28-135mm EF vs. 55-250mm EF-S, please help me understand crop factor.

[klavender]

Sorry for the newbie question but I've searched Google and couldn't really understand this. I have a 40D with a 28-135mm EF lens. I understand this is a APS-C camera and since the lens is an EF that the effective zoom is 44-216mm. I would like to get more zoom but the EF-S telephoto is 55-250mm. 250mm doesn't seem like much more that 216mm and I'm not sure it's worth it. I've also looked at the EF 70-300mm which would be 112-480mm. It's twice as much money and would think I would want it slightly wider at the low end.

Also, if I go with the EF-S 55-250 would the STM be worth it over the standard? I want a quick focus as this will be used mainly for wildlife. How does the standard and STM compare to the USM of my current lens?

[ebiggs1]

"Chestnut-sided Warbler, just a slight crop for composition. Canon 7D Mk II, Sigma 120-300 f/2.8 w/ 2X TC at ~550mm."

Very nice shot Tom Martin.  And I love the Sigma 120-200mm f2.8. It is a great lens and hadles the tele converter well.  One of the few that do.  I used that combo for a long time until I got the big Siggy 'S'.

It on the Mk IV is wonderful.

[klavender]

Just a very quick shot with my new lens. It came in, slapped in on the camera and sat on the front porch. This little guy landed on the power line so I took a couple of quick hand held shots. Overall I'm happy with it. I couldn't crop much more than this without it getting grainy. Weird part is, I've never seen this kind of bird before. It appears to be a Lazuli Bunting. Anyways, was shot at f/5.6, 1/80, ISO 100 at full zoom.

[TTMartin]

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@klavender wrote:

Just a very quick shot with my new lens. It came in, slapped in on the camera and sat on the front porch. This little guy landed on the power line so I took a couple of quick hand held shots. Overall I'm happy with it. I couldn't crop much more than this without it getting grainy. Weird part is, I've never seen this kind of bird before. It appears to be a Lazuli Bunting. Anyways, was shot at f/5.6, 1/80, ISO 100 at full zoom. 

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Well if that wasn't resized after the crop, it looks pretty good to me even at 100%. Shutter speed might be a bit low, since birds tend to fidget. The background out of focus area has a nice quality too. STM lenses are such a bargain. 

[klavender]

Shutter speed is something I need to consider next time. I mainly just try to make sure the light meter is in the middle. I was just thinking, "wow, what kind of bird is this?". Haha.  Was really impressed with the background blur. Not bad at all for a $130 lens!

[Waddizzle]

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@klavender wrote:

Shutter speed is something I need to consider next time. I mainly just try to make sure the light meter is in the middle. I was just thinking, "wow, what kind of bird is this?". Haha.  Was really impressed with the background blur. Not bad at all for a $130 lens!

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Yes, shutter speed is something to bear in mind.  But, I think ISO 100 is what pulled the shot across the burning coals.  It is easy to get background blur [a.k.a. BOKEH] with long focal lengths focused on relatively nearby subjects.

http://www.dofmaster.com/doftable.html

Depth of Field is what creates background blur. Perfect focus is at a fixed distance from the lens.  However, there is a range of distances, DoF, behind and in front of the perfect focus plane that the human eye recognizes as acceptable focus.  This range of distances is depth of field.  It varies with focal length, sensor size, and distance to the subject.

[TTMartin]

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@Waddizzle wrote:

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@klavender wrote:

Shutter speed is something I need to consider next time. I mainly just try to make sure the light meter is in the middle. I was just thinking, "wow, what kind of bird is this?". Haha.  Was really impressed with the background blur. Not bad at all for a $130 lens!

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Yes, shutter speed is something to bear in mind.  But, I think ISO 100 is what pulled the shot across the burning coals.  It is easy to get background blur [a.k.a. BOKEH] with long focal lengths focused on relatively nearby subjects.

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The quality of the background blur is what I was talking about. Nice and smooth with well rounded highlights. There is more to it that it simply being out of fosus.

[Waddizzle]

"The quality of the background blur is what I was talking about. Nice and smooth with well rounded highlights. There is more to it than it simply being out of focus." 

Yes, of course.  The aperture blades help shape it.  No need to make too many waves, not just yet.  The lens has very nice bokeh.

[ebiggs1]

In spite of all the relevant or irrelevant chit-chat, that is a Eastern Blue Bird.

[RobertTheFat]

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@ebiggs1 wrote:

In spite of all the relevant or irrelevant chit-chat, that is a Eastern Blue Bird.

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I thought he looked like a barn swallow. But one thing I'm not is a bird photographer, so I'll defer.

[Waddizzle]

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@RobertTheFat wrote:

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@ebiggs1 wrote:

In spite of all the relevant or irrelevant chit-chat, that is a Eastern Blue Bird.

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I thought he looked like a barn swallow. But one thing I'm not is a bird photographer, so I'll defer.

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Wow, I just looked up "eastern bluebird" and "barn swallow, and, boy, do they look alike!  But, the eastern bluebird has more of that white breast and belly than the barn swallow does.  I think Ernie's right.

All of which just makes me wonder, what is this critter?

I was thinking it was a "blue jay".  I'm no bird photographer, either.  But, it's a fun as fishing, at least to me.