Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

For next year's wedding season I'm looking at purchasing a new lens to use on my Canon C100 during the ceremony instead of my current Canon 24-105 F/4. A friend of mine has the Canon 70-200mm F/2.8 non IS and he used it on our Canon 70D for the last couple weddings that we shot this year. I was really impressed with everything about the lens, but I did notice that for one of the ceremonies where he had to zoom in quite a bit, the minister was in focus but the groom was slightly out of focus. This was inside of a church so he had it wide open at 2.8 to get more light, but I think that shooting wide open was at least part of the reason for this (he was on the left side of the sanctuary and his shot was of the minister, the groom, and the back of the bride.)

I want to find out if others have had this same thing happen when shooting wide open with a very shallow depth of field with the F/2.8 lens? The reason I'm asking is that if this is fairly common when shooting wide open then I would probably stop the lens down to around F/4 and just bump up the ISO in my C100 as necessary. And if I end up doing this then I may as well save quite a bit of money and just buy the 70-200 F/4 version.

Next year we will likely be shooting with two C100s instead of using the 70D, so we could both potentially shoot at F/4 and increase the ISO in dimly lit churches without an unacceptable amount of noise.

So please let me know if anyone else has had this same thing happen when shooting with the 2.8 version wide open or if you have used the lens quite a bit and have figure out how to avoid this from happening.

Thanks,

Mike Silverman

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

If you want a larger dof you have to close down the iris and increase the iso to compensate. Have you not shot with fast lenses before? You can't avoid shallow dof if you open up the iris on larger sensor camera's and it only gets worse on the longer end of a telelens.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Well, just using a Mk3 here. What I'm finding is that f/4 is not practical for receptions, and that there are many times where I'm at f/2.8, 6400 ISO and 30 shutter speed and still starving for light.

Your C100 has cleaner high ISO than mine, but I'm sceptical that, even in the really dark environments, you'd want to push beyond 6400 (though I think the a7s could get away with it).

What's your experience been so far? Have you been happy at f/4 with other lenses at receptions?

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

For anytime you NEED to have any depth of field, I'd target f/5.6 or higher. I have gone down to f/4 in a pinch, but then have to pick who will be in focus.

f/2.8 is great during vows, with a clean shot of either the bride or groom's face. Or for your tight shot during the first dance. Really gives that feeling of them being the only people in the world.

Most of the time, though, at the reception its too dark and I need even faster lenses (70d and 5d Mark ii here), like the 85mm f/1.8

For the 70D, why not take full advantage of the focusing ability? The STM lenses like the 40mm f/2.8 or the 18-135mm is a nice 'on the move' lens. Otherwise, for ceremonies, our 70Ds use the 55-250mm f/5.6 STM for it's reach and smooth focusing/tracking, one for each the bride and groom.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I have shot with fast lenses before during the reception, but typically during the ceremony I have just used my 24-105 f/4. I will zoom in all the way to 105mm, stay wide open at f/4, and raise the ISO up and I usually get good results. However, I've found that 105mm is not quite as far as I would like to zoom and the 70-200 would give me more than enough reach.

I guess to make my question more concise, has anyone else shot with the 70-200mm f/2.8 wide open and had an issue where they cannot get both the minister and the groom/bride in focus at the same time when zoomed in to like 140-150mm? It's possible that my friend just missed the shot as he was pulling focus manually, but if it's common for the lens to do this at f/2.8 then I'd rather get the f/4 version and just raise up the ISO.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I just wrote my response before reading this reply. I think this makes a lot of sense that when isolating a single person, f/2.8 works well, but when it's necessary to get multiple people in focus it's better to stop it down. Next year we're planning to swap out the 70D with a C100 mk II (if funds allow us to). We didn't experiment much with the face tracking on the 70D but I think the C100 mk II has that with STM lenses as well. However, the reason why I like the 70-200mm is that the bokeh is amazing for a zoom and it also has the exact reach that I need during the ceremony. I'm just not a fan of having to add a lens support system but I'll get used to it :)

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

The facial tracking is the best! Especially for the processional and recessional. I usually have an STM lens (smooth on the focus) at around 28 or 40mm and, from up front, track everyone as they come in, then, once the bride gets up front, I retreat to my main camera position. It's great.

