select it, take a "spot metering" on the bird, put your thumb on the AE lock button (it is just in the right place, top right of the back of your camera), compose and shoot at the right time....

Should the background be too dark for your taste, try with "center weighted" metering, putting the bird in the center, never use "multi segment" or "automatic" on a scene like this, it generally ends up with overexposed light objects..

With time and experience you will probably end up using nearly always spot metering, making small adjustments with the AV +/- button. Don't rush, there is a learning curve with everything and every button... and every lens..

Train with the A mode, don't keep your lens wide open, close it by at least one f: stop, better two if the light allows you..

And check Fidda filters for purple fringe and colour aberration, they are free and not bad..

Also, shooting RAW will allow you a better control in the RAW processor software.Just passing by.....

.... but I do have just one small niggle with the information as presented.

Yuzuha wrote:.

The square root of two raised to the power of zero = 1 so that givesa series of f numbers f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11,f/16, f/22... where f/1 means the lens is wide open,.

Errr.. "f/1 is wide open?" .. Well, that's not exactly right..

(almostimpossible to do in the real world, since you cut some light with themounting and loose some to glass absorption so f1.2, or about 70% ofthe theoretical maximum, is about all that is practically feasable)..

F/1 lenses are perfectly possible, even if their Depth of Field is pretty minimal, and their full aperture performance less than wonderful. They are have been around for some time. Check out this Canon 7 camera from 1961.....

.... with a maximum aperture that's slightly WIDER than f/1....

.....a staggering f/0.95 ... in fact!!.

(on Ebay... if it is still up)....

Http://cgi.ebay.com/...temZ180142199813QQihZ008QQcategoryZ30027QQcmdZViewItem.

See what it can do here.....

Http://homepage.mac.com/jlw/photo/canon_on_rd1/.

FYI: Note how much better it does when the UV filter is taken off!!.

The widest lens I have ever owned was a Nikkor of f/1.2.. which was OK-ish at open stop... but I preferred my f/2 which cost less than 1/4 of the price!!Regards,Baz..

Thank you for all the answers. You people are a world of help. I am happy I was heading down the right track. Hopefully I will see those birds again soon and give these fixes a try..

Also I was wondering about that H200 iso setting. I had planned on giving that a try too..

Thanks again. I was told about this forum by a friend of mine in VA. He said the people here are very good resources and don't treat you like an idiot. He was right...

Barrie Davis wrote:.

.... with a maximum aperture that's slightly WIDER than f/1....

.....a staggering f/0.95 ... in fact!!.

Regards,Baz.

Well, low f#s used to be the marketing equivalent of higher megapixels so maybe that is a clever marketing by fiddling with the specifications since f/.95 would mean the image through the lens is actually brighter than looking through a hole and actually acting as an image intensifier..

Be interesting to see the optical design on that one. They have to be doing some intensification trick with an oversized front element concentrating the light onto a smaller primary objective to come up with a number less than one since it is impossible to get more out than you put in (fundamental law of physics and thermodynamics: Not only can you never win... you can't even break even!).

BTW, my favorite old lens was the Canon 50mm f/1.4 NFD...

That Hi200 setting is supposed to preserve more details in the highlights, and the Lo80 is supposed to preserve details in the low lights. Of course, all of that depends of available light.... You may want to go up to ISO800 or more to freeze the action sometimes! Only time and experience will tell you the right decision and the "workarounds".Happy shooting!Just passing by.....

Yuzuha wrote:.

Snip.....

....... f/.95 would mean the image through the lens isactually brighter than looking through a hole and actually acting asan image intensifier..

Huh? "Image intensifier" What are you talking about?.

Are you labouring under the impression that there is some kind of theoretical limit of f/1... and that anything wider than that is somehow a "cheat"??.

Be interesting to see the optical design on that one..

[It is more-or-less symmetrical.. like the Zeiss Planar... and a lot of other high performance lenses of more modest aperture.].

They have tobe doing some intensification trick with an oversized front elementconcentrating the light onto a smaller primary objective to come upwith a number less than one since it is impossible to get more outthan you put in.

No. You have got hold of the wrong end of a completely *different* stick..

You seems to be regarding f/1 (where aperture diameter equals f-length) as some kind of equivalent to 'Unity' in energy terms. Be assured it is no such thing, and no particular restraint exists in optical construction......

.... other than making the lens elements sufficiently well to assemble into sharp performers at the designed maximum aperture....

... and at a price that can be afforded.... [pretty much like any other lens, in fact.].

(fundamental law of physics and thermodynamics: Notonly can you never win... you can't even break even!).

Nope. Doesn't apply. Nothing special about f/1 as such, other than you don't see it very often..

Sorry.Regards,Baz..

Jpp wrote:.

That Hi200 setting is supposed to preserve more details in thehighlights, and the Lo80 is supposed to preserve details in the lowlights. Of course, all of that depends of available light.... You maywant to go up to ISO800 or more to freeze the action sometimes! Onlytime and experience will tell you the right decision and the"workarounds"..

As an additional point to jpp's high ISO comments above....

.... remember that high ISO noise(!)......

1) does not show AT ALL in highlight zones.. (like white birds).

2) and does not show VERY MUCH in midtones that have lots of macro detail to mask it... (like reed beds rendered sharply)..

Where digital noise shows, especially that which comes from the use of high ISOs, is where "grain" in films used to be seen most clearly........

... in large areas of featureless tone ..... like blue skies. Regards,Baz..

And that's why NeatImage (and others) has been invented... First class freeware too! Try it, and if you like it, buy it!Just passing by.....

Barrie Davis wrote:.

Are you labouring under the impression that there is some kind oftheoretical limit of f/1... and that anything wider than that issomehow a "cheat"??No. You have got hold of the wrong end of a completely *different*stick..

You seems to be regarding f/1 (where aperture diameter equalsf-length) as some kind of equivalent to 'Unity' in energy terms. Beassured it is no such thing, and no particular restraint exists inoptical construction.....Regards,Baz.

Hm, quite possible. Now that I think about it, you are correct. I was thinking telescope formulae where the focal length of the objective is longer than, or at most equal to, the diameter of the lens. On thinking about it, if the diameter is larger than the focal length, then you could indeed get f numbers less than one. I would think that would really enhance the effects any abberations though so any such lens would have to be made with extreme care to be any good, and probably cost a small fortune (which might be why they are so rare?)..

Yuzuha wrote:.

On thinking about it, if the diameter is larger than the focallength, then you could indeed get f numbers less than one..

Yes. All that has to be done is to take a standard element for a much larger lens, and grind it with much MORE curve on it..

Simple enough [!!!] except that it is MORE than difficult enough to do well. .

I wouldthink that would really enhance the effects any abberations though soany such lens would have to be made with extreme care to be any good,and probably cost a small fortune (which might be why they are sorare?).

Yes. Again you are right, although low dispersion glasses, which were not around in the 60s, and the advent of aspheric elements made by cheaper moulding techniques, would both make the super-wide-aperture type of lens cheaper and better; the new technologies have instead been used to make wider-ranged zooms. Regards,Baz..