PDA

View Full Version : 70-300 cons


Scapula Memory
21st July 2008, 02:30 PM
I am thinking about getting the 70-300 and planning to use it for aircraft photography. So reading around the reviews which are generally very good I came across this one. Have a read of this, would like to discuss the cons and whether this is correct? What do you guys out there make of this? I will try and find the link again and post here.

Pros: This is one very good lens. This lens has the equivalent FIELD OF VIEW, not focal length (very big difference) of a 600 mm lens on a 35mm camera. The 2x crop factor is nice but this will NEVER fully replicate the image of a 600mm f5.6 on a 35mm camera make no mistake about this. I found the auto focus to be quite fast, I like it! The lens isn't that heavy so it's VERY good for bird photography. I like the AF/MF switch. The image quality is about the same as the 150mm ""kit"" lens but still, this kitten (as opposed to puppy) is a VERY fun lens to use! This thing has some gorillla reach. This lens is summed up with one word, ""unique"".
Cons: Believe it or not, the object in an image is exactly the same size as it would be if you used a 300mm lens on a 35mm camera. The Olympus DSLR's sensor is half the size so the angle of view is narrower than the same lens on a 35mm camera making it appear to be magnified but alas, it is not. It's like taking a picture with a 300mm lens on a 35mm camera and ""cropping"" the edges of the picture by 50% and expanding what's left over of the picture to fill the area that has been cropped out. The object in the image will just appear to be twice a large if you took the same picture with this lens! When I first found this out I was quite angry because of the ignorant wording used by 4/3rds supporters like ""600mm focal length equivalent"" is BS! When focusing from a close object to a far one, prepare yourself for some loud death noise from the motor. DOF is a lot larger as well with 4/3rds format. Some see this as an advantage, I on the other hand do not. No Nice blurry backgrounds @ F/5.6...
Other Thoughts: Do not fool yourself with Zuiko lenses! They are not nor will they ever be 2x the listed focal length. But also keep in mind that Zuiko glass is among the finest made right now if not the finest. The real advantage of the best Zuiko glass is that the F/2.8 lenses can be effectively used with 1.4 and 2.0 teleconverters without the loss of too much light by virtue of their insane brightness. I love my Zuiko 200mm F2.8/F3.5 so much I could spank babies with it.

Naughty Nigel
21st July 2008, 04:06 PM
Methinks this guy doesn't really know what he is talking about. Would I be right in thinking that he is an American?:(

He is right that a focal length is a focal length; sensor size cannot alter that. But sensor size is crucial to the magnification of an image when captured. Of course the image is cropped. All cameras crop images, otherwise they would suffer from chronic vignetteing problems and dark corners.

As an example, I personally use a medium format film camera quite regularly. The focal lengths required when shooting 6 x 4.5 cm images are about 1.6 x greater than for 35 mm (for the same angle of view), which itself requires focal lengths double that of the Four Thirds system.

If this gentleman were correct, a 50 mm lens would give me the same angle of view on any camera that I chose to use it on. We all know that it won’t. A 50 mm lens on my E1 is a short telephoto. A 50 mm lens on my Mamiya 645 (if there were such a thing) would give an angle of view slightly wider than a 35 mm lens on a 35 mm camera.

theMusicMan
21st July 2008, 06:36 PM
Right - I have read this sort of waffle many times on other forums, he does have a point, but it is not all negative. There are positives and negatives... here goes with my explanation...

Some people suggest that smaller sensor means lower quality images. Yes, to an extent I agree, but there's also a trade off with the larger sensor - and that's the effective focal length.

I appreciate that if a lens has a FL of 500mm, it has a FL of 500mm regardless on which camera it is placed on. However, if this same lens is placed on different cameras with the same number of sensor pixels [say 10MP] (but a different sensor size): then on a x2 crop factor camera the image is effectively magnified.

The image on the larger sensor camera has a larger field of view than the image on the camera with the smaller sensor... however, the image taken by the camera with the smaller sensor still covers 10MP, and if one then resizes/crops the image taken by the camera with the larger sensor to appear the same as the image taken with the camera with the larger sensor, the same image will comprise much fewer pixels.

So... which is best...? I'd say the image with the larger number of pixels i.e. smaller sensor. This is especially true for longer range FL's.