And if the reception isn't too dark, the 24mm or 40mm f/2.8 STM will do very nicely during dancing. I'm a big fan of camera movement, then, and while I'm decent at pulling focus manually, it's just so easy with the 70D.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

You first said that the minister was in focus but the groom was slightly out of focus so my question would be, who did he want to have in focus? If he wanted to have the groom in focus then yes, he missed the shot.

Shooting wide open with a f2.8 lens at longer focal lengths, like 140-150mm on a aps-c or larger sensor and depending on your distance to the persons you are shooting it's impossible to have them both in focus if they are in not the same distance from your camera, there is nothing you can do about that. Even at f4 you cannot have them both in focus if one is one meter further from your camera then the other, unless the distance between yourself and them is very large.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

My main product is stills and I use the 70-200 f2.8 IS a lot during ceremonies.

However I only go down to f2.8 if I absolutely have to because the depth of field is so narrow - even at the short end - that focusing is critical. Missed focus or focus on the wrong thing is much ,more noticeable in stills than in video but I still would avoid risking it for video. No way will you get two people in focus unless they are in exactly the same plane; even then you'll not get the whole head of one person in sharp focus towards the long end.

By all means use it at f2.8 for specific shots you want but don't rely on it for long clips or for shots that really matter unless the light is so low that you have to do that.

The weight and bulk are also significant.

But it is an "insurance policy". If you find yourself in venues where the light is otherwise unusable low it might be f2.8 or nothing.

So I think it would be a false economy to exclude f2.8 or image stabilisation.

You could pick up the mark one version much cheaper than a new mark two and the difference would be unnoticeable except by pixel peepers.

You could probably rent either cheaply in your area to try them out.

Pete

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

This is all really good information. With the 24-105 I've always been able to frame a shot from the side getting the bride and minister in focus while the back of the groom is slightly out of focus when at 105mm at F/4. However, I'm sure that would not be as easy when I'm zoomed into 140mm. From what I've read in this thread, the 70-200mm F/4 non IS will probably meet my needs since I will be on a tripod with very little camera movement (mostly just reframing and I can just cut to another shot then), and with the C100 I'm comfortable taking the ISO to 6400 in the case of a very dark church.

In order to be on the safe side, whenever I'm zoomed in past like 120mm I'll try to frame the shot so that only one person needs to be in focus so that I don't have the same issue my friend had. When I need to get all three in the shot then I can zoom out a bit so that there's a slightly deeper depth of field and I can get both the bride and minister in focus at once.

I like the idea that Robert had of using an STM lens for the processional. Right now I'm using my 24-105 which has worked will with the C100 continuous AF, but I do like the way the STM lenses work with the continuous AF and with the C100 mk II I can use the face recognition.

My friend was using a 70-200 f/2.8 mk I and really likes it. However, I'm always more comfortable buying gear new and I think he said the mk I is only available used. So I'll check out the prices of renting as we have one last wedding in about a month that I could rent it for. But I'd really like to save the money if I can with the F/4 if it's possible.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Get the f/4 and crank up your ISO when you need to. 2.8 is obnoxious on telephoto most of the time. The f/4 lens is lighter, cheaper and easier to handle. If you really need to, apply neat video to the DARK stuff and it cleans up like magic. The 2.8 canon is a fantastic lens, but there's a significant price difference that I don't think is worth it 98% of the time. If you foresee needing 2.8, rent or borrow for the day.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I'm in a similar position where I'd love to buy a 70-200 (have hired the 2.8 IS for my first two wedding shoots) and I can see that upping ISO could compensate for the difference in f stop. Issue is, in most reception settings my 6D will be pushed in terms of ISO at 2.8, so worry that f4 would simply be too dark.

The Canon 70-200 f4 IS is still more expensive than the Tamron 70-200 2.8 VC, so I'm wondering if anyone has a strong preference for either of these lenses?

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I use the 70-200 f4 IS on both the C100 and A7S, and anywhere near the far end (150mm onwards) provides a shallow depth of field when shooting at f4. Most of the times I end up stopping down to f5.6 however most often venues tend to be quite dark over here as well so shooting wide open is the only option. Obviously you'd need to choose where you'd like to focus. It's impossible to get both the foreground and background in focus like you were suggesting.

