Question about inexpensive lenses

I have a question about some lesser expensive lenses I see from Canon, Sigma and Tamron. I am sure there are many differences between these and the better grade lenses and it is obvious that they are not fast lenses, so that leads me to this.

Assuming you were going to buy a dedicated lens for working on indoor portraits where you had more than enough light and lots of control over that light could you get away with one of these lesser expensive lenses because lens speed is not an issue to get the exposure and shutter speeds you want, even at lower ISO's? Is there more to an inexpensive lens that seperates it from other lenses in the product line that are faster, thus more expensive? Does build change?
Ultimately I am trying to determine if any of these lenses are worth considering for dedicated application lenses. Who is buying these lenses and what are they being used for? Can they produce sharp images? ( I know, lots of questions)... Is the fact that it is not a fast lens going to inhibit the ability to get good bokeh on portraits? of will using it wide open give me good results?

Hi Robert,

There is more to a lens than its speed ... build quality, variable vs. constant aperture throughout zoom range, AF speed, centre vs. edge sharpness at different apertures, chromatic aberration control (aka purple fringing), flare control, bokeh are just the ones I can think of.

For indoor portraits you could, for plain portraits, get away with a cheap lens that performs well around f/8, but this will limit what you can do with depth of field. But for indoor portraits you can zoom with you feet and pick up a good prime like a 50/1.4 or a 85/1.8, both of which are fast and deliver well on most of the areas I mentioned. They're a bit pricier than the bottom-end lenses but a lot cheaper than L-series equivalents.

Hope that helps.

With lenses, you get what you pay for. The 50mm f/1.4 would likely be the best bang for your buck in terms of price and image quality.

I figured that no one would recommend them. Just needed to know why.

Regarding the 50mm f/1.4 , would that be a Canon or is there another one to be looking at?

linarms wrote in post #2100012
Hi Robert,

variable vs. constant aperture throughout zoom range,

A little OT, but I'm curious-- how does this factor in when you try and manual expose? I was just thinking about the fact that I haven't really shot with a variable aperture lens for like, 8 months now (first cheapo primes and now L zooms), and in the interim have really started using manual more. Is it possible, or is it a huge pain? Just wondering.

Yep, the 50mm f1.4 is a Canon EF lens. If you consider this focal length, I recommend to look also at EF 50mm f1.8 lens - much cheaper (built like a kid's toy) but also great optically.

Regarding the original question - I guess that if you buy some lower-tier lens (say the 18-55 EF-S kit lens) and use it at f8, you still would get very decent results. The build quality matters in situation when you need your equipment to be built very well - I guess that this is not the case when we are talking about shooting in a studio.

Using these lower-tier lenses wide open will degrade the sharpness of your pictures to a certain degree and also may introduce some other undesired effects (color abberations, vignetting etc). These effects are more pronounced with some lenses and virtually non-existent with others - you have to consider each case individually. There ale lots of tests and review for almost every existing lens - just type the name of the lens + a word "review" in Google. And yes, shooting at wide apertures will decrease your depth of field and blur the backgroung more.

There are lots of great lenses which produce exeptional results at very fair prices. Just name your desired focal length and we will be happy to spend your money for you in the best possible way

tsaraleksi wrote in post #2100145
A little OT, but I'm curious-- how does this factor in when you try and manual expose? I was just thinking about the fact that I haven't really shot with a variable aperture lens for like, 8 months now (first cheapo primes and now L zooms), and in the interim have really started using manual more. Is it possible, or is it a huge pain? Just wondering.

With variable aperture you will have to calculate your exposure according to every aperture value. I myself don't use manual exposure mode, I find it to uncomfortable. I use Av mode almost exclusively - set the aperture and the camera does the rest (sometimes I compensate the exposure according to the scene).

For manual exposure I don't think there is any advantage of one lens over another. The procedure is the same regardless focal length, aperture, or ISO. It's easier to make an error when making all adjustments manually, but that's simply because the camera is not doing as much work for you. It isn't difficult at all. I would still want the fastest lens I could afford. Even on a tripod you get crisper images with faster shutter speeds.

In a studio you can theoretically use anything since you will have easy focusing with the modelling lamps or overhead lighting (which would be drowned out by the studio strobes).

However, since you have total control over the scene and can zoom with your feet very easily, even an inexpensive yet good prime would be better than a kit lens or similiar. Higher IQ, more DOF control, etc.

tsaraleksi wrote in post #2100145
A little OT, but I'm curious-- how does this factor in when you try and manual expose? I was just thinking about the fact that I haven't really shot with a variable aperture lens for like, 8 months now (first cheapo primes and now L zooms), and in the interim have really started using manual more. Is it possible, or is it a huge pain? Just wondering.

Having to rethink your aperture when you're shooting wide open and then decide to zoom in is definitely a pain.