In summary: for the same image field of view; on smaller sensor camera the image is composed of 10MP, whereas on a larger sensor camera the same image field of view is composed of significantly fewer MP's and thus for longer length lenses the Oly 4/3 system is a distinct advantage - notwithstanding the light weight of the lenses.

Zuiko
21st July 2008, 07:20 PM
This guy is proof that a little knowledge is dangerous. He is partially right in that the focal length doesn't change on Four Thirds and that the extra magnification is achieved through a smaller image being recorded on the sensor. He claims this is misleading but what did he expect? You can't change the laws of Physics!

He is just plain wrong about D.O.F. What he overlooks is that regardless of the focal length and aperture, on any lens there is only one point of absolute sharp focus. The zone of focus in front of and behind this point that appears to be sharp isn't really, it just appears so to our eyes when viewing a print of a certain size at normal viewing distances.

This is based on the principle that a point of light recorded on film or sensor gradually becomes bigger the more out of focus it is, becoming a circle rather than a point. Now there is quite a bit of leeway before our eyes are capable of resolving it as a circle rather than a point so the deception of being in focus is achieved. Those circles grow larger less quickly at small apertures than at large apertures, hence a wide angle has more DOF at a given f-stop than a telephoto simply because the physical "hole" formed from the iris blades is smaller.

The traditional standard for acceptable DOF is what appears to be sharp on a 10 x 8 inch print at normall viewing distances. Enlarge that print much bigger or look much closer at just a part of it and the illusion of sharp focus in all but the actual point of true focus will rapidly disappear.

Now take the example of a picture taken on a 300mm lens on a 35mm film camera and enlarged to 10 x 8. Beside it put a picture taken with the same lens on a 4/3 sensor, also enlarged to 10 x 8. Because the image from the lens is already cropped you are actually looking closer than you would normally do at a section of a 20 x16 print and those circles of confussion in front of and behind the true point of focus will look distinctly more fuzzy, or out of focus.

Thus you have your 600mm telephoto effect with a 300mm lens! - Almost.........

It is true that smaller formats inherently have a little extra DOF notwithstanding taking into account the factors I've outlined above, but nothing like this guy apparently is suggesting!

Invicta
21st July 2008, 07:59 PM
This guy is proof that a little knowledge is dangerous. He is partially right in that the focal length doesn't change on Four Thirds and that the extra magnification is achieved through a smaller image being recorded on the sensor. He claims this is misleading but what did he expect? You can't change the laws of Physics!

He is just plain wrong about D.O.F. What he overlooks is that regardless of the focal length and aperture, on any lens there is only one point of absolute sharp focus. The zone of focus in front of and behind this point that appears to be sharp isn't really, it just appears so to our eyes when viewing a print of a certain size at normal viewing distances.

This is based on the principle that a point of light recorded on film or sensor gradually becomes bigger the more out of focus it is, becoming a circle rather than a point. Now there is quite a bit of leeway before our eyes are capable of resolving it as a circle rather than a point so the deception of being in focus is achieved. Thoe circles grow larger less quickly at small apertures than at large apertures, hence a wide angle has more DOF at a given f-stop than a telephoto simply because the physical "hole" formed from the iris blades is smaller.

The traditional standard for acceptable DOF is what appears to be sharp on a 10 x 8 inch print at normall viewing distances. Enlarge that print much bigger or look much closer at just a part of it and the illusion of sharp focus in all but the actual point of true focus will rapidly disappear.

Now take the example of a picture taken on a 300mm lens on a 35mm film camera and enlarged to 10 x 8. Beside it put a picture taken with the same lens on a 4/3 sensor, also enlarged to 10 x 8. Because the image from the lens is already cropped you are actually looking closer than you would normally do at a section of a 20 x16 print and those circles of confussion in front of and behind the true point of focus will loof distinctly more fuzzy, or out of focus.

Thus you have your 600mm telephoto effect with a 300mm lens!

I am not sure if I am reading this right but the DOF will vary with sensor size if all other variables: focal length, focused distance, aperture are the same.

Hence sensors like APS-C and four-thirds have greater DOF compared to 35mm when all the other variables are constant.