While I've never owned the f2.8 version, I've tried it out and I consider it to be way too bulky and heavy. For me, with the cameras I'm using, the difference between f2.8 and f4 is minimal so I'd rather get something which works better for me in terms of ergonomics. The f4 IS is perfect in terms of weight, so much so that I even do some run&gunning with it at 200mm handheld and manage to get smooth footage thanks to its incredible IS performance.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Malcom, do you find that the IS is helpful when using the lens on a tripod? I've heard some people say that it's best not to use IS while on sticks while other people say that the IS helps reduce vibrations and any "unsmooth" movements while zoomed in really far. I don't plan on using this lens handheld or on a monopod, so I would only use it on a tripod. The reason I ask is that the non IS version is much less expensive. Right now after mail in rebate, B&H is selling it for $609.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I always leave IS on even when the camera is on sticks. At such a focal length (especially on a crop-sensor camera) any sort of camera movement would translate to shake. As wedding videographers, we never know exactly how our environment is going to be - for example being situated on a wooden floor would result in quite a bit of shake every time someone walks by.

Maybe someone who's using the non-IS version can chime in :)

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I tend to leave IS on when I'm on sticks, and haven't had any problems that I've noticed... except for the sound of the IS, in cases where I've had to use in-camera sound.

My friend uses a 24-105 on a steadicam occasionally, and does sometimes turn the IS off, because he finds it can fight his framing.

Definitely makes a difference to monopod usage... and you might say now that you're not intending to use it on a monopod, but who knows in future?

I think whether there's a difference to tripods partly depends on the quality and type of your tripod and how prone it is to small shakes. For instance, if it's light, has a centre column, or is made of aluminium, then it'd be more prone to vibrations than a heavy tripod made of carbon fibre with a ball head.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

That depends how effective the IS is, I have a sony cx730 which has a very good IS (the lens itselfs also moves around to filter out any vibration) and I always have to deactivate the IS when I shoot on a tripod, if I zoom in and make a panning motion and when I stop the IS of the camera tries to compensate for that sudden stop and then you see your image bouncing around making it useless. Most other camera's don't have such effective IS but especially at the long end of the lens that stabilisation might give you unwanted movement on a tripod, so in some cases you are better off disabling the IS.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I have both the Canon 70-200mm F4 IS & F2.8 IS - 80% of the time I use the F4 leaving the F2.8 in my bag. F4 is such a brilliant, light weight, sharp lens the only reason I have the F2.8 is for when I need to use an extender which drops it down to F4. I always have a portable LED with me for fill light I am yet to encounter a ceremony/reception too dark for the C100 to handle.

My advice is buy the F4 IS. Image stabiliser is a must, micro vibrations are all over the place if you have no IS. I'm even thinking about selling my F2.8 to get another F4 or the newly announced 100-400. The F2.8 is heavy plus I don't film F2.8 during the ceremony or speeches anymore. The F4 has definitely become my little darling.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Alex, I've definitely been at receptions where I've felt vibrations in the floor from dancing. At ceremonies everything is usually exceptionally still. Are the micro vibrations coming from people moving around, from having one hand on the tripod handle, or is it something else?

The reason I'm asking is that there's a $500 difference between the lenses from B&H and I might end up buying two for the next wedding season. If I can save the $1000 and not regret it then I will certainly opt for the non-IS. What I may do is see if I can rent my friend's 2.8 non-IS for a wedding next month and see how the shots look without IS. However, I'm pretty confident that I will go with the F/4 version as it just seems like a better fit for me.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Michael the vibrations come from touching the camera mostly. If you want to make any adjustment, check focus, the slightest touch will cause the image to vibrate. If you buy a non IS you'll end up selling it for a IS eventually. I only switch off IS for a time-lapse but I won't touch the camera then. As mentioned, IS is brilliant for monopod shots or sliders. Think long term, the IS might seem like extra money right now but you'll end up buying two lenses (the IS to replace non-IS) if you don't go for IS from the start. If budget is tight try finding them 2nd hand? I'd recommend having two 70-200 in your kit brilliant for weddings.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Michael,

we get micro-vibrations from 1) touching the camera, 2) walking near a camera with certain floors, and 3) using the auto-focus and non-STM lenses.

