Some screen caps with T3i with the Canon 17-55mm lens with and without the 3X crop zoom.

at 17mm
http://lacoloronline.com/blog/images/t3i/zoom11.jpg

at 55mm
http://lacoloronline.com/blog/images/t3i/zoom21.jpg

at 17mm 3x Zoom
http://lacoloronline.com/blog/images/t3i/zoom31.jpg

at 55mm 3x Zoom
http://lacoloronline.com/blog/images/t3i/zoom41.jpg

With this 3x crop zoom feature, it turns the 17-55mm lens into 17-165mm lens (neglecting the 1.6 APS-C crop factor). That's pretty sweet.

I just bought a 600D/T3i on Saturday but went cheap with the Tamron 17-50mm F/2.8 lens at less than half the price of the equivalent Canon lens. The 3X crop zoom is amazing as it effectively gives me an 80-200mm F/2.8 lens for free. I have been using 5DIIs for the last couple of years & this is the first APS-C Canon DSLR that I have owned & have been really pleased with it. I got the 600D as a cheap B-cam not expecting too much but it feels pretty similar to the 5DII in my hands & the fact that it is more oriented to video than the 5DII is very nice. The video I have shot so far looks indistinguishable from 5DII footage although I haven't shot in low light yet where I expect (hope?) that the strengths of the 5DII will be more apparent. I like the 1.6X crop factor making my long lenses even longer e.g. 135mm F/2L becomes 200m F/2L which would cost getting on for $6000 for that lens on my 5DII. With the 3X crop mode that lens becomes a 600mm F/2L! For really dark venues I can now use my 50mm F1.2L as a 240mm F1.2. Wow!

That's one of the reason I upgraded T2i to T3i. =)

Just curious how you get your number calculated. How you get 17-50mm to 80-200mm with the 3x zoom?

That's one of the reason I upgraded T2i to T3i. =)

Just curious how you get your number calculated. How you get 17-50mm to 80-200mm with the 3x zoom?Rounding error. I meant to write 80-240mm which makes my new free lens even better value:-).

17 x 3 = 51
50 x 3 = 150

Wouldn't the 3x zoom multiply the zoom range from 17-50 to 51-150mm ?

17 x 3 = 51
50 x 3 = 150

Wouldn't the 3x zoom multiply the zoom range from 17-50 to 51-150mm ?Plus the APS-C 1.6X crop factor which gives the following 35mm equivalent:

17x3x1.6=81.6
50x3x1.6=240
the normal non-zoom range for the lens is of course
17x1.6=27.2
50x1.6=80

I am used to the full frame 5DII so think in those terms. In round figures 28-80mm & 80-240mm all at a constant F/2.8 will cover 95% of what I need this camera for.

I am now beginning to regret being cheap & going with the Tamron 17-50mm F/2.8 over the Canon 17-55mm F/2.8 as from what I read the lens quality of the Canon is better (as expected) but the noisy OIS of the Tamron is going to be a problem. This was my first APS-C & EF-S purchase so I didn't want to spend too much in case it didn't work out but as it turns out it has exceeded my expectations & I think that this may end up being the camera that I use to shoot video the most unless there are those special situations like low light where the 5DII will be better. I think that I will probably take the Tamron back for a refund & get the Canon instead which will give me a little longer reach & (in round figures for 35mm equivalent) 28-88mm & 82-264mm.

Crop factor does not zoom. The focal length doesn't change, it just takes 1.6x in the center of the frame. So your lens doesn't become a longer lens, it just has the "crop" tighter. it's just like zooming in post, you don't actually make your shot closer, you just pull it in and cut off the edges.
Bill

Crop factor does not zoom. The focal length doesn't change, it just takes 1.6x in the center of the frame. So your lens doesn't become a longer lens, it just has the "crop" tighter. it's just like zooming in post, you don't actually make your shot closer, you just pull it in and cut off the edges.
BillThe lenses don't change focal length but the field of view does change depending on the size of the sensor & ignoring some differences with perspective the narrower field of view of the APS-C compared to a full frame sensor looks like you zoomed in. It's not the same as zooming in post as when you do that you are cropping down from 1920x1080 & ending up with less resolution because you are throwing away part of the image. Using the 1.6X multiplier for APS-C sensors is just a handy rule of thumb when comparing the field of view versus the same lens on a full frame camera. A 50mm lens on an APS-C camera has the same FoV as an 80mm lens on a full frame.

