Got my firs dSLR + Noobish Questions!

doomhart · Oct 16, 2010

I finally got a dSLR! Canon T2i + 18-55 IS EFS Kit lens and the 55-200 IS EFS lens that's $300 and i got for $100! So body + 2 Lenses= $1000. Is that a good deal at Best Buy?

So here are my questions:

1) So EFS are made for 1.6x crop factor sensors, and EF is made for full frame? Is that right?

2) If my understanding of 1) is right, then are EFS focal lengths already calculated for 1.6x sensors? And EF lenses mean that I need to still calculate them? For example, on the widest focal length, an 18-55 EFS would be 18mm but an 18-55 EF would be about 30mm? Is this right?

3) I've been shooting on nothing but manual this past week. This is the first time I have a camera that go on manual, and the first time I'm using a manual camera for more than 5 minutes.
Heres my manually-taking-a-picture-step-by-step list:
1. Look for a subject
2. If subject is found, look into viewfinder
3. Compose, half press shutter, focus on the desired spot go to manual focus if auto cant get the desired focus spot
4. Check meter
5. Adjust shutter speed, aperture, ISO to get desired exposure
6. Press shutter button completely

So, is this flow ok? Am i missing anything? And what is YOUR step-by-step?

Sorry for the long post!

I hope somebody answers the questions so i can get better!

GooniesNeverSayDie11 · Oct 16, 2010

If thats all you are doing, then there isn't much point to shooting on manual, other than wasting your time and letting photo ops slip by. Shoot in Av or Tv mode and set one. For example, if shooting sports, use Tv and set a fast shutter speed so you are ready to fire. Or if going for a defocused background portrait, use Av and set a low aperture and let the camera choose the speed. Manual is good for learning what will be needed in various situations or when using non-ttl flash, or when you want specific effects like a blurred background when panning, etc. If all you want is a correct exposure, manual is a waste. Everyone acts like its some right of passage. :sexywink:

As for EF-S, the focal lengths are still the same as on EF lenses. The real reason I believe that they will not fit on a full frame camera is because the mount design will hit the mirror ( I am pretty sure, but others can verify ) I had heard of people modifying them to fit, but cant verify that.

As for the package you got, thats not a bad price for an entry level set up like that. You can get them for about $1000 on ebay ( but wouldn't have had to pay sales tax, unless Hawaii doesn't have any ).

peacock · Oct 16, 2010

You're misunderstanding the concept of focal lengths. Firstly, focal lengths of lenses don't change from what is stated. So if a zoom lens says 18-55mm, the focal length would always be 18-55mm. You don't times that by 1.6 or anything, that's a common misconception. What you're trying to find out instead is the FOV - the field of view, basically how 'wide' is your shot. Since, with cameras with smaller sensors (like cameras that use EF-S), when putting on ANY lens (any means including EF and EF-S), it would have a smaller FOV (so picture would be zoomed in more) than the picture taken with a full-frame sensor using the SAME lens.

So my answer to your 2nd question, the lens is what it is stated. Whether it is EF or EF-S lens, if it says 200mm, it is 200mm. The physical length of the lens does not change. However, if you use a lens (let say 55mm) on small-sensor camera, the picture would look more zoomed in than if the lens was used on a full-frame sensor.

IF you want to compare the 'crop factor' or 'zoom factor' of your final picture, then you would need to do some calculations. In your case, since you got an APS-C size sensor camera, the crop factor would be 1.6x (as you rightly said). This means that if you use a 100mm lens on an APS-C sensor, the picture would look like it was taken with a 160mm lens on a full-frame sensor.

On your 3rd query, there's really no need to use manual for general photography. You only use it when other modes does not serve you well enough, such as taken pictures of smoke with a speedlight in a pitch dark room. Also, manual requires you to adjust both aperture and shutter speed for you to get the right exposure (sometimes even ISO if both aren't enough). Unless your subject won't move until the next day, then manual would be fine if you have too much free time. Otherwise, modes such as Tv and Av are quite useful to play with, since they offer you control of either shutter speed OR aperture, while automatically maintaining your selected exposure by adjusting the other. The method you said you used for manual can be done by P mode in less than a fraction of a second.