For instance, I have two different wedding trailers I posted recently where you can clearly see the lens glass shake. I was using regular USM lenses instead of STM on our 70D. The shake is from the camera trying to nail the focus.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I think at this point I'm confident that I can live without the extra stop of light from the F/2.8 version and go with one of the F/4 versions. I think that in order to decide between the IS and non-IS I will rent the IS version to see the difference in person. I'm usually not a fan of renting gear but in this case it's a pretty big purchase (potentially two big purchases) and it should be very easy to do a test to see if the micro vibrations are an issue for me. I am one of those people that tends to always have their hands on the camera to make minor adjustments, so after a test shoot I should be able to make a firm decision.

Thanks for all your help everyone!!!

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

If the ceremony is outside the f/4 would be perfect, but for inside I would definitely stick with a 2.8. I've trued the f4 and it was basically worthless inside. :(

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Concerning the IS on a tripod. The manual for the 70-200 f4 IS simply advises to turn off the IS while on a tripod to save battery life. There is no mention of other problems if left on. Some of Canons recent lens recognize when it's on a tripod and turns off the IS, or something like that.

I use my 70-200 f4 IS on a tripod all the time and have never turned it off and have never had a problem with it.

Many reviews I've seen say the the 70-200 f4 is actually sharper than the f2.8.

I also bought the 70-200 f4 non IS...... and literally within a week sold it and bought the IS version.

I would never buy a zoom without IS.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Filmed an awesome wedding yesterday where the ceremony was held on a racetrack, and the bride and groom went drifting instead of doing a photoshoot. Since we couldn't get close to the action, part of our setup involved a 100-400 with a x2 extender. I was grateful for the IS when I had it on a monopod, but my second shooter preferred to turn it off when on a tripod -- said it was more responsive.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I personally think more options are better. You can always turn off IS or stop down if you want, but you can't turn it on or open it up to 2.8 if you don't have it. Why limit yourself?
The weight is not a factor if you are mostly on a tripod, anyway.
I bit the bullet on the 2.8 IS and think it is a great investment, and have long forgotten the extra money I spent...

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I just purchased the Canon 70-200mm F/4 for my C100 and I've shot a very small amount of indoor test footage in a room with plenty of light. This first test was to see how much of a difference the IS makes with the camera on my tripod using a rod system with a lens support. So far I've noticed that when I'm zoomed in quite pretty far, if I touch the camera with the IS off I do notice the microvibrations (they're actually very noticeable and could really affect the shot). When the IS is on, these vibrations seem to be far less noticeable or even non-existent. So I'm very pleased with the result of using the IS and at this point I am definitely glad that I spent the extra money to go with the IS version.

My next test will be going to one of the darker churches in this area (which is also very popular) and shoot some test footage at F/4 to see just how high I have to raise the ISO to expose the image properly. I'm crossing my fingers that the footage will look good because I really want this lens to work and would prefer not having to return it to buy the 2.8 IS version due to the increased cost. I'm planning to buy a matching lens for my b camera, so if the F/4 IS version works well then I will be quite pleased. I'll post an update once I've done more testing but right now I'm pretty excited as I like everything about the lens so far.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Really looking forward to your thoughts on the church footage at f/4 Michael! I'm in a similar position so would be great to know just how well it goes. Obviously your C100 will be superior for low light compared to my 6D, but would still be a great insight to have!

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

I just wanted to give an update that I just shot a wedding with my new Canon 70-200mm F/4 on my Canon C100 and the footage looks very good. I also did a low light test in one of the churches around here that is very popular and quite dim. I found that when shooting wide open at F/4 I was able to raise the ISO up to 5000 on the C100 and then run the footage through Denoiser II while still maintaining a nice looking image. While the F/2.8 version has an extra stop of light, I think I can get away with the F/4 version at ISO of 4000-5000 and still produce great footage. I also like how when shooting at F/4 it's a little easier to get multiple subjects in focus when zoomed in quite a bit. So at this point I'm quite pleased with the F/4 version and plan to cut out my UPC code from the box and send off the rebate, which means that I'm keeping it :)

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Try the Tamron 70 - 200 mm 2.8 A great lens. It comes with and without stabilization. Without it cost is $760. Very sharp great colors.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

How about the 600d with a 24-105 f4 for an indoor wedding. This will be the roving camera.