Crop factor does not zoom. The focal length doesn't change, it just takes 1.6x in the center of the frame. So your lens doesn't become a longer lens, it just has the "crop" tighter. it's just like zooming in post, you don't actually make your shot closer, you just pull it in and cut off the edges.
Bill

Despite all the technical stuff, the way it works does make it feels like I have a longer lens. I think that's the most important that it gives me the extra flexibility in framing the shot, without moving or changing lens.

It is definitely NOT the same as zooming in post. Zooming in post is stretching pixels which cause loss in quality. The 3X crop zoom has no quality loss.

Plus the APS-C 1.6X crop factor which gives the following 35mm equivalent:

17x3x1.6=81.6
50x3x1.6=240
the normal non-zoom range for the lens is of course
17x1.6=27.2
50x1.6=80

I am used to the full frame 5DII so think in those terms. In round figures 28-80mm & 80-240mm all at a constant F/2.8 will cover 95% of what I need this camera for.

I am now beginning to regret being cheap & going with the Tamron 17-50mm F/2.8 over the Canon 17-55mm F/2.8 as from what I read the lens quality of the Canon is better (as expected) but the noisy OIS of the Tamron is going to be a problem. This was my first APS-C & EF-S purchase so I didn't want to spend too much in case it didn't work out but as it turns out it has exceeded my expectations & I think that this may end up being the camera that I use to shoot video the most unless there are those special situations like low light where the 5DII will be better. I think that I will probably take the Tamron back for a refund & get the Canon instead which will give me a little longer reach & (in round figures for 35mm equivalent) 28-88mm & 82-264mm.

Thanks! Got it! I forgot about the 1.6 factor in it =)

I have Sigma 17-50mm F2.8 and Canon 17-55mm F2.8. The reason I bought the Sigma instead of Tamron was because Tamron has a different zoom ring and focus ring direction than the Canon. So I don't want to be all disoriented. =)

Another great feature of Canon over Sigma is, I can still manually adjust the focus ring while in AF mode. For the Sigma lens, when set to AF mode, the focus ring is very tight to be adjusted manually. I have to switch to manual focus before setting focus myself. So for the Canon, just set to AF mode and I can half-press shutter button to focus, or use the focus ring.

The Canon lens is noticeably faster in auto focus, and sharper. The sharpness can be tell just through the LCD screen.

I am definitely taking the Tamron back tomorrow & will pay the extra to get the Canon instead. The difficulty using manual focus when switched to AF & backward focus direction would drive me nuts when using the lens on a real paying gig. That combined with the noisy OIS, slow AF & lesser optical quality has made the decision for me.

Thanks Taky for posting these results. I am already sold on the t3i, I'm just waiting for a few more weddings to go ahead pay for it. That combined with the no overheating, is a done deal. I don't even know why they still make the t2i, for only $100 less. I will have two t2i's to go with the t3i for magic lantern. But once they get magic lantern all tested and ready to go for the t3i, I will sell them both and upgrade those as well. The overheating is a big deal for me, especially here in Texas. Its 100 degrees outside and they reach overheating withing 30 min outsides..No Good!!!

Hey Taky let me ask you this, would you get the 28-70mm f2.8 or the 17-50mm f2.8. I want to be able to zoom to at least 250mm but if i have the 17-50mm that would mean I would be at 5x zoom. I don't mind doing that occasionally but not all the time! What are your thoughts on that?

Together with the articulating LCD screen and manual audio control, t3i beats 60D IMO. =)

The reason I bought the 17-55mm F2.8 instead of the 28-70mm F2.8 is the OIS. It's necessary to have OIS when shooting video. People keep saying Canon will release a new version of 28-70mm F2.8 with OIS.. Until that is available, 17-55mm F2.8 would be a better option.

point was, beyond my flawed example is that the crop factor does not make the lens into anything, it just crops. This 3x feature on the T3i looks very interesting though because it does seem to zoom in... that means my 70-200 becomes a 210-600... yoikes! at 2.8 yoikes! with IS yoikes!
Bill

Sometimes I feel like we need to shift away from discussions around focal length and start thinking in FOV. It would remove all the arguments around the crop factor etc. In the mean time 35mm equivalent will have to do.

