Jml9905 wrote:.

Up until now and for the last year I have been using a Canon Xt withthe Canon 70-300mm IS + a kenko 1.4x extender. Often I feel I needmore reach and I've started looking at the various Sigma's zoomsthat go up to 500mm, particularly the 50-500. I need something that.

The Bigma is a popular choice..

Can be used without a tripod, therefore some kind of imagestabilization either in lens or in body is needed. Unfortunately theCanon 500mm IS lens is out of my budget. The 100-400 IS zoom is analternative, but I feel going from 300mm to 400mm is not enough. IfI'm going to spend money I would rather go from 300mm to 500mm.Therefore the necessity for a camera that has in body imagestabilization..

Whether the in-body image stabilization will be sufficient compared to, say, a tripod may be a question worth looking into. Your exposure times, focal lengths, steadiness, and need for sharpness will determine this..

I take it a monopod, shoulder stock,or similar alternatives are also not options?.

Now *everything else being equal* (and I'm sure they are not), isthere not an advantage in choosing the Olympus e-510 over say thePentax K10? Both offer in body image shake reduction, but the e-510has a 2x focal length multiplier while the pentax has a 1.5x. A 500mmon the e-510 would have the reach that a 1000m has on a FF, while onthe K10 it would have a reach of 750mm. Big difference. Correct?.

Yes, for the K10; sort of, for the E-510. I say 'sort of', because the aspect ratio is different. The 1000mm figure would be accurate for the diameter of the imaging circle, if memory serves, but you get a 4:3 rectangle within that circle..

Therefore is there not an advantage in using a 2.x body for that kindof photography? Both the k10 and the e-510 have a 10mp sensor. Somesay that the smaller sensor of the Oly is more noisy, but for outdoorbird photography super high iso is usually not needed. Is there someother factor that would negate the Oly 2x advantage? Focus speed andaccuracy? Metering?.

Well, something you might want to keep in mind is that the narrower FOV will magnify the effects of any shake; therefore, for the same basic lens (ex. the Bigma) used under the same circumstances, this will place a correspondingly higher demand on the E-510's stabilization system. I am not yet aware of methodical comparisons using super-telephoto lenses..

The E-510 seems to be a pretty fine instrument, and if I weren't weird about wanting a body I could take unprotected into rain, or interested in seeing what AF system Olympus has planned for the E-1's successor, I'd likely be considering purchasing one...

Jml9905 wrote:.

I am thinking about getting a second camera dedicated uniquely tobird's photography..

Up until now and for the last year I have been using a Canon Xt withthe Canon 70-300mm IS + a kenko 1.4x extender. Often I feel I needmore reach and I've started looking at the various Sigma's zoomsthat go up to 500mm, particularly the 50-500. I need something thatcan be used without a tripod, therefore some kind of imagestabilization either in lens or in body is needed. Unfortunately theCanon 500mm IS lens is out of my budget. The 100-400 IS zoom is analternative, but I feel going from 300mm to 400mm is not enough. IfI'm going to spend money I would rather go from 300mm to 500mm.Therefore the necessity for a camera that has in body imagestabilization..

Now *everything else being equal* (and I'm sure they are not), isthere not an advantage in choosing the Olympus e-510 over say thePentax K10? Both offer in body image shake reduction, but the e-510has a 2x focal length multiplier while the pentax has a 1.5x. A 500mmon the e-510 would have the reach that a 1000m has on a FF, while onthe K10 it would have a reach of 750mm. Big difference. Correct?Therefore is there not an advantage in using a 2.x body for that kindof photography? Both the k10 and the e-510 have a 10mp sensor. Somesay that the smaller sensor of the Oly is more noisy, but for outdoorbird photography super high iso is usually not needed. Is there someother factor that would negate the Oly 2x advantage? Focus speed andaccuracy? Metering?.

Hi.

I get confused on this reading various threads about it..

Its my understanding that a 300mm lens is a 300mm lens no matter if it is a 4/3 or aps or full frame. The field of view on a 4/3 would be that of a 600mm lens but the lens is still 300mm. Where the increased telephoto effect comes from is that if printing (say) at 8x10 this is a bigger enlargement using a smaller sensor than a larger one and therefore if the 2 are printed at the same size will seem that the 4/3 is a longer lens. Because the 4/3 size is good enough to handle enlargement at common sizes used, then for all intents and purposes it does make a difference and the same with aps over full frame. In each case though the larger the sensor the more it should handle enlargement or be allow it to be cropped to appear the same (as long as you have enough pixels).

I stand ready to be corrected..

Neil..

I have apentax *istD. it has a 1.5 multiplier. for zoos and animals I have the sigma 50-500mm with the 1.4 and 2.0 converters. with the 1.4 the setup is still completely full auto. with the 2.0 you loose auto focus. I get 1050mm using the 1.4 converter and 1500mm with the 2.0.

The lens is just too heavy for any real steadiness. the *istD is a 6mp dslr. I have had some great pics with bigma with and without the converters. I do not know how much farther you wish to go beyond a full auto 1050mm lens. that is the equiv to 21X gainst a normal view.

