Beginner Prime lens help

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rod james

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Hi

I am just embarking on getting a prime lens and considering my small budget I am thinking of getting either Canon 24mm F2.8 pancake or Canon 50mm F1.8. Was just wondering what your preference would be or any tips to persuade me to one lens or another?

Thank you
 
What camera do you have?

If you have a short zoom lens that covers both of those focal lengths you can set it to either of those and use it like that for a few days, then switch it to the other for a few days to see which you like best..
 
I often wonder if f2.8 primes are worthwhile when we have good f2.8 zooms.

f2.8 primes may be worthwhile if they're cheaper, more compact and lighter than a larger but more flexible f2.8 zoom, if they're simply better or if you just like the particular look the lens gives.

If cost, bulk or the look aren't major factors maybe a more flexible f2.8 zoom could be a better option.

I don't know what your priorities are but I'd be much more tempted by a f1.8 prime than a f2.8 unless cost, bulk or look were my priorities.

Anyway if the choice is 24 or 50mm on APS-C I'd probably go for the 24 and on FF I'd probably go for the 50mm.
 
rod james said:
Hi

I am just embarking on getting a prime lens and considering my small budget I am thinking of getting either Canon 24mm F2.8 pancake or Canon 50mm F1.8. Was just wondering what your preference would be or any tips to persuade me to one lens or another?

Thank you
Click to expand...

Welcome to TP :)

Why do you want a prime lens? What do you want to do with it? Those two lenses are very different.

Primes have a few advantages, and disadvantages of course, but the main one - the thing primes can do that zooms cannot - is run very low f/numbers like f/1.4. That's good for low light working and for producing shallow depth-of-field effects. Primes are usually smaller and lighter, often cheaper, and optical performance high.
 
woof woof said:
I often wonder if f2.8 primes are worthwhile when we have good f2.8 zooms.
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Totally agree Alan. The only advantage of the 24mm 2.8 is the size compare to let's say a sigma 17-50 f2.8 which are not that expensive and cover this focal lens at the same aperture.

On a crop sensor the 50mm 1.8 makes a nice lens for portrait. You will get much shallower depth of field and can be a bit creative. Plus you have the advantage of the f1.8 for low light.
 
Like others have said, the information that's best for helping with your query is what you want to use the prime lens for and what type of camera you have I.e. Crop sensor or full frame.
 
Wow. Thanks Guys

My camera is a Canon 100D which has a cropped sensor. I would like a lens to take landscapes and shoot at night and my budget is very tight at around £150. It would be £0, if my partner had their way as they are not a fan of me "leaving the house in the middle of the night, like some undercover spy" LOL
 
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rod james said:
Wow. Thanks Guys

My camera is a Canon 100D which has a cropped sensor. I would like a lens to take landscapes and shoot at night and my budget is very tight at around £150. It would be £0, if my partner had their way as they are not a fan of me "leaving the house in the middle of the night, like some undercover spy" LOL
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In that case your best bet would be to get a used Sigma 30mm f/1.4

It's the perfect focal length for the crop sensor on the 100D and the wide aperture is exactly what you need for low light shots.
 
keenan said:
In that case your best bet would be to get a used Sigma 30mm f/1.4

It's the perfect focal length for the crop sensor on the 100D and the wide aperture is exactly what you need for low light shots.
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This

Unless you're wanting to shoot the sky, then you will want something wider. But wide fast primes are expensive.
 
If I can find the Sigma 30mm 1.4 in my price range, I'll go for that. If not then it will be the canon 24mm 2.8
 
Omg. Now I've read the Sigma 30mm 1.4 HSM suffers from auto focus problems, yikes ... The newer version is way over my budget
 
rod james said:
Omg. Now I've read the Sigma 30mm 1.4 HSM suffers from auto focus problems, yikes ... The newer version is way over my budget
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Some do indeed have back or front focussing issues. Sadly the 100D also doesn't have micro focus adjustment.

Your next option would be to look at the 50mm f/1.8 STM.

Or if you really want a wider angle of view also look at the Yongnuo 35mm f/2, but at this point you might be better off with a Tamron 17-50mm f/2.8 or to rather just take a gamble on the Sigma..
 