This is helpful for when you need good DOF e.g. landscapes and not so good to isolate a subject with shallow DOF.

Naughty Nigel
21st July 2008, 08:55 PM
Right - I have read this sort of waffle many times on other forums, he does have a point, but it is not all negative. There are positives and negatives... here goes with my explanation...

Some people suggest that smaller sensor means lower quality images. Yes, to an extent I agree, but there's also a trade off with the larger sensor - and that's the effective focal length.

I appreciate that if a lens has a FL of 500mm, it has a FL of 500mm regardless on which camera it is placed on. However, if this same lens is placed on different cameras with the same number of sensor pixels [say 10MP] (but a different sensor size): then on a x2 crop factor camera the image is effectively magnified.

The image on the larger sensor camera has a larger field of view than the image on the camera with the smaller sensor... however, the image taken by the camera with the smaller sensor still covers 10MP, and if one then resizes/crops the image taken by the camera with the larger sensor to appear the same as the image taken with the camera with the larger sensor, the same image will comprise much fewer pixels.

So... which is best...? I'd say the image with the larger number of pixels i.e. smaller sensor. This is especially true for longer range FL's.

In summary: for the same image field of view; on smaller sensor camera the image is composed of 10MP, whereas on a larger sensor camera the same image field of view is composed of significantly fewer MP's and thus for longer length lenses the Oly 4/3 system is a distinct advantage - notwithstanding the light weight of the lenses.

But that was not quite what he was saying. TBH, I am not entirely sure what he was saying; except that Olympus' claims of doubling the effective focal length on Four Thirds system cameras were a lie, and that (somehow) a 300 mm lens on an E System camera could never be the same as a 600 mm lens on a 35 mm camera.

He did not specifically mention image quality, although we have to accept that smaller pixels can never be quite as 'clean' as bigger ones.

All in all, I would agree with Zuiko that this guy proves beyond reasonable doubt that 'a little knowledge can be dangerous'!*yes

gno
21st July 2008, 09:02 PM
I will try and find the link again and post here.


Hi John,

I think this may be what you were looking for.

http://www.newegg.com/Product/Product.aspx?Item=N82E16830998143

Regards

Gavin

250swb
21st July 2008, 09:04 PM
Olympus make no 'claims', they are facts and the guy quoted is talking the sort of utter drivel contrived from half truths and lack of any real knowledge about photography. He is also wrong about the 70-300mm being fast focusing, it isn't.

Steve

Graham_of_Rainham
21st July 2008, 10:01 PM
I am thinking about getting the 70-300 and planning to use it for aircraft photography.

I got one a couple of weeks ago and it is brilliant. It produces excellent results, or should I say I do using it. It is much more versatile than I expected and can be used in all manner of situations.

while this is no great picture, it was the very first shot taken with the 70-300 from within my conservatory, through double glaseing covered in rain on a really dull day. Hand held at 300mm. *yes

http://e-group.uk.net/gallery/data/500/P7021805_1.jpg (http://e-group.uk.net/gallery/showphoto.php/photo/7028)

I also took it to my nephews 4th birthday party and was chasing him all over the garden (harder than tracking the Red Arrows, I can assure you)

I'll also add that I got it brand new for £178 off ebay so I'm even more delighted :D

My suggestion would be to get one and if you don't like it sell it (bet you don't):cool:

*chr

Zuiko
22nd July 2008, 10:12 AM
I am not sure if I am reading this right but the DOF will vary with sensor size if all other variables: focal length, focused distance, aperture are the same.

Hence sensors like APS-C and four-thirds have greater DOF compared to 35mm when all the other variables are constant.

This is helpful for when you need good DOF e.g. landscapes and not so good to isolate a subject with shallow DOF.

A 300m lens on Four Thirds will have much less depth of field than a 300m lens on the 35mm film format. However, the depth of field will not be quite as narrow as a 600mm lens on 35mm film.

This phenomenon is not exclusive to the comparison between Four Thirds and 35mm film, it applies to comparisons between any formats of different sizes. For example, let's compare 35mm film to 6x7 Medium Format. Here, the crop factor is approximately x2, the same as between 35mm and Four Thirds. Therefore a 100mm standard lens on 6x7 equates to a 50mm standard lens on 35mm. Fit a 100mm lens to the 35mm camera and it becomes a telephoto lens, equivalent to 200mm on 6x7.