Okay or not?

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Fine, I guess, though the 600D is worse in every measurable except maybe the swivel screen being convenient compared to a 5d Mark ii.

The 24mm will still be 40mm equivalent on the crop factor, which is not wide, but still pretty convenient. You'd need Magic Lantern to give you access to some features, like Kelvin white balance and audio meters.

For not a lot more money, the 70D gives you focus tracking, which you'd want STM lenses to use with. Makes run and gun much easier, and gives you better ISO performance and 30 minute recording (it breaks the files into 4GB pieces for you). Canon's STM lenses are cheap, but the primes (28mm and 40mm) are of fair quality considering they're $150 each.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Depending on how dark the interior is, an F/4 lens my not be fast enough with the 600D. I own the Canon 24-105 F/4 and while it says it's a constant aperture, when you zoom in the image gets a bit darker. The two lenses that Robert mentioned are a full stop faster so they'll let in at least twice as much light than the Canon 24-105 F/4. This would be very helpful when the interior is fairly dim.

Another option is that Canon will be announcing a fairly inexpensive 4K camera call the XC-10 in a few weeks. This camera will have approximately a 1" sensor which will allow you to get a shallow depth of field when zoomed in (just like Sony's X70). If the camera ends up being pretty good in low light then this could be a nice option as it will give you a very sharp image with the internal 4K, the ability to obtain a shallow depth of field, and also a power zoom which can be helpful at times.

If you're looking at getting an F/4 lens then it may be helpful to get a camera that's quite good in low light. The Canon 6D would be a great option because it's fairly inexpensive right now and is great in low light. So if you walk into a church that is very dim you can bump up the ISO to 3200 (or maybe higher) and the image will look good. If you do see some grain in the image after raising the ISO, you can purchase Neat Video or Red Giant's Denoiser II which will clean up the footage very easily.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Hi Paul, this is just my opinion, but I wouldn't walk into a reception with f/4 only. As long as you've got at least a 50 prime to go with that 24-105, you should be alright. I think I wrote this earlier, but there's plenty of situations where I've been at f/2.8, 6400 ISO, 30 shutter on my Mk3s and still been starving for light. 2.8 has almost always been manageable for me -- just -- but nothing like the image you'd get from faster primes. But whether f/4 or f/2.8 are enough for you does depend on how dark the receptions get around your area, and what sort of noise you're willing to put up with.

On the other hand, videographers have been managing for decades with cameras that weren't great at night time. So, f/4 is okay providing you're willing to blast people with light.

Three more quick thoughts: (1) for dancing, I think you should try to stay at 50 shutter rather than squeeze more light out by dropping to 30 -- the motion blur may hurt your eyes; (2) definitely avoid high ISO whenever you can. It's not just the noise; it's also things like colour. Much better to give your camera enough light by opening the aperture than to starve it of light and then ask it to make the best of what it's got; (3) if you really want f/4, there's always the a7s option...

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Paul, I hadn't considered how the f/4 is really closer to f/5.6 on a crop factor. Then you've got the issue with the ISO on the 600D not being able to push as far as a lot of other cameras. Its been a while for me, but I think we never went above ISO 1600 on our T3i, if we could help it.

I have a decent number of ceremonies where that wouldn't cut it, never mind receptions.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Thank you all for the time spent replying to my question. I seem to have opened a can of worms with this and my apologies to the OP for hijacking the thread with my query. Forgive me for a few follow up remarks:

There is a significant price jump here. To move from the 600D to the 70D would in fact be twice the cost (in the UK - 300 odd pounds to 600 odd) and to get to the 5d iii would be an even larger leap. It's maybe something I can aspire to, but at the moment I am going to need to use the 600D.


I've googled this up by can't find any mention of it. I'm assuming it's going to be a 4 or 5 thousand dollar camera though, in which case that's going to be a hire only item for me for sometime.


I do have the nifty fifty, I also have a 2.8 28-70 sigma, but it tends to be soft at 2.8. I will have to lurk around my local church at random times of the day to see what sort of results these give me. But yes, unless it is a bright church, the F4 sounds as though it won't be up to the job, and as it only gives me a little more reach than the sigma it might not be a sound investment at this stage.


