70-200 f4 IS to 2.8 IS MK1....or other?

I currently have the 70-200 f4 IS and love this lens. Over the past few months I have shot indoor soccer and indoor gymnastics. Fortunately, my 7D handles the high ISO pretty well, however, the f4 was obviously a little too slow for both situations (the need to stop action and keep the exposure high enough).

I have though about ditching the f4 IS and getting a second hand f2.8 IS MK1. I do have a couple of concerns:

1. Is the extra stop that the 2.8 offers going to make a big enough difference to warrant the change?
2. Am I going to lose any IQ by changing to the 2.8 IS? I've read mixed comments on this board about the the difference in IQ between the f4 IS and the 2.8 IS MK1.

I know that some may say that 2.8 is not fast enough for indoor sports and the prime would be the answer. But, one prime may not be the answer. The challenge is that I usually have to shoot from the bleachers....and the distance to the action is not the same in each venue. Nothing worse than sitting there with a nice f2 prime and you are the wrong distance for the prime that you have. Guess that is what I like about having a zoom.

So, what would you do in this situation? I am open to recommendations. Thanks.

Get the sigma OS. It will save you money, has AF that will blow you away, image quality on 7d that is as good at f/4 as your current 70-200, and very nearly as good at f/2.8, and it costs less than the canon IS mk I (used).

Any other recommendations?

I dont have a definitive answer for you, but a couple of thoughts. Before you leap, use one of your primes at f 2.8 to make sure thats going to be enough to merit the change, some places its not. The f4IS is sharper than the 2.8IS mkI, but its still a great lens.

Thanks Gonzo. The only prime I have right now is the 50 1.8. It's good for portaits but not for sport.....AF is not great and the FL is too shorts to shoot from the bleachers.

Thanks for the Sigma advice arentol. Tough to move from a weather sealed lens to non-weather sealed though.

I would save my pennies and get the mkII. I rarely shoot my mkI at f/2.8 because the sharpness isn't in the region that I like. I'm pretty much always at f/4. I like knowing that the extra stop of light is there if I need it, and sometimes I do, but I don't think it's enough of a reason if you already have the f/4 lens. You'll enjoy having the mkII I think, but you'll regret getting just the mkI.

As far as the f/4 being sharper, I'm not sure that's true. If it is, it's negligible. The main difference that I see is that at f/4, there is way less vignetting on the f/2.8 lens. You can see the difference here. Mouse over the image to switch back and forth between the two.

DL Photo wrote in post #12076348
Thanks Gonzo. The only prime I have right now is the 50 1.8. It's good for portaits but not for sport.....AF is not great and the FL is too shorts to shoot from the bleachers.

Thanks for the Sigma advice arentol. Tough to move from a weather sealed lens to non-weather sealed though.

I didnt mean to use the prime as a proxy in terms of results, but to see whether 2.8 gives you the exposure latitude you need. 2.8 at 50, is the same as 2.8 at 200.

Thanks Robert. I'd love the MKII....but can't justify spending that much (almost double the price of a second hand 2.8 MKI.....more than double the value of my f4IS).

From what I've read so far, most seem to think that if I can't get the MKII, then stick with the f4IS.

My next questions is, what would the recommendation be for indoor action? I've heard that the 85 1.8 is a good option....my only concern is the FL perhaps being too short.

DL Photo wrote in post #12076766
Thanks Robert. I'd love the MKII....but can't justify spending that much (almost double the price of a second hand 2.8 MKI.....more than double the value of my f4IS).

From what I've read so far, most seem to think that if I can't get the MKII, then stick with the f4IS.

My next questions is, what would the recommendation be for indoor action? I've heard that the 85 1.8 is a good option....my only concern is the FL perhaps being too short.

The 100f2, or 135L f2 are also good options.

Two suggestions:

1, Have a look at the EXIF data from the shots you have taken recently are they mostly at 70mm or 200mm or 100mm or are they all over the place. This will give you an indication if a prime will be godd enough.

2, There are 3 factors affecting exposure for a given light source - aperture, shutter speed and ISO. You probably have a fixed shutted speed for stopping action and you are trying to get better shots by having a wider aperture but have you thought about upping the ISO and then doing some noise reduction? Or even under-exposing your shots and fixing in PP? Or even both?

My mkI is tack sharp at 2.8. There are a lot of sharper copies out there too. I would get the mkI over the f4 version any day if the mkII is out of your financial reach. good luck

Well, it's just one stop difference... Will leaving everything else the same, shooting at f2.8 (with the resulting shallower DOF and perhaps not quite as sharp wide open as the f4 lens or stopping down a little bit would give you), and doubling your shutter speed be enough? I think the suggestion to test with your 50mm set to f2.8 was simply to see if that gave you enough additional speed to be worthwhile.

As a rule, the 70-200/2.8 IS "Mark I" is quite good wide open. It's close, but not quite sharp as the f4 version... not surprising really.

But my point is that although it's good wide open the f2.8 lens, like most, will be even better stopped down a little... If you crop a lot, for example, that might be a consideration. If necessary, stopping down would negate the stop you had gained, of course. (Side note: 7D images need considerable sharpening. If shooting JPEGs, you might be doing that in-camera... If shooting RAW, I find I need to use nearly double the sharpening I did with 50D. The 7D seems to have a stronger anti-alias filter. I haven't used them but would guess that the other 18MP cameras using very nearly identical sensors might need similar additional sharpening.)

Also, depth of field becomes a consideration when using a larger aperture. I've got several f2.8 or faster lenses, but don't necessarily use them wide open all the time, if DOF will be too shallow.

If you can live with a slightly less sharp image (emphasis on "slightly), and somewhat shallower DOF, and the gain of one stop is enough to get the shots... then it makes sense to look at swapping to the faster lens. If any of these considerations might be a problem, you might have to take another approach (such as bump up your ISO, buy Noise Ninja or similar, shoot RAW, and do more post processing on your images).

What are you doing with your images and what ISO are you using? I shoot 7D at 3200 fairly regularly, processing RAW files through Lightroom 3 (which has much improved noise handling compared to LR 2). Images are fine for up to 16x24 prints with little concern about noise. If you are printing considerably smaller or for the web, then you might have even less concern about noise and might be able to use higher ISO. I find the main thing with high ISO shooting is to avoid under-exposure at all costs. Even if exposed correctly, if there is a lot of deep shadow area in an image it will show noise in those areas.

Siggy is not weather sealed either don't forget. thats if it matters

No doubt that the MKII is an improvement and a superior lens but get a grip here. The 70-200 IS MKI has been a standard equipment lens for photojournalists and wedding pro's for years now. Many people feed thier kids with the quality it renders. Whan an improvement comes along it doesn't mean the last generation deteriorates or is less capable of performing well. There are some good deals on MKI around, grab one and you'll se it's a great lens "still". I love mine. If I could afford it I would have a MKII but I still love and use mine all the time.

^ what he said.