Now that 100mm lens has far less DOF at any given aperture than the 100mm lens on 6x7. However, the DOF is not quite as narrow as the 200mm lens on 6x7.

Scapula Memory
22nd July 2008, 10:14 AM
Interesting replies. Thanks. It did not put me off getting one as mentioned in another thread but what this guy was saying did not seem to stack up.

Naughty Nigel
22nd July 2008, 10:28 AM
A 300m lens on Four Thirds will have much less depth of field than a 300m lens on the 35mm film format. However, the depth of field will not be quite as narrow as a 600mm lens on 35mm film.

This phenomenon is not exclusive to the comparison between Four Thirds and 35mm film, it applies to comparisons between any formats of different sizes. For example, let's compare 35mm film to 6x7 Medium Format. Here, the crop factor is approximately x2, the same as between 35mm and Four Thirds. Therefore a 100mm standard lens on 6x7 equates to a 50mm standard lens on 35mm. Fit a 100mm lens to the 35mm camera and it becomes a telephoto lens, equivalent to 200mm on 6x7.

Now that 100mm lens has far less DOF at any given aperture than the 100mm lens on 6x7. However, the DOF is not quite as narrow as the 200mm lens on 6x7.


I am not sure that is quite right.

A 300 mm lens will have exactly the same depth of field regardless of which format it is used on. Even Olympus cannot change the laws of physics.;) However, as the resultant image is magnified more on a Four Thirds camera, any loss of focus is more noticable than it would be if using the same focal length on larger formats.

Where the Olympus system 'benefits' is that focal lengths are half that of 35 mm cameras, so when using a 'standard' lens we are actually working at 25 mm focal length, with its much greater depth of field - although as I said above, the image is magnified more, so any loss of focus is more noticable.

The end result is that we 'enjoy' greater depth of field, but 'suffer' increased sensor noise.

Compact cameras provide a much more extreme example of what I am saying. They use very short focal lengths, and tiny sensors. Compact cameras provide incredible depth of field (even when compared with the Four Thirds format), but their sensors are extremely noisy.

Ian
23rd July 2008, 11:40 AM
I hope I can clear up some misunderstandings concerning focal length, sensor size and depth of field.

DOF (distance that is in sharp focus), the shorter the focal length, the more depth of field you will get at a given focal length and aperture. This relates to the physical size of the aperture, or hole inside the lens that lets the light through. If you shorten the focal length, but retain the brightness of the transmitted light, the aperture size reduces, and so depth of field increases. A Four Thirds camera requires a lns of half the focal length of a 135 format camera to see the same field of view, so the depth of field on Four Thirds will always be deeper than a 135 format camera with the same focal length lens and aperture. But it's NOT true that you can't get great bokeh (defocussed blur) with Four Thirds - even at f/5.6 on a 70-300, you can achieve excellent result by being closer to the subject.

Focal length and sensor size, it's true that the image circle of a Four Thirds lens has half the diameter of a lens designed for a 135 format 'full frame'. But actually, it's more sensible to say that the diagonal of a four thirds sensor is half that of a lens designed for 135 format film frame or sensor size. So, yes, a Four Thirds frame is effectively cropping a smaller area than a 135 frame, but a 135 frame is cropping a smaller area than a medium format frame. So, it's all relative. Anyway, the view 'seen' by the lens and projected out of the back onto the sensor is actually cropped by the lens designer to achieve the design aims of that optic in relation to the sensor or frame size. This is one reason why you need to be careful when using legacy 135 format lenses as they project a lot of un-needed light in to the mirror box, which could be reflected onto the sensor causing problems during the exposure. But it's perfectly reasonable to say that a Four Thirds lens has the same field of view as a 135 format lens of the double the focal length.