I haven't seen this effect where the crop factor also effected aperture as well as the field of view. I've also experimented with ISO and filming at 1600 seems to be about the max my camera can cope with.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Paul, is the price difference still true for a gently used 70D? That is what I was suggesting. Better to figure out a way to get the more useful camera now rather than buy the 600D and then replace that after a year or two. That was a mistake we made.

The money will be saved on your lenses, then. If you want facial tracking auto focus on the 70D, you use the STM lenses. All 4 of the most useful together will still cost less than the 24-105 f/4. I would suggest the pancake lenses, 28mm and 40mm f/2.8; and the 28-135mm STM, and the 55-250mm STM for long reach. We also use a Sigma macro 17-70mm f/2.8-4 and the 50mm f/1.8 or 35mm f/2 for when the f/2.8 won't cut it.

Remember that the crop factor effects everything, so that aperture rating set for a full frame is not the same for a crop factor. Photographer Tony Northrup has a decent explanation to show how the differences pop up. You can find the video pretty easily.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Sorry, not making myself clear here, I already own and use the 600d. To be honest I've not found the manual focusing yo be that much of a problem.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Paul, if you want to get a variety of shots during the ceremony with the 600D then you'll probably want a fast zoom lens that will be sharp wide open. Unfortunately, I've found (like you've seen with the Sigma 28-70 F/2.8) that many of the cheaper F/2.8 zooms are fairly soft wide open and only get sharp when you stop them to around F/4. I bought the Tamron 28-75 F/2.8 for my 70D last year but it ended up being extremely soft on my 70D unless it was stopped down to at least F/4. The reason I bought the lens was to for the extra stop of light but it didn't not provide what I was hoping for.

From my experience, if you want a fast zoom lens that lets you shoot wide open and retain sharpness then it's best to go with one of the pricier zoom lenses. I know that the Canon 70-200mm F/2.8 and the Canon 24-70mm F/2.8 are very sharp when wide open. I have heard that then Canon 17-55mm F/2.8 is pretty sharp wide open, but you may want to do some research on it or rent it because it's probably not as sharp as either of the first two I mentioned. There are likely other ones out there but those are the three that I'm most familiar with because I've looked into buying them.

Since this is a roving camera for you, the other option is to use your 50mm prime and then purchase the Canon 85mm F/1.8 and perhaps the Canon 28mm F/1.8 and then swap lenses when you want to get a tighter or wider shot. I've found that even when just stopped down to F/2.0 these lenses are quite sharp and also a full stop faster than almost any zoom lens. It's not ideal swapping lenses, but you get used to it after a while and you will also be able to get some very nice bokeh when shooting at F/2.0.

Regarding the Canon XC-10, here's a link to the specs on the camera:

XC10 « Canon Rumors

The rumored price is around $2K US street price which I think is very reasonable. However, you'll want to wait until test footage comes out to see how well it does in low light. My guess is that with a 1" sensor it will be fine for most ceremonies, but I doubt it will be something you can use at most receptions.

If you want the solution to allow you to shoot at receptions and dimly lit churches then I would go with a couple of Canon prime lenses because you'll be able to let in the most light to your camera and they won't break the bank as long as you don't go for the L series primes.

Re: Canon 70-200mm F/4 vs. F/2.8 for Ceremony
 

Isn't it a shame that Tamron and Sigma 2.8 lenses don't measure up to Canon L glass when wide open?

I guess I will need to hire again. I have hired the 24-70 2.8L from Lens for hire (great company to hire from in the UK by the way) and although I loved the image quality, the lens itself was built like a tank and had a Lens Hood that looked as though it had escaped from a wind tunnel (or clown circus act). But a great lens.

I wonder though if I am hiring if I would not be better off with the 70-200 2.8L and use that as the CU camera, with another giving me my wide shot. I would favour hiring an L zoom rather than buying several primes, even though I love my 50 1.8 and would love the 85 1.8, I am not sure I want to be changing them during a live event.

See OP, I am almost back on topic to this thread :)

And now to veer off again :)

Are there rumours of a 80D? Just in case the 70D might start to price crash. Also, what about rumours of a 800D that might have some of the focus tracking of the 70D?