My camera came bundled with a Canon 18-55 mm IS STM lens. Is this a very basic or generic lens? My current problem seems to be that my photos just look like very superior cell phone photos. Is it my settings or my lens?
What lenses would you all recommend for portrait, close ups, and landscape?
I am learning as I go. I have no mentors or training at this time, any help is appreciated. I am basically reading articles and watching YouTube videos.
The 18-55mm kit lens is designed to be an affordable way to get started.
I'm reading between the lines and guessing you were hoping for the portrait effect where you have a sharp subject, but a softlly blurred background ... and this helps the subject pop.
To do that, you need a shallow "depth of field". The "depth of field" (usually abbreviated as 'DoF') is the range of distances at which a subject will appear to be in acceptable focus. E.g. if you have a subject 10' away and you focus on them, the reality is that things 9' away and 11' away are probably also in focus. But maybe subjects 2' away and 50' away are NOT in focus (when the camera is focused for 10' distance). So there's some range where focus is acceptable (even if not perfect).
This range (the DoF) is controlled by three factors, but the lens choice influences two of those three factors.
Those factors are (1) distance, (2) focal length, and (3) aperture (aka focal ratio).
Depth of field naturally gets broader as you increase the focus distance. So you'll have more DoF if your subject is 100' away then you would have if your subject were merely 3' away.
Wide angle lenses (lenses that have a short focal length... say 10mm) has a very broad DoF. Very long narrow-angle lenses (say 300mm focal length) will naturally have a somewhat shallow DoF.
The lens is able to increase or decrease the opening through which light can pass through the lens by constricting or dilating aperture blades. The larger the aperture, the shallower the depth of field. The aperture isn't expressed as a fixed size (such as 5mm wide or 10mm wide) it's expressed as a ratio. That ratio is found by dividing the focal length of the lens by the diameter of the aperture. E.g. if I had a 100mm focal length lens and my aperture was 25mm wide, then 100 ÷ 25 = 4. So this ratio is 1:4 and is usually abbreviated/written as f/4 (f/__ means "focal ratio of 1 over ____") It turns out when the focal ratio value is a high number (e.g. f/16 or f/22) then that means the aperture size is actually very small. If the focal ratio value is very low (e.g. f/1.4 or f/2.0) then that means the aperture size is actually rather large (but it's all relative to the lens focal length).
I own a 14mm f/2.8 lens. f/2.8, for many lenses, is a "low" focal ratio. This might suggest I'm getting a very shallow depth of field. BUT... 14mm is a very short focal length and short focal lengths naturally have a very broad depth of field. It turns out if I use this 14mm lens to take a photo of a subject merely 5' away ... even at f/2.8... my background has very little blur.
I also own a 300mm f/2.8 lens. Using that same f/2.8 focal ratio... If I take a photo of a subject... even at some considerable distance (say 50' away) I still get quite a strong amount of background blur. This is because the 300mm focal length creates a shallow depth of field.
Canon makes an 85mm f/1.8 lens which is reasonably priced and it can produce a pleasantly blurred background for portraits. Canon also makes a brand new version of this lens with an f/1.4 focal ratio (and that lens also has image stabilization) which can produce even more background blur. There's also an f/1.2 version (very expensive).
I should caution you on the prices...
You'll find that ultimatley what it takes to get that background blur is a long-ish focal length (preferably 85mm or longer but you'll even get a bit of it at 50mm and if you really work at it, you can even get it at 35mm... but the longer the lens, the easier it is) and ALSO a low focal ratio (preferably f/2.8 or lower... but the shorter the focal length, the lower the aperture needs to be to get as much blur... at 85mm it helps to have f/2 or lower. At 35mm it helps to have something like f/1.4.)