If you with to go there I would suggest some kind of telescope/spottingscope instead of a phtography telephoto..

On the subject of mutipliers/cropfactors. if you have a 300mm lens and 1.5 multiplier you get the equiv to 450mm in the viewfinder. as compared to say a canon 5d with a 450mm lens. the 2 images in the viewfinder will be the same. the difference is that the 450 on the 5d will have all that lens' OTHER characteristics, such as 450mm depth of field. while yours will have the 300mm depth of field, but visually it will look as though it is 450mm...

Your problem with the Olympus will be getting a clear enough view of your intended subject. If hand held and with body IS the image is going to dance around in the VF. The downside of the 2x crop here is that it makes for a smaller viewfinder which makes it even more difficult to see what you are doing..

I have seen a video of the 510E using live view. That looks promising as the image will be stabilised but holding a body and big lens away from your body will be quite difficult and will add to the shake partially negating the value of IS. Have you thought of using a monopod? That would help. Of course there may also be problems viewing the LCD in strong sunlight.Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

Neil holmes wrote:.

Hi.

I get confused on this reading various threads about it.Its my understanding that a 300mm lens is a 300mm lens no matter ifit is a 4/3 or aps or full frame..

Hi,.

The FoV of a lens won't change but the FoV _used_ by the camera will change depending on the camera used..

For comparisons it's best to ignore the field of view which is normally measured across the widest part (ie the diagonal) and look at the FoV side to side and up and down. You'll they all differ slightly, even when supposed to be the same. the trouble is that we say "35 mm film equivalent" and forget that that is just a rough rule of thumb. better still just look through the viewfinder: theory is all very well but....

Try this link:.

Http://photo.net/equipment/leica/digilux2/.

And scroll down to a paragraph headed "The Lens" and you'll see an excellent diagram comparing "28" and "24" mm coverage..

Regards, David..

Greetings folksjust wanted to bring to your attention a very similar thread running here.

Http://forums.dpreview.com/...ums/readflat.asp?forum=1022&thread=23866493.

Cheers.

Riley.

I like to think the bs can never be higher than the ah..

Neil holmes wrote:.

Hi Neil,.

The lens does not change if you use it on a FF or APS-C sized body. It is still a 300mm, but the camera changes. In one case the image will be bigger on the sensor of the FF body, while the image projected on the sensor of an APS-C body will be smaller. To get the same FOV on a FF body, (the same size image that is projected on the smaller sensor) you need a bigger lens on the FF, bigger by 1.5x - 1.6x..

Jml9905.

Hi.

I get confused on this reading various threads about it.Its my understanding that a 300mm lens is a 300mm lens no matter ifit is a 4/3 or aps or full frame. The field of view on a 4/3 wouldbe that of a 600mm lens but the lens is still 300mm. Where theincreased telephoto effect comes from is that if printing (say) at8x10 this is a bigger enlargement using a smaller sensor than alarger one and therefore if the 2 are printed at the same size willseem that the 4/3 is a longer lens. Because the 4/3 size is goodenough to handle enlargement at common sizes used, then for allintents and purposes it does make a difference and the same with apsover full frame. In each case though the larger the sensor themore it should handle enlargement or be allow it to be cropped toappear the same (as long as you have enough pixels).

I stand ready to be corrected..

Neil..

Hi All,.

Thanks for answering..

What I will do is try and use a monopod, see if I can get use to it. Most of the pictures I take though are taken simply walking with the camera in my hand and you have to be quick to take a picture. A birds flies in, lands on a branch, sits still for only a few seconds, hops around a bit and flies off. My experience with tripods is that by the time I'm set up, it's gone..

I will definitively try the Bigma before buying as like some of you have said, it might be too big to hold steady and/or the FOV too narrow and difficult to get the subject in the viewfinder..

I have held the e-510 in store yesterday. It feels good. The viewfinder is surprisingly not that bad compared to my 350d, not smaller but more squarish. Unfortunately the liveview IMHO is not useable outdoor in bright sunlight..

If I had the money I'd buy them all, Canon, Nikon, Pentax and Olympus and Hassie. .

Jml9905..

In view of what you said I suggest you look at the Olympus 35 to 100 mm* zoom which is f/2 all the way. Perfect for what you want though how you'd do it and use live preview escapes meat the moment..

Regards, David.

* That's 70 to 200 in 35 mm film terms: not too long for handheld a lot of the time...

Jml9905 wrote:.

Neil holmes wrote:.

Hi Neil,.

The lens does not change if you use it on a FF or APS-C sized body.It is still a 300mm, but the camera changes. In one case the imagewill be bigger on the sensor of the FF body, while the imageprojected on the sensor of an APS-C body will be smaller. To get thesame FOV on a FF body, (the same size image that is projected on thesmaller sensor) you need a bigger lens on the FF, bigger by 1.5x -1.6x..

Jml9905.

Hi.

But isn't it still just a crop of what it would be 35mm? If you crop a photo from a 300mm lens on the larger sensor camera you can get the same fov as (say)400mm or 600mm or whatever on a smaller sensor. Wouldn't that mean that it is because the smaller sensors are good enough at common print sizes that the telephoto effect results, because the larger sensor pics are not enlarged anywhere near as much?.