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rod james said:
Omg. Now I've read the Sigma 30mm 1.4 HSM suffers from auto focus problems, yikes ... The newer version is way over my budget
Click to expand...

I've used both the older Sigma 30/1.4 and newer Art version, no problems.

If you google enough, you'll find problems of some sort with pretty much any lens. Sigma often gets more than their fair share of complaints simply because they sell a lot of lenses, across both Canon and Nikon and other brand users.
 
woof woof said:
I often wonder if f2.8 primes are worthwhile when we have good f2.8 zooms.
Click to expand...

I shoot almost exclusively with primes these days.

For myself, I prefer to anticipate exactly what I will see in the viewfinder before I bring the camera to my eye. I find it's easier to consider the framing when my mind is thinking in terms of a specific focal length.

Look first, look well, then compose. A zoom tends to complicate that - it makes for too many possibilities that I have to consider while looking.
 
Musicman said:
I shoot almost exclusively with primes these days.

For myself, I prefer to anticipate exactly what I will see in the viewfinder before I bring the camera to my eye. I find it's easier to consider the framing when my mind is thinking in terms of a specific focal length.

Look first, look well, then compose. A zoom tends to complicate that - it makes for too many possibilities that I have to consider while looking.
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I disagree.

With a zoom you can get confused and stand in one spot zooming in and out but if you stop panicking and engage your brain and realise that zooming in and out changes the framing but not the perspective and that changing your camera to subject distance affects the shot greatly then a zoom becomes a very long list of prime lenses.

As an example, I have a Panasonic 14-42mm Mega OIS (FF equiv of 28-84mm) and it's the size of a prime lens. The only drawback is its rather pedestrian aperture range of f3.5-5.6 but for good light shooting it's effectively a 14mm f3.5 prime and then a sliding aperture scale to a 42mm f5.6 prime. That's a very handy tool to have.

Walking about until you're in the right position and at the right distance from your subject and then making minor framing adjustments with a zoom is a perfectly valid way of using them.

I mostly use primes myself but it's for reasons of aperture and packaging as primes often have apertures unmatched by zooms and can also be more compact. Personally I only consider f2.8 and smaller primes if they fulfil a specific need such as for macro, like a 50mm f2.8, or for reasons of packaging such as my Sony Zeiss 35mm f2.8 which is tiny and makes for a very good and discrete camera and lens package.

If that Panasonic 14-42mm was f1.x throughout it's range and did macro it might just be the only lens I'd need.
 
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rod james said:
.......If not then it will be the canon 24mm 2.8
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If you are talking about the pancake one, the EF-S 24mm f/2.8 STM then I dont think you would be disappointed, cracking little lens, especially for the money.
Given your intended use though, there is one possible drawback to it. The focussing is of the fly by wire type, which if you are shooting stars, cant be pre-focussed at infinity, you will need to focus it manually, unless you have a far off light source to auto-focus on.
Other than that it is quick, accurate and silent to get focus, brilliant for video too.
 
HoppyUK said:
Welcome to TP :)

Why do you want a prime lens? What do you want to do with it? Those two lenses are very different.

Primes have a few advantages, and disadvantages of course, but the main one - the thing primes can do that zooms cannot - is run very low f/numbers like f/1.4. That's good for low light working ...
Click to expand...
Actually, that isn't really the case. The micro lenses over the sensor have their own aperture which tends to be around f/2.8-4, so the sensor doesn't actually get more light at wider apertures. And the smaller the lenses (pixels) are, the smaller their aperture tends to be. What the camera does is increase the amplification (ISO) in order to keep the exposure correct, but you have no way of knowing when/how much... it's not reported.

This is an older article, but I'm not aware of any changes to the technology applicable. They also do not explain "why" it happens... but it's pretty much exactly the same reason you can't see DOF wider than ~ f/2 with wide aperture lenses (the focus screen's aperture is ~ f/2).
 