Also, just thought it was worth mentioning in the x becomes y debate that the DOF is deeper when comparing the 3x effect with a lens which is really 3x longer but has the same maximum aperture.. Probably not such a bad thing, but worth remembering. Zoom to 3x, on a 50mm f/2.8, and yes it's a 240mm 35mm equivalent (awesome), but still has the DOF of the 50mm f/2.8, not a real 240mm f/2.8

I very much agree the discussion what's the "real" focal length or not goes no where. FOV is what I care at this point and having the the extra zoom power to this standard zoom lens. On the same note, I wouldn't be too concern about the DOF as the 2.8 wide aperture already give me satisfactory result. I think for those including me who's happy with the 3x zoom wouldn't not mind not getting the DOF from a real 240mm F2.8 lens =)

Compared to the previous weddings that I have to carry the 17-55mm F2.8 and the 70-200mm F2.8L. Switching lens is always troublesome. I also worry people would be stealing my lens, or kicking it by accident if I have to leave me around. I am just happy to have 1 lens that can do wide shots as well as close up with just 3-button pressed, just like the cake cutting scene.

http://lacoloronline.com/blog/images/t3i/cake-full1.jpg

http://lacoloronline.com/blog/images/t3i/cake-zoom1.jpg

I very much agree the discussion what's the "real" focal length or not goes no where. FOV is what I care at this point and having the the extra zoom power to this standard zoom lens. On the same note, I wouldn't be too concern about the DOF as the 2.8 wide aperture already give me satisfactory result. I think for those including me who's happy with the 3x zoom wouldn't not mind not getting the DOF from a real 240mm F2.8 lens =)

http://lacoloronline.com/blog/images/t3i/cake-full1.jpg

http://lacoloronline.com/blog/images/t3i/cake-zoom1.jpg

Yes, I'm with you all the way. The DOF is not an issue for me. Actually there are benefits. Good reach in low light without the un-manageable DOF.

Just waiting for ML to mature before I trade up from the 550d

Just waiting for ML to mature before I trade up from the 550dWhat do you feel that you need Magic Lantern for that would stop you buying the 600D? It already has manual audio levels & I have been shooting with the 5DII for over 2 years & haven't seen anything useful in ML that would make me want to put up with the bugginess of it.

What do you feel that you need Magic Lantern for that would stop you buying the 600D? It already has manual audio levels & I have been shooting with the 5DII for over 2 years & haven't seen anything useful in ML that would make me want to put up with the bugginess of it.

The fact that ML is already under development on the 600d means I don't have to choose, I just have to wait.

I can only comment on the 550d version, but I don't have a problem with bugs.

Things on a 550d with ML that I like:

Trap focus
Magic zoom
Focus peaking
RGB Histogram
Zebras
Kelvin WB
Audio monitoring
Crop marks

These are things I feel I wouldn't be without, but there are a few other things that I like to play with.

The manual Alex produces is an impressive read if you're interested.

As for the 5DII the work being done by AJ is also impressive, so if you haven't had a look already....

What do you feel that you need Magic Lantern for that would stop you buying the 600D? It already has manual audio levels & I have been shooting with the 5DII for over 2 years & haven't seen anything useful in ML that would make me want to put up with the bugginess of it.

I too am eagerly awaiting ML for the 600D before I consider it. Without ML, I would not want to use my 550D on a professional shoot, particularly for a wedding where everything must be right the first time.

The audio with Magic Lantern is much better. You have a wider range of control as well as the ability to adjust and monitor it during recording - when it actually matters.

The histogram is unbelievably useful for me. I shoot a lot of surfing and becuase there is so much whitewater/glare the exposure meter is easily tricked and not to be trusted. The histogram, however, lets me know exactly where the highlights/mids/shadows are and gives me a better overall representation of my exposure levels.

I aslo use Kelvin WB to match cameras perfectly.

Magic zoom is also an awesome feature, letting me accurately adjust focus without having to stop recording to use the focus assist.

Other features I use regularly are the cropmarks, continuous recording, lens data (really helpful when setting up steadicam shots), and zebras.

I've never had any problems with bugs at all and have found it completely stable.

Continous recording would be the feature I love to have =)

It's not perfect continuous recording - there is a few seconds gap where it stops and restarts - but at least it means you can use it as an unmanned camera for weddings, rather than having to use a camcorder and try to match the footage later on. You can switch the LCD screen off too which saves battery power and prevents overheating.

I would just be happy even with the continuous recording if there's a few seconds lost. Hopefully it will be on ML for T3i.

I too would just be happy with just the almost continuous recording feature. I shall have to look at the 600D version of ML when it is mature. My only experience thus far has been with the AJS version for the 5DII & as far as I understand it this is a completely different piece of software sharing only the Magic Lantern name. My experience with that one is that it would hang every so often requiring hard reboot by removing the battery which is not something that I would want to happen in the middle of an event. I am still not convinced about the necessity of all the other bells & whistles as I don't find it that hard to get accurate focus or exposure on the 5DII without it but do have a couple of years experience. I don't know about the 550D/600D version but the peaking & zebras on the AJS version are not of the quality that I expect to find on a 'proper' video camera & I would rather do without them than have an ugly less than useful version even if it wasn't buggy.