Hope that helps,

Ian

Invicta
23rd July 2008, 01:24 PM
Bokeh is certainly do-able with a four-thirds camera, I quite like this:

http://e-group.uk.net/gallery/data/623/foxglove2.jpg (http://e-group.uk.net/gallery/showphoto.php/photo/5999)

taken at f/4.0

Personally I like the extra depth of field given by APS-C / four-thirds sized sensors, makes it easy to get Ansel Adams's Group f/64 effects. :)

blu-by-u
25th July 2008, 01:31 AM
1/2 truths or not, I like this 600mm lens. Here is one of a Russian plane at the max of this puny lens..

http://farm3.static.flickr.com/2177/2543266365_c78c49498e.jpg (http://farm3.static.flickr.com/2177/2543266365_c78c49498e_b.jpg)

http://farm4.static.flickr.com/3010/2544159376_1ce48521e1.jpg (http://farm4.static.flickr.com/3010/2544159376_c8b5cf694a_o.jpg)

and this is just as the plane reached the end of it's up to tail spin down..
http://farm4.static.flickr.com/3104/2544093430_db5f0670dd.jpg (http://farm4.static.flickr.com/3104/2544093430_bb84c93b03_o.jpg)

One thing is, I am using a E-330 with the lens and trying to AF follow it is really difficult. The lens tends to focus the entire range!!!. I wonder is it's any different on the E-3.

Zuiko
25th July 2008, 02:51 AM
QUOTE Ian;20732]I hope I can clear up some misunderstandings concerning focal length, sensor size and depth of field.

DOF (distance that is in sharp focus), the shorter the focal length, the more depth of field you will get at a given focal length and aperture. This relates to the physical size of the aperture, or hole inside the lens that lets the light through. If you shorten the focal length, but retain the brightness of the transmitted light, the aperture size reduces, and so depth of field increases.

Agreed, but as we are talking about a zone of apparent rather than absolute sharp focus, don't we also have to take enlargement of the image necessary to produce a print of a certain size (traditionally 10x8) into account as this is part of the equation when calculating the maximum permissible circle of confusion for any given format?

A Four Thirds camera requires a lns of half the focal length of a 135 format camera to see the same field of view, so the depth of field on Four Thirds will always be deeper than a 135 format camera with the same focal length lens and aperture.

I'm really not sure about this, Ian (forgive me if I stand to be corrected) but my understanding is that if a greater degree of enlargement is necessary from a Four Thirds image than from a 135 image to produce the same size print then, because the circles of light at the inner and outer limits of the zone of acceptable sharpness on the Four Thirds image start to exceed the maximum permissible diameter, the DOF on the Four Thirds image is effectively reduced. Now, this doesn't totally negate the increase in apparent sharpness gained as a result of the physically smaller aperture for a given amount of light on a shorter lens so the truth lies somewhere in between. Thus, a 300mm lens on Four Thirds (600mm equivalent) will have greater DOF than a 600mm lens on 135 but less DOF than a 300mm lens on 135

But it's NOT true that you can't get great bokeh (defocussed blur) with Four Thirds - even at f/5.6 on a 70-300, you can achieve excellent result by being closer to the subject.

Focal length and sensor size, it's true that the image circle of a Four Thirds lens has half the diameter of a lens designed for a 135 format 'full frame'. But actually, it's more sensible to say that the diagonal of a four thirds sensor is half that of a lens designed for 135 format film frame or sensor size. So, yes, a Four Thirds frame is effectively cropping a smaller area than a 135 frame, but a 135 frame is cropping a smaller area than a medium format frame. So, it's all relative. Anyway, the view 'seen' by the lens and projected out of the back onto the sensor is actually cropped by the lens designer to achieve the design aims of that optic in relation to the sensor or frame size. This is one reason why you need to be careful when using legacy 135 format lenses as they project a lot of un-needed light in to the mirror box, which could be reflected onto the sensor causing problems during the exposure. But it's perfectly reasonable to say that a Four Thirds lens has the same field of view as a 135 format lens of the double the focal length.

Hope that helps,

QUOTE Ian

I apologise if I've got this wrong, but many years ago I spent considerable time researching this subject in order to get the best out of both my 135 and Medium Format prime lenses for landscapes. (I was after maximum, rather than minimum DOF!)

Cheers, (and isn't my signature line true! :o)

Imageryone
11th December 2008, 04:32 PM
Both my E-1 and E300 have constant autofocus, does the E-330 not have this wonderful feature?

Sorry, misses a few threads, this goes back a while.