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sk66 said:
Actually, that isn't really the case. The micro lenses over the sensor have their own aperture which tends to be around f/2.8-4, so the sensor doesn't actually get more light at wider apertures. And the smaller the lenses (pixels) are, the smaller their aperture tends to be. What the camera does is increase the amplification (ISO) in order to keep the exposure correct, but you have no way of knowing when/how much... it's not reported.

This is an older article, but I'm not aware of any changes to the technology applicable. They also do not explain "why" it happens... but it's pretty much exactly the same reason you can't see DOF wider than ~ f/2 with wide aperture lenses (the focus screen's aperture is ~ f/2).
Click to expand...

The problem though Steven, is that reality contradicts this, and faster lenses down to f/1.4 etc do actually result in brighter images. They don't follow the f/number in an exactly linear fashion, but they never have done - it's not so much of a digital/pixel thing but T/stop and vignetting related. Also, if the pixels were behaving as you describe, then not only would you not see increased brightness at f/1.4, you wouldn't see shallower DoF either. There are some off-axis issues with pixel light gathering, but these are mostly eliminated with off-set micro lenses and other aspects of sensor design and are in any case much less than optical vignetting, and easily corrected in post-processing.

Also, to measure these things accurately, tests must be made at infinity focus. Shooting test targets at close distance will inevitably lead to wrong conclusions.
 
HoppyUK said:
The problem though Steven, is that reality contradicts this, and faster lenses down to f/1.4 etc do actually result in brighter images....
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It's a simple fact of physics... a lens of any sort has an associated (max) aperture, and that means it has a max transmission capability. But one thing to note is that aperture is not a hard limit, it's essentially a "percentage rating." I.e. if the primary lens projects more light at a wider aperture the micro lens will also transmit more light, just not all of it if it's aperture is smaller/more restrictive.

The difference between the focus screen and the sensor's micro lens array is that the focus screen is a single lens (essentially a fresnel lens). Because it is a single lens it has it's own aperture which limits both the minimum DOF *and* max light transmission. This is also true of the AF module which typically has an aperture of approximately f/7 in terms of light transmission/DOF (per lens/ AF area).
But the micro lens array is not functioning "singularly." Even though each has it's own aperture which limits light transmission per pixel, it does not limit DOF *per image*... the DOF per image is a matter of what falls where, not how much (similarly, SS does not affect DOF).

The image does indeed record brighter at wider apertures, but that is largely due to unreported amplification which is required in order for the exposures to follow the convention of film... I understand the f-stop and t-stop (ratio) are relative to the FL which is only (kind of) accurate at infinity focus where FL is determined/measured. But even if that isn't accounted for the relative light losses measured, and the increased gain measured means that the appropriate amount of light is not reaching the sensor (i.e. you couldn't use the loss to determine an accurate t-stop rating, but it's still real). This is separate from t-stop/vignetting and only applies to digital.

I do know that, in general, there have been improvements made in micro lens arrays/fill factor... so maybe no modern camera sensor (pixel) is limited to f/4 as the D200/7D are in those tests. But I doubt the issue has been entirely corrected because it seems like at the same time they increase efficiency they also keep increasing MP's... maybe one is only allowing the other w/o making things actually worse?

None of this affects any of the other aspects of the fast prime on digital (construction/sharpness/DOF/etc)... but it is kind of messed up IMO. Probably best to put it in the category of "I can't change it, so there's no point in worrying about it."

Edit: I suppose my initial statement was a bit misleading/incorrect... I did say "the sensor doesn't actually get more light."
OK, entirely incorrect....
 
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My 2 cents is this...
I have a 4 lens full frame zoom set and a 3 lens lens ASP-C set...and a set of primes.
For most of my shooting I use the full frame zooms, sometimes I take the ASP-C set out as it's smaller, lighter and compact but sometimes I take my primes because I enjoy shooting with primes, not because of the IQ or compactness or lightweight or small size but I just enjoy shooting with primes.
With primes you adopt a different approach to zooms and i enjoy the change. You have to consider the shot more, which prime shall I pick? then move about to get the composition.
I use primes when I'm on my own not with mates and I enjoy it, but you have to be in the right frame of mind and in the right location and i find that extra bit of effort and consideration can result in photos you would have never got using a zoom, really good photos so it's worth it and it's fun.
 
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