GooniesNeverSayDie11 · Oct 16, 2010

peacock said:
You're misunderstanding the concept of focal lengths. Firstly, focal lengths of lenses don't change from what is stated. So if a zoom lens says 18-55mm, the focal length would always be 18-55mm. You don't times that by 1.6 or anything, that's a common misconception. What you're trying to find out instead is the FOV - the field of view, basically how 'wide' is your shot. Since, with cameras with smaller sensors (like cameras that use EF-S), when putting on ANY lens (any means including EF and EF-S), it would have a smaller FOV (so picture would be zoomed in more) than the picture taken with a full-frame sensor using the SAME lens.

Actually, he is quite rational in his thinking. If the lens CAN'T be used on a full framed sensor, then it essentially is ALWAYS the cropped sensor distance. So you can't really say that its any other focal distance. I think Canon simply does it for consistency since most people just automatically apply that crop factor when buying a lens. The lens physically covers the specific areas, but due to the sensor size its as if you zoomed in or cropped (hence the name ) but for all practical purposes, it becomes a longer lens. If you simply cropped, you would be throwing away resolution, but since that "crop" is the cameras native size, you are not throwing away detail or whatnot like a real crop would do. So essentially, at 200mm you would be getting the same image you would see at 400mm on a canon full framed camera. You can argue about the technical jargon all day, but all it does is confuse people. The right way to think about it, is the practical way that effects your shooting. If you need to get as wide as you can get you aren't going to get a 17mm that is the widest canon L lens because its super wide on a full frame. You are going to shoot for something in the 10mm range, because thats a practical effect on the shooting you are attempting to do. Don't clog your brain with useless nonsense :mrgreen:

Vinny · Oct 16, 2010

My suggestion is to set your camera on the lowest native ISO and adjust it only when the shutter speed and aperture aren't able to give you the desired effect that you're looking for. You need to set your aperture for the desired depth of field you're looking for and set your shutter speed to at least 1/focal length to get sharp photos when the camera is hand held.

There is the "correct" setting and there is the "artistically correct" setting which can be different. I disagree on not to shoot fully manual. Yes, the automatic mode (I like to shoot in aperture priority when I do) is helpful but knowing how to shoot fully manual is important to get "artistically correct" photos.

I think that the whole focal length naming is based on full frame sensor (35mm film). It would get a little confusing to name a certain lens a different focal length for crop sensors vs full frame. Full frame lenses can be used on crop sensors and I believe crop sensor lenses can be used on some cameras - either the edges aren't there or the camera treats the sensor as a crop sensor internally.

doomhart · Oct 17, 2010

Thanks Vinny, Goonies and peacock for replying!

Whaaaaaaat? So manual isn't a right of passage? Gaaaah i wasted a $1000! Just kidding, just kidding. @Gooniesandpeacock i understand what you mean, my bad i forgot to mention for almost every shot i also care for DOF, blur and grain. So does that make up for the worthiness of manual? Oh, and i am also attracted to the ways of the old school people hahahah. So im probably gonna keep on shooting manual @Vinny

@everyone so im still asking for your guys step-step on manual shooting. anybody?

@everyone i still dont understand EF and EFS! like Goonies said, you cant use EFS on full-frame. And I've also read that EFS are EFS because theyre smaller, sooo i thought theyre smaller because they are actually smaller focal lengths that when you put into a 1.6x crop factor camera, they will actually show 18-55 instead of like 12-35 or something since youll never use it on a full frame?

Vinny · Oct 17, 2010

This is what I found: Canon EF-S lens mount - Wikipedia, the free encyclopedia

The focal length range (18-55mm) is based on 35mm camera standards. In the article it states that vignetting happens on a full frame or 35 mm camera.