But since the focal ratio is really a ratio relative to the focal length, it means the diameter of the lens has to be PHYSICALLY larger. Since the glass is physically bigger in diameter, it's also thicker. Thicker glass is heavier. The glass acts like a prism and tries to sepearate light into it's different wavelengths and this creates color fringing near the edges of the frame (it's why you notice if you hold a magnifying glass in front of a page of black & white print, you see colors bleeding out of the "black" text near the edges of the magnifying glass). To control this undesirable problem, Canon has to add more corrective glass elements inside the lens ... making it even heavier still. It's also desirable to use extra-low dispersion or ultra-low disperion glass (ED or UD glass) which costs more than regular optical glass. Canon sometimes even uses flourite crystal (which has to be "grown" in a kiln and can take months to grow a batch).
This is a very expensive way to make the glass suitable for use in these lenses ... and that means the lenses aren't cheap.
You can get the Canon EF 85mm f/1.8 on sale right now for about $350. That's a pretty good bargain.
The 85mm f/1.4 IS USM is about $1600 (not on sale... it's a new lens, it's in very high demand, and it has image stabilization)
The 85mm f/1.2 USM is about $1850 (on sale... normally about $2000).
So there's quite a dramatic price increases as you try to get even just slightly better focal ratios. For this reason most people just go with the f/1.8 version ... which does quite a nice job. Sure, the f/1.2 would be better... but you can buy five f/1.8 versions for the price of just one f/1.2 version.
If you want to see examples, I'd suggest visiting Pixel Peeper: https://pixelpeeper.com/lenses/canon/
Pixel Peeper actually just indexes the images that have been upload to Flickr (their requirement is the lens data and shooting info must be included with the image.) This way you can select a lens and see loads of examples of images shot using that lens. You can pick the camera & lens combination to show only examples of cameras with APS-C sensors (like your new T7i) with the lens you are thinking about getting. You can even tell it you only want to see images shot at a specific focal ratio (or range of focal ratios).
Landscapes are much easier because this is an area where you typically want a moderately wide angle of view and a very broad depth of field... which is exactly what your kit 18-55mm lens already does.
I've done landscapes with longer focal lengths... but most of the time a landscape photographer reaches for something with a midly wide angle of view (sometimes dramatically wide). And they almost always want a very broad depth of field.
ONE MORE THING
How you "adjust" the image will have a big influence on how good it looks. It's a good idea to learn about shooting in RAW (instead of JPEG), and learning to use software to apply adjustments. This allows you to have control over white balance (color cast), exposure, highlights, shadows, color saturation, etc. etc.
My other half primarily uses his phone to take photos. They used to all look pretty flat, until I showed him how to adjust the images. Now they look MUCH better (same "camera" ... just learning better processing made all the difference.)
The camera isn't magic. You wont be a fabulous photography just by owning a better camera any more than you'd be an olympic athelte because you bought better running shoes. The camera is just a tool. Getting a better result is mostly about your own skill.
Landscape. Landscape is largely a matter of subject choice and composition. I'd look at info on composition rules for that. Your current lens should be ok.
Closeup. How close? Like a bug's eye, or not so close? True closeup is a bit of a specialty if that is what you mean.
Portrait. Tim is right I suspect in guessing you are looking for a shallow depth of field in focus, and a nice blurred-away background. A 50mm f/1.8 STM would do a good job for only about $110.00.
You can, however, get that shallow DOF with your lens.
a.) Lowest f/number possible. Low f/number means large lens opening means shallow depth of field. Put the camera in Av (aperture value) mode on the top mode dial. Select the lowest f/number. The 50mm f/1.8 lens I mentioned above would let you select a huge f/1.8 lens opening, and would really isolate your subject well.
b.) Camera close to subject. DOF is shallower up close. Get up close to the subject.
c.) Background as far back as possible. The out of focus background blur effect increases the further the background is away from the in-focus subject. If your subject is leaning on a wall and you are shooting straight-on the wall isn't going to be blurred much if at all. If your subject is standing 20 feet in front of the wall the wall can be very blurred.
d.). Zoom in, not out. A longer (zoomed in) focal length gives shallower depth of field than a wide angle (zoomed out) focal length. Zoom your lens in to 55mm, not out to 18mm.
Here is a link to a DOF calculator.
It is an old application, so the latest cameras are not listed. Bit, sensor size is what matters, so any APS-C Canon would be the correct camera to use, like the 70D.