Originally Posted by
EdN
loss of one stop,
Yes, but you lose lightly more than one stop with the 7D because you are cropping away light.
If you are using a lens like a 300 mm F2.8 lens, it still works at F2.8 on a 7D (with aview similar to a 480 mm lens). If you put a 1.4x on the lense for the 5D Mk II to get a similar view (420 mm), it is shooting at F4. If you already have a 5D Mk ii, a 7D does give you flexibility in your gear as a second body and something for longer shots, especially if you also want to use the 1.4x too - get up to 672 mm at F4.
Originally Posted by
EdN
some more chromatic abberation,
You will increase chromatic abbreation with a 7D also becuase you are throwing away lens resolution and magifying lens defects.
I believe chromatic abberation is a function of the quality of glass and the amount of glass that light has to travel through. You put less glass for light to travel through, including that of a 1.4x, the better off you are with your image. As far as throwing away lens resolution, the smaller pixels of the 7D gets you all the resolution you have in your lenses so it's important to use good glass. And if your glass isn't the best, you will see all those defects. Yes, you only use the center field of view of the lenses where the best quality of the image field is and you do throw out the corners, where the quality diminishes. If you also have a full frame body, you get to use it there.
Originally Posted by
EdN
loss of contrast depending on lighting and the shot.
You also loose contrast with the 7D. The lightingdoes not affect the actual contrast of the lens, it affects the picture.
Contrast is also a function of the quantity and quality of glass that light has to go through. A 1.4x extender adds to losing contrast by adding more glass for light to transmit. You probably lose contrast in the 7D with the smaller pixels for light collecting but without lots of testing, who's to know what's technically really less intrusive? My experience is that the more that I shoot with the 7D, the more impressed I am with the image quality. They sure did a nice job on the sensor. Knowing the limitations of the 7D, and using it in GOOD lighting conditions, I have no hesitation using it with a 1.4x extender and getting images as good as I would get using the same lens and the 1.4x on the 5D Mk II, only I get better close-ups when I need them.
Originally Posted by
EdN
still probably marginally better but in GOOD lighting,
Originally Posted by
EdN
the 7D's pictures are indistinguishable from the 5D Mk II's with the 1.4x.
It would be significantly better, and even better in low light because the 5D II has better dynamic range and color tones.
My experience is that in GOOD lighting, there is not that much difference. Yes, if you shoot in back-lit situations or with heavy shadows, the 5D Mk II is noticeably better. If you avoid those situations with the 7D, you can get great shots.
Originally Posted by
EdN
The best use of your gear would be to use the 7D with the 1.4x extender.
Im not talking about that, what I am talking about is the fact that a 7D has inferior reach than a 5D II. If that is the case then why not just crop and why make extenders? Either cropping is better or extenders are better, you can't have amixture of both. Thats why medium format isbetter than 35mm.
The original purpose of the thread was to give SafariMonkey and idea on what he could use on his trip. If he had a 7D, 5D Mk II, 1.4x, and a 300 mm lens on his trip, why won't he use the 7D with the 1.4x on the 300 mm lens to get a better shot of that lion in the distance, especially if there is good even lighting? What he would get would be a decent picture with more resolution than if he chose only to use the 5D Mk II, the 1.4x, and the lens and try to crop in post processing. If he does have to post process, he has more pixels to work with too.
Originally Posted by
EdN
My experience is that you better be prepared to practice holding your breath and holding still, even at high shutter speeds because any movement will result in loss of sharpness as the image gets "smeared" to adjacent pixels as the shutter is pressed.
That has nothing to with our conversation about reach, you need just as high of a shutter with a 1.6 or a FF.
You are right. This has nothing to do with reach but it is applicable for considering the "7D - whole package" as a body to take along for a safari. It's something I've noticed in my experience that I thought I'd share with SafariMonkey for his consideration of the pro's and con's of the 7D.
Originally Posted by
EdN
*gives you extra reach - with what you've got for glass
The 7D is just a lower quality extender, to say "make the most of your glass with a 7D" is equivallant to saying "make the most of your glass with a lesser quality 3rd party extender". It's the same thing.
I don't agree with you about the 7D being a "lower quality extender." As before, you have to consider the "whole package", the blazingly fast AF, the super accurate AF, the 8 fps, and even the 18 megapixel sensor. You also have to be aware of the limitations too. The image is softer, you lose shadow detail even at lower ISO's, you have to shoot at higher shutter speeds and hold still, and in average lighting conditions, your image quality will be lower than the 5D Mk II. If you take all this into account and can minimize these conditions, you will be rewarded with excellent results using the 7D. I won't hesitate using a 1.4x with it.
When I first purchased the 7D, I thought it would be an alternative to buying bigger glass, so in effect an extender like you say. In practice,my expectations were far surpassed as all the features of the 7D contributed to a great package that delivered fantastic pictures, in many respects equal in IQ to the 5D Mk II and in other shotssurpassing the 5D Mk II with the AF and 8 fps.
Back to the extender thing again. I only use Canon's 1.4x as most reviews of the 2x indicate too much loss of IQ. I've never used any third party extender either. The 1.4x is suppose to only degrade an image only slightly while giving more reach at a loss of one stop. If you want to think of a 7D as an "extender", why would you not want to use an extender that gives you 2.24x more focal length with the loss of one stop, but also provides killer AF, 8 fps, and really good IQ if you watch the lighting. To boot, it is more affordable than getting a bigger lens for the 5D MkII, a lot more light weight thanbig glass, more portable in the field, and gives you a second body.
There are advantages with the 7D which make it very suitible for wildlife and birds, but I am talking about reach only. I would like to say that the 7D would not look terrible, Nate uses it and his shots are great! But if Canon made the 7D with a full-frame sensor it would be significantly better.
As before, the intent of the thread was to give SafariMonkey advice on a second body. That was the intent of my comments - the suitability of a 7D for his safari. As far as reach goes, it's part of the features that come with the 7D. In terms of arguing the merits of reach as it pertains to FF vs 1.6x crop, I can only comment on what my experiences are. I am interested in the topic but who really as access to all the technical data on optical design and sensor design to really give a conclusive answer? I don't and can't but I can comment on my experiences of FF and 1.6x crop in the field.
I too have also pondered a 7D with a full frame sensor. To me, that would be the 5D Mk II with the 7D AF. I wondered why they never did that in the first place. That would have been an awesome package. Instead, I ending up getting a 7D to supplement the 5D Mk II. Now that I have a 7D, I do enjoy the extra reach it gives me. I have portability and don't have to pack around a really big white lens (although I would really want one sometimes though).
I do not want to get anybody mad here, just a civalized debate.
John.
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