As for steps... Stay at the lowest native ISO, shoot in RAW, find what you want to shoot, think about what it is you see, adust the aperture to get that look, look into the camera, adjust the shutter speed to get a "correct" exposure (however your camera does that), maybe adjust the aperture is shallow depth of field isn't wanted and take the photo. You may want to bracket up or down to adjust the exposure. If the exposure can't be adjusted due to too dark then adjust your ISO to accomodate the conditions.

peacock · Oct 17, 2010

In response to the above post, I absolutely agree that it's best to stay at the lowest native ISO (should be like 200), but then, it is essential that you increase ISO (or use auto ISO) to avoid blurry pictures for having too long shutter speeds (when hand-held). It's always better to have more noise than to have blurred pictures because of shake. With your camera, noise shouldn't be too much of a problem if you stay at a good range ;-).

Also, I apologize if I confused you there with the EF-S, because I'm a Nikon user

. I forgot that you can't use EF-S on EF or something like that.

"they will actually show 18-55 instead of like 12-35 or something since youll never use it on a full frame?"

You're right on what you're saying if you're comparing the image produced between a small-sensor and a full-frame-sensor. But the focal lengths still stay the same, the lens barrel does not enlarge when you put it on a small-frame camera body. (BTW, when I refer to small-frame sensor, I'm talking about the sensor that a EF-S camera uses)

If you're still confused, think of it this way. Imagine the sensor as a rectangular film. A full-frame sensor would be the bigger film and the smaller-frame sensor would be the smaller film. The bigger film is placed in a dark room. Now I would project an image onto it, so an image is created onto the film. If this time I use the smaller film, the image would appear cropped when compared to the bigger film. So when you bring both films to a photo booth to get prints of them, the smaller film would produce an image which would look "zoomed" (if they are printed on the same sized paper).

If you get that part, here's the second part. How did I project that image mentioned before? I was using a lens. It was a 50mm. It also happens to be an EF lens. Now I will try using an EF-S 50mm lens: the resulting image on both films should be EXACTLY the same as before. The ONLY difference is possible vignetting (black shades on the corners of your image) for the larger film and slight difference in image quality. Why? EF-S lens are designed for smaller frame sensors and NOT full-frame sensors. Since smaller-frame sensor would be the smaller film in our scenario, part of the image would be cropped. The cropped part is not needed and therefore is not important. So Canon can make a lens that is cheaper and more economical by making certain parts of the lens smaller (STILL 50mm). Hence producing what we call an EF-S lens. However, you could still use an EF lens on the smaller film/sensor. Because the image produced by the EF lens is bigger than the film/sensor so no vignetting to worry about. Just your cash spent. According to my knowledge, you can use your Canon with both EF and EF-S lens, since your camera uses the smaller sensor, both types would work fine.

Depending on what you're used to, some people like to calculate 35mm (full-frame) equivalent, since it's the "standard" size for films and sensors. Since your sensor is 1.6x smaller than 35mm, you would multiply the focal length of the lens by 1.6x to get the '35mm equivalent' (that is, if you usually work with pictures stated with the 35mm equivalent).
So if my 50mm lens is being used on your smaller-frame sensor, the resulting image on the sensor would look like it was taken with a 80mm lens (50x1.6=80), If it were used on a full-frame 35mm sensor. Another words, if you use a 80mm lens on a full-frame sensor, the resulting image would look the same as if taken with a 50mm lens on your small-frame sensor. Does that make sense?

I hope this really helps. :blushing:

doomhart · Oct 18, 2010

Ohhhh. Ok, I think I understand now! So on EFS lenses, the focal length printed in front of the lens is still the actual focal length even though the sensor has a 1.6x crop factor and EFS can only be used with them! So my EFS 18-55 at the widest, is still 18mm but the image i get to my card is looks cropped and similar to an image taken with a full-frame sensor using a 29mm lens?

Does this make sense? :razz:

KmH · Oct 18, 2010

Canon EF-S lenses are bigger around at the mount end of the lens than EF lenses and protrude further into the camera body mirror box on EF camera bodies.

EF-S lenses will mount on EF camera bodies, but the larger diameter mount end interfers with the movement of the camera body mirror.

Cburnett, the copyright holder of this work, hereby publishes it under the following license:

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

EF-S lens. Note the black rubber ring and how much further above the electrical contacts the rear of the lens is:

EF lens:

I, the copyright holder of this work, hereby publish it under the following licenses:

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".