Neil..

Hi,.

I'm not exactly an expert, maybe somebody can explain it better, but here goes. If I screw up nobody get mad. .

I don't hink it has anything to do with print size or the telephoto effect. You could imagine a really bad <1mega pixel cropped sensor. The field of view would still be 1.6x that of a full frame sensor. You certainly would not be able to get a decent print size from the files of that type of sensor but a 100mm lens on that camera would still give you the field of view that a 160mm does on a FF. Maybe you are confusing print size with mega pixel and/or sensor photo-pixel density?.

Telephoto effect is something different. If I'm not mistaken, it refers to the change in perspective that long telephoto lenses cause. Objects that are far from each other appear close to one another, the telephoto "stacking" effect..

Jml9905.

Jml9905 wrote:.

Neil holmes wrote:.

Hi Neil,.

The lens does not change if you use it on a FF or APS-C sized body.It is still a 300mm, but the camera changes. In one case the imagewill be bigger on the sensor of the FF body, while the imageprojected on the sensor of an APS-C body will be smaller. To get thesame FOV on a FF body, (the same size image that is projected on thesmaller sensor) you need a bigger lens on the FF, bigger by 1.5x -1.6x..

Jml9905.

Hi.

But isn't it still just a crop of what it would be 35mm? If youcrop a photo from a 300mm lens on the larger sensor camera you canget the same fov as (say)400mm or 600mm or whatever on a smallersensor. Wouldn't that mean that it is because the smaller sensorsare good enough at common print sizes that the telephoto effectresults, because the larger sensor pics are not enlarged anywherenear as much?.

Neil..

You are right the pic would appear to be the same if you shot with a 160mm(150mm) and shot from 100ft with a 35mm or ff, then cropped to give you the c sensor view. then shot from 100ft with a c sensor. they would appear the same BUT if you compared whjat was in focus in both shots, they would be different. the dof is coming from the lens itself not the crop factor...

Gary,.

On the smaller sensor does one need to stop down the aperture by the crop factor multiplier to get approximately the same DOF as on a FF sensor?.

FF sensor: 100mm f4 lens = N amount of DOF1.5 Sensor: 150mm f4 lens = 1.5 times N amount of DOF.

Therefore stop down by 1.5 stop to get roughly the same DOF as on the FF..

Or does one need to use a different mutiplier?.

Jml.

GaryDeM wrote:.

You are right the pic would appear to be the same if you shot with a160mm(150mm) and shot from 100ft with a 35mm or ff, then cropped togive you the c sensor view. then shot from 100ft with a c sensor.they would appear the same BUT if you compared whjat was in focus inboth shots, they would be different. the dof is coming from the lensitself not the crop factor...

Go to this web site-.

Http://www.dofmaster.com/dofjs.html.

And put some identical numbers in. if you use the canon 5d or idsmkII you have what is 35mm film dof..

What I did was compare it to my pentax *istD at the same fstop and distance with the same lens set in both. what I discovered is that very roughly 35mm or digital FF at f16.0 gives the same DOF as the *istD(1.5 crop) at f11.0..

This means that you are picking up dof when you go to cropped dslr. this makes even more sense when you conside how much dof a digicam has with their fingernail sized sensors..

This is also a help in the area of diffraction distorsion which on a 1.5/1.6 crop dslr kicks in at about f11.0. but as stated above f11.0 if giving the dof of film slr at f16.0. this means you can take you flower pics at f11.0 and still get substantial dof...

My experience shooting absurdly long focal lengths (in my case, the K100D with a 500mm reflex lens, a 1.5x teleconverter, and a 1.5x crop factor):.

1) 1000mm is about the longest lens you can hand-hold. Any longer, and either a small aperture means there isn't enough light for the fast shutter speeds you'll need, or a large aperture means the depth of field is too shallow to contain your subject..

2) Framing your subject isn't a problem. Yes, the image does dance around a bit, but not enough that you can't keep your subject in place..

3) Finding your subject in the first place is a problem: the field of view is only 2 degrees. A finder scope mounted to the flash hotshoe would be useful..

4) Big lenses are *heavy*. My Tamron 500mm with teleconveter weighs slightly less than two pounds, and it's still tiring to hold up for more than a few minutes...

Cool site, very informative. Thanks.

GaryDeM wrote:.

Go to this web site-.

Http://www.dofmaster.com/dofjs.html.

And put some identical numbers in. if you use the canon 5d or idsmkIIyou have what is 35mm film dof.what I did was compare it to my pentax *istD at the same fstop anddistance with the same lens set in both. what I discovered is thatvery roughly 35mm or digital FF at f16.0 gives the same DOF as the*istD(1.5 crop) at f11.0..

This means that you are picking up dof when you go to cropped dslr.this makes even more sense when you conside how much dof a digicamhas with their fingernail sized sensors..

This is also a help in the area of diffraction distorsion which on a1.5/1.6 crop dslr kicks in at about f11.0. but as stated above f11.0if giving the dof of film slr at f16.0. this means you can take youflower pics at f11.0 and still get substantial dof...