L Lens on a small format camera-> T2i?

56_kruiser wrote in post #12145890
I was speaking with a friend, and he said he has spoke with someone at a local camera shop and asked about an L lens on his small format camera. He was told that on that type of body, an L lens is not particularly a good idea.

Comments?

I'm taking the salesman's advice and I'm now getting rid of my 135L

Considering crop cameras rely on center sharpness even more than full frame, I'm floored by some of these experiences.

First, one thing I will say regarding the camera shop: (I don't really care to defend them), but anyway, I did not get the full context of the conversation, so was unable to report it here. But this has triggered a very interesting thread (at least to me).

One thing I have done related to this topic: I have a 70-200 2.8 Ultrasonic L non-IS lens in my possession for a couple weeks.

Yesterday, I went out front and took some pictures with that lens, and my 55-250 F4-5.6 IS lens. I was wanting to compare pictures. So I set up to take the exact same photo, changing lenses to get it again, with both set at f.4, and 70mm, during the afternoon.

I then put the photos on my computer and tried to compare. Zoomed in to look at it extremely close; I compared the exif information. Studied color, and detail.

Frankly, about all I could find for difference was that the L lens, with its larger lens diameter, took the same picture quicker. Did it several times, and found in one example, mine took it in 1/500, the L did it in 1/1000; another time mine 1/1000, the L 1/1250. I"m new enough to this that I thought maybe mine may look a bit grainy in comparison, but that didn't seem to be the case.

I realize of course the quality material differences, but my questions and concerns, at this stage in my photography excursions, is quality of picture.

The one thing for sure I do interest in is getting 2.8 vs 4.0 lens.

At the moment I'm struggling between the 50mm 1.4 vs 1.8, and 1.2. Given the cost of a 1.2, and my very early stages in photography,I won't be getting the 1.2, but am leaning a bit to the 1.4. (Have read several threads here on that topic, and hard to say what's best) And, I have no idea if I would / will ever be good enough to make $ with this, so not sure I want to spend that kind of money.

BTW...I did find one video comparing the 3 lenses, and a site with some discussion and pics, and the 1.2 does definitely seem to provide the best pictures. But at quite a price difference.

That salesman is a moron!

Bokehlicious wrote in post #12145977
It might not be "a good idea" depending on specific L lenses because on a crop, the field of view will not be the same as on a full frame. ie. the 17-40 is a good wide angle zoom lens but it's not that great on a 1.6x cropper (27-64 equivalent FOV).

Bokehlicious wrote in post #12146211
17-40 isn't f2.8. Note that I said "specific L lenses". There's little reason so get a 17-40 for a 1.6x crop when there are a few better alternatives.

The focal length is the same, it's the equivalent FoV that's different.

Unless you are planning to upgrade to FF in the near future, want the extra length at the end. and want the better build, there's little reason to get a 24-70 for a crop. 17-55 or a siggy 17-50 would be a better suggestion.

I'm not saying that the salesman is a genius but there's a certain degree of reasoning behind that saying though it might be too general.

So you and the salesman in question think that you know better than me what focal lengths are best suited to what and how I shoot? You think you have the right to dictate what focal ranges are most useful to me?

I find the content of the quoted posts offensive.

56_kruiser wrote in post #12146959
First, one thing I will say regarding the camera shop: (I don't really care to defend them), but anyway, I did not get the full context of the conversation, so was unable to report it here. But this has triggered a very interesting thread (at least to me).

One thing I have done related to this topic: I have a 70-200 2.8 Ultrasonic L non-IS lens in my possession for a couple weeks.

Yesterday, I went out front and took some pictures with that lens, and my 55-250 F4-5.6 IS lens. I was wanting to compare pictures. So I set up to take the exact same photo, changing lenses to get it again, with both set at f.4, and 70mm, during the afternoon.

I then put the photos on my computer and tried to compare. Zoomed in to look at it extremely close; I compared the exif information. Studied color, and detail.

Frankly, about all I could find for difference was that the L lens, with its larger lens diameter, took the same picture quicker. Did it several times, and found in one example, mine took it in 1/500, the L did it in 1/1000; another time mine 1/1000, the L 1/1250. I"m new enough to this that I thought maybe mine may look a bit grainy in comparison, but that didn't seem to be the case.

I realize of course the quality material differences, but my questions and concerns, at this stage in my photography excursions, is quality of picture.

The one thing for sure I do interest in is getting 2.8 vs 4.0 lens.

At the moment I'm struggling between the 50mm 1.4 vs 1.8, and 1.2. Given the cost of a 1.2, and my very early stages in photography,I won't be getting the 1.2, but am leaning a bit to the 1.4. (Have read several threads here on that topic, and hard to say what's best) And, I have no idea if I would / will ever be good enough to make $ with this, so not sure I want to spend that kind of money.

BTW...I did find one video comparing the 3 lenses, and a site with some discussion and pics, and the 1.2 does definitely seem to provide the best pictures. But at quite a price difference.

If you're debating about 50mm's, the Sigma 50mm f/1.4 is much sharper than the Canon 50mm f/1.4 for a similar cost.

Did he try and sell you a special UV filter for digital cameras only? Stay away from that saleman!

Maybe he's trying to get fired, or is p*ssed off at his boss.