I too would just be happy with just the almost continuous recording feature. I shall have to look at the 600D version of ML when it is mature. My only experience thus far has been with the AJS version for the 5DII & as far as I understand it this is a completely different piece of software sharing only the Magic Lantern name. My experience with that one is that it would hang every so often requiring hard reboot by removing the battery which is not something that I would want to happen in the middle of an event. I am still not convinced about the necessity of all the other bells & whistles as I don't find it that hard to get accurate focus or exposure on the 5DII without it but do have a couple of years experience. I don't know about the 550D/600D version but the peaking & zebras on the AJS version are not of the quality that I expect to find on a 'proper' video camera & I would rather do without them than have an ugly less than useful version even if it wasn't buggy.

It would probably change my view if I had the lock ups. The fact is, I've not once had to take the battery out.

Maybe if I had your experience, or maybe your eyesight, I wouldn't feel the benefits of the exposure and focus assistance tools, but they really do help me, even with a 3x loupe.

But the audio monitoring is really a must have for me.

The other point is that it's always growing and developing, and it seems more and more developers are being attracted to contribute. I love the fact that the possibilties of the camera can expand while you own it, rather than always needing a better camera. Not only that, but you can get involved and steer things a little yourself.

For example, I asked Alex if an RGB histogram would be possible when at the time there was only the luma one available. 3 days later, it was done and released, with the help of some of AJ's existing code.

As much as I hate to admit it, I have to agree with Nigel on this one. My t2i does lock up every so often, to where you have to take the battery out. But the bad part is, if it is recording when that happens, then you completely lose the clip.

I was shooting a high school graduation 3 weeks ago, and then bam, the screen goes black. I have to take off the quick release plate and remove the battery. what made matters worse was, it was about 4 minutes into recording a new clip when it happened. I guess it doesnt close out the clip when it hangs like that. But whatever the reason, I completely lose that 4 minutes of footage because it will not play back in the computer at all.

I love some of the features of magic lantern, but as I move to the t3i, I may not install Magic lantern on it when it comes. Which is a shame but that hanging up and loosing footage aint going to work for me!!!

You guys have to look at this way. The ML firmware is to assist you and it not for you to rely on it. You know from start that "use at your own risk" so when you do some major shoot and you need reliability you should have not use it but rather us the original firmware. I love how the ML run on 5D2 from the card and not permanent so it only a few second to change your mind about yeh or ney on ML for that shot. Like the gh1 hack it freaking crazy reverse engineer but everything come at a price it the users choice to know when to use it

If I cannot rely on ML 100% getting the shot then I would prefer never to rely on it for focus & exposure & just practice my own camera skills.

As much as I hate to admit it, I have to agree with Nigel on this one. My t2i does lock up every so often, to where you have to take the battery out. But the bad part is, if it is recording when that happens, then you completely lose the clip.

I was shooting a high school graduation 3 weeks ago, and then bam, the screen goes black. I have to take off the quick release plate and remove the battery. what made matters worse was, it was about 4 minutes into recording a new clip when it happened. I guess it doesnt close out the clip when it hangs like that. But whatever the reason, I completely lose that 4 minutes of footage because it will not play back in the computer at all.

I love some of the features of magic lantern, but as I move to the t3i, I may not install Magic lantern on it when it comes. Which is a shame but that hanging up and loosing footage aint going to work for me!!!

I agree with Nigel on this too. As I said, if I had the lock ups, I would ditch it. It's interesting that some get this while some don't. I guess the only variables here are the version you use and the card you use.


If I cannot rely on ML 100% getting the shot then I would prefer never to rely on it for focus & exposure & just practice my own camera skills.

I can totally see your point of view. I am a low budget amateur film maker, not an event videographer (too stressfull for me), so I may have a different perspective.

To return to discussion of the 3x Crop Zoom. I shot a wedding yesterday with the 600D & Canon 17-55 F/2.8 & found the feature really useful that gave me great close ups of the couple & celebrant from where I was at the back of the room. The articulated screen was great when the congregation all stood & blocked my view as I could lift the camera above their heads. The IS is really good on the lens too. I was also very pleased at how good the audio was. We were recording sound from wireless lav on an H4N & a shotgun on a Canon XF305 so weren't even thinking about recording on the 600D but the sound was good & rich from the internal microphones with little or no hiss or pumping even though I assume it was on auto levels.

I'm a bit late to this discussion, but can someone tell me what this 3x crop factor is all about? I have a 60D BTW.

You don't have that feature on 60D. Sorry =)

It's the camera using the inside 1920x1080 pixel from the entire 18MP sensor. In that case, it's a digital zoom by cropping but there is no loss in image quality.

...It's the camera using the inside 1920x1080 pixel from the entire 18MP sensor. In that case, it's a digital zoom by cropping but there is no loss in image quality.

That is probably not true.
I have yet to see people mention this--if 3x digital zoom just crops the center portion then it implies that you are getting one nineth of the amount of light going into your video. The IQ is bound to suffer. Sure, the resolution remains the same but you lose more than three stops of light, which means poorer light sensitivity and less dynamic range.
3x zoom feature is nice to have in good lighting conditions, but there is no free lunch here.

I have been using this features for the last 2 weddings. If it loses 3 stops of light, I'm sure I will notice. You can go back to the first post to see the pictures. They were shot at the same settings in the camera. The crop zoom picture doesn't look darker.

Or you can think of, in still photos situation. You took a picture with 18 megapixel. Then crop to the center 1920x1080 pixels. The picture you cropped out has the same brightness.

That is probably not true.
I have yet to see people mention this--if 3x digital zoom just crops the center portion then it implies that you are getting one nineth of the amount of light going into your video. The IQ is bound to suffer. Sure, the resolution remains the same but you lose more than three stops of light, which means poorer light sensitivity and less dynamic range.
3x zoom feature is nice to have in good lighting conditions, but there is no free lunch here.

I don't think this is right Lee. In zoomed mode, the camera is receiving the same number of lumens per pixel as in non zoomed mode, and the number of pixels contributing light to the image remains the same, or there abouts.

If the cropping doesn't affect light sensitivity there is no point in having a larger sensor beyond the DOF control. The fact that full sensor cams have much better low light performance is well documented. The same has to be true here, at least to some extent.

..Or you can think of, in still photos situation. You took a picture with 18 megapixel. Then crop to the center 1920x1080 pixels. The picture you cropped out has the same brightness.
That's exactly my point, Taky. The picture cropped out is much smaller now, so stretched out to the same size of the video frame, it will have less light per pixel.
Of course, we know that Canon throws away many pixels in video to begin with (under limited processing power). But some day--and I am sure that day will come when chip processing power is up to task---Canon will use all the pixels on the sensor to form video frames. Then the 3x cropping will indeed reduce the light by a factor of 9. My guess is that current Canon algorithm reduces the light by a factor of three, assuming that chip uses line skipping.

We all know camcorders with smaller sensors perform poorly in low light. It's a well known fact. However, the way this 3X crop doesn't mean it turns the camera into a smaller sensor. In standard mode, the entire 18MP sensor was used then scaled down to 1920x1080 (thus causing the moire pattern). In the crop zoom mode the same 18MP sensor was used too but only the center 1920x1080 is outputted.

Your thinking of the cropped picture is "stretched" to the same size of video frame. It is incorrect. The video frame is 1920x1080. There isn't any stretching at all. It is cropped to 1920x1080 (the video frame size). That's 1:1 and no stretching.

Again, you can go back to the first post to see the screen grabs. The crop zoomed pictures are not darker than the regular pics.

If the cropping doesn't affect light sensitivity there is no point in having a larger sensor beyond the DOF control. The fact that full sensor cams have much better low light performance is well documented. The same has to be true here, at least to some extent.


There is no light loss with the 3x crop. What it comes down to is each photosite on the sensor having the same sensitivity as the others. No matter which 2,000,000 pixels you use, it is still going to add up to the same amount of light being sampled.

The DSLR's have better lowlight sensitivity not a result of the larger sensor size, but because of the lower pixel density. The balance of sensor size vs resolution will determine the pixel density, and a lower pixel density allows larger individual photosites - this is where the better sensitivity comes from.

Saying a larger sensor has better light sensitivity is only true on an apples to apples comparison - ie if there is always the same amount of pixels and the pixel size stays in proportion to the sensor size.

I understand your points, Taky and John, that is T3i takes 1920x1080 pixels from the 18mp sensor and throws away rest of it no matter what. Only if that is true that 3x crop doesn't affect the light sensitivity. And it seems that this may indeed be the case with Canon DSLRs.
Now it is a very worrisome fact with T3i, and other current Canon DSLRs as well, because it implies that their video only utilizes one nineth of the available signal coming out the sensor. No wonder Panasonic GH2 with only half of the sensor size trounces T3i in terms of noise in its video, since it average all pixels to get the signal. And in GH2 you do see light loss with 2.6x crop.
I say worrisome because it means T3i is not worth buying new at this point as Canon can easily implement what Panasonic has done and improve IQ in T4i many folds in terms of S/N ratio (which means better low light, less noise and more dynamic range).

Lee, you worry too much. =)