56_kruiser wrote in post #12146959
One thing I have done related to this topic: I have a 70-200 2.8 Ultrasonic L non-IS lens in my possession for a couple weeks.

Yesterday, I went out front and took some pictures with that lens, and my 55-250 F4-5.6 IS lens. I was wanting to compare pictures. So I set up to take the exact same photo, changing lenses to get it again, with both set at f.4, and 70mm, during the afternoon.

I then put the photos on my computer and tried to compare. Zoomed in to look at it extremely close; I compared the exif information. Studied color, and detail.

Frankly, about all I could find for difference was that the L lens, with its larger lens diameter, took the same picture quicker.

Often, you may not see any optical quality difference between images made with consumer-grade and "L" class lenses. The better lenses, though, will generally last longer under heavy use simply because they are better built for a lot of use. They also typically focus faster when using autofocus. I suspect that low-priced consumer-grade lenses may be more prone to flare and other image quality degradation (than the "L" series) when there are bright light sources impinging directly on the front lens element, but I have not tested this.

A huge difference (for me, at least) between lenses like the two you compared is the fact that front end of the 55-250 rotates (I believe when focusing) and that can be a problem if you are using a polarizing filter. Because a polarizing filter has to be rotated to the right position for the desired effect, it is a bad idea to have the lens' front end rotate because that mean you'll have to readjust the filter and doing that could affect focus, etc. The "L" lenses do not have rotating front elements.

The only lenses I have for my 20D are all "L" class lenses. They all perform just great.

SkipD wrote in post #12148102
Often, you may not see any optical quality difference between images made with consumer-grade and "L" class lenses. The better lenses, though, will generally last longer under heavy use simply because they are better built for a lot of use. They also typically focus faster when using autofocus. I suspect that low-priced consumer-grade lenses may be more prone to flare and other image quality degradation (than the "L" series) when there are bright light sources impinging directly on the front lens element, but I have not tested this.

A huge difference (for me, at least) between lenses like the two you compared is the fact that front end of the 55-250 rotates (I believe when focusing) and that can be a problem if you are using a polarizing filter. Because a polarizing filter has to be rotated to the right position for the desired effect, it is a bad idea to have the lens' front end rotate because that mean you'll have to readjust the filter and doing that could affect focus, etc. The "L" lenses do not have rotating front elements.

The only lenses I have for my 20D are all "L" class lenses. They all perform just great.

All very excellent points. While my use may not be high enough to warrant L's, the other things you mention make them worth considering. I've already experienced another need: being about to have it auto focus, but tweak manually w/o turning off the AF.

56_kruiser wrote in post #12145890
I was speaking with a friend, and he said he has spoke with someone at a local camera shop and asked about an L lens on his small format camera. He was told that on that type of body, an L lens is not particularly a good idea.

56_kruiser wrote in post #12146959
One thing I have done related to this topic: I have a 70-200 2.8 Ultrasonic L non-IS lens in my possession for a couple weeks.

Yesterday, I went out front and took some pictures with that lens, and my 55-250 F4-5.6 IS lens. I was wanting to compare pictures. So I set up to take the exact same photo, changing lenses to get it again, with both set at f.4, and 70mm, during the afternoon.

I then put the photos on my computer and tried to compare. Zoomed in to look at it extremely close; I compared the exif information. Studied color, and detail.

Frankly, about all I could find for difference was that the L lens, with its larger lens diameter, took the same picture quicker. Did it several times, and found in one example, mine took it in 1/500, the L did it in 1/1000; another time mine 1/1000, the L 1/1250. I"m new enough to this that I thought maybe mine may look a bit grainy in comparison, but that didn't seem to be the case.
I realize of course the quality material differences, but my questions and concerns, at this stage in my photography excursions, is quality of picture.

right, a lot of times "L" lens on a 1.6 crop don't seem all that spectacular.
Hmmm... maybe that "moron" camera salesperson is on to something ...

If anything, wouldn't using a L lens on a crop be "better" than a full frame? The rationale is that the light that falls onto the sensor will be from the center of the glass, eliminating the corners, thus producing a "sharper" image. However, this effect is insignificant because we're talking about an L lens. Would anyone like to elaborate on it? Just a thought.

turkleten wrote in post #12148769
If anything, wouldn't using a L lens on a crop be "better" than a full frame? The rationale is that the light that falls onto the sensor will be from the center of the glass, eliminating the corners, thus producing a "sharper" image. However, this effect is insignificant because we're talking about an L lens. Would anyone like to elaborate on it? Just a thought.

sorry, no.
See the "MTF" image resolution data comparisons on the same camera with "L" and other similar focal length EF-S lens at www.photozone.de

Good call on the MTF; I completely forgot about that! Someone posted this a idea months ago and for some reason, I found it plausible so it stayed in my mind lol. Thanks for clearing that up!

Velorium wrote in post #12147065
If you're debating about 50mm's, the Sigma 50mm f/1.4 is much sharper than the Canon 50mm f/1.4 for a similar cost.

I'm not beginning to think about a 35 instead of 50.

Some reviews I've read, on the Sigma 35, indicate alot of focusing problems with the Sigma.

I think I'll try renting a couple to see how the go for me.