50mm 1.8 some questions

[J.A.F. Doorhof]

I played a bit with this lens and in the studio envirement it was about as sharp as my 28-75 f2.8 Tamron which I think is amazing because that is one sharp lens.

I'm now thinking on buying one but I have a few real life questions.

When shooting in a dark surrounding I have understand that I can use 1.8 if the subject is further away than let's say 4-5 mtrs and get a usable DOF.

When I would have a shutterspeed of 1/10 on 2.8 how much would that be on 1.8 (sorry I don't have the whole fstop theorie not yet in my head).

Greetings,
Frank

[kawter2]

1/10th is to 2.8 as 1/30th is to 1.8




1/10-| 1/15-| 1/20-| 1/30
2.8---| 2.4---| 2.0---| 1.8

[J.A.F. Doorhof]

Thanks so much.

[MegaTron]

1/10th is to 2.8 as 1/30th is to 1.8




1/10-| 1/15-| 1/20-| 1/30
2.8---| 2.4---| 2.0---| 1.8

Sorry, newb question. Would someone mind telling me why I would have to know these numbers?

[tim]

Sorry, newb question. Would someone mind telling me why I would have to know these numbers?

You need to understand aperture and its relation to shutter speed and ISO to even begin to take advantage of an SLR camera. A local class is the best idea, it worked for me.

[MegaTron]

Any particular threads you guys could suggest, or any links that might explain this?

A cliffnotes version would be nice.

Planning on taking some classes at the JC when I have time. Any help would be appreciated. Thanks.

[Poco]

The smaller the f/stop number the larger the aperture (the size of the hole that the light goes through). The larger the hole the more light you get. The more light you get through the less time you need to keep the shutter open (faster shutter speed). The faster the shutter speed the less blur you get from camera shake or moving objects.

There is a mathematical relationship between them, and that is the basis of this question.

So the advantage of those lenses with with very low f/stop values like 1.4 or 1.8 or 2.0 is that they can let more light through to the sensor/film and therefore the shutter speed can be increased and you hopefully get a less blurry images when there isn't much light available.

There are a lot of books on this subject or a Google search will help.

[blue_max]

The smaller the f/stop number the larger the aperture (the size of the hole that the light goes through). The larger the hole the more light you get. The more light you get through the less time you need to keep the shutter open (faster shutter speed). The faster the shutter speed the less blur you get from camera shake or moving objects.

There is a mathematical relationship between them, and that is the basis of this question.

So the advantage of those lenses with with very low f/stop values like 1.4 or 1.8 or 2.0 is that they can let more light through to the sensor/film and therefore the shutter speed can be increased and you hopefully get a less blurry images when there isn't much light available.

There are a lot of books on this subject or a Google search will help.

Nicely and simply put. I have one question though, why don't they just make the aperture bigger to make a quicker lens? :confused: is it to do with focus?

Graham

[martook]

Nicely and simply put. I have one question though, why don't they just make the aperture bigger to make a quicker lens? :confused: is it to do with focus?

Graham

Because it's harder to do, much more expensive and damn heavy? :)

[jimchapin468]

It would be like carrying a 'sheep' around -- real heavy and no telling what that lens would cost.

[blue_max]

Because it's harder to do, much more expensive and damn heavy? :)

I am aware that the faster lenses are built with much more glass (I have the 135L prime). My question is why can't they make JUST the shutter open a bit wider.

Graham

[CyberDyneSystems]

.... ?

Hard to picture what your question means.. but a larger "shutter" would mean what? A larger Film plane/Cmos sensor?

It is only the lens that limits the amount of light that hits the sensor or film.. the shutter does not have any effect beynd it's being open or closed. When it is open it is WIDE open.. like f/0 open. It has no effect on the amount of light allowed to hit the sensor.

Consider the film/sensor as a large water basin..
The shutter is a full sized lid for that basin.

Your lens is a hose.. to fill the basin..
The larger the aperture.. (lower the f/stop) the larger the diameter of the hose.

the shutter when closed will not let ANY of the water that the hose provides into the basin.. but when open, it will allow as much into the basin as the hose can possibly provide.

The Shutter/lid can never be a bottleneck beyond it's being open or closed...
The bottle neck is allways the lens.

to get 5 gallons of water into your basin.. if you use a small f/6.3 hose.. you will need to leave the water running (open the lid/shutter) for a longer period of time than if you used a larger f/2.8 hose/shutter, as the 2.8 hose will let more water through quicker.

the Lid/shutter is the size of the basin.. not the size of any hoses...

[blue_max]

Hi CDS, I guess what you are saying is that when the aperture is wide open, it can't let any more light in. Stopping down just restricts the amount of light falling on the sensor. I just wondered why a wider aperture wouldn't let even more light in, but I get it now. You live and learn.

Graham

[Andy_T]

Frank,

to answer your question - this is an image I took with my 20D and 50/1.8 MKI.

f/2.0
ISO 3200
1/40 s handheld
Large JPG, noise reduction with Noiseware Community edition
resize & USM in BreezeBrowser

Now while I am not going to make 12x18 prints from it, it is definitely ok for the web. It loses quite a bit from conversion below 100K.

Best regards,
Andy

[ericgtr]

.... ?

Hard to picture what your question means.. but a larger "shutter" would mean what? A larger Film plane/Cmos sensor?

It is only the lens that limits the amount of light that hits the sensor or film.. the shutter does not have any effect beynd it's being open or closed. When it is open it is WIDE open.. like f/0 open. It has no effect on the amount of light allowed to hit the sensor.

Consider the film/sensor as a large water basin..
The shutter is a full sized lid for that basin.

Your lens is a hose.. to fill the basin..
The larger the aperture.. (lower the f/stop) the larger the diameter of the hose.

the shutter when closed will not let ANY of the water that the hose provides into the basin.. but when open, it will allow as much into the basin as the hose can possibly provide.

The Shutter/lid can never be a bottleneck beyond it's being open or closed...
The bottle neck is allways the lens.

to get 5 gallons of water into your basin.. if you use a small f/6.3 hose.. you will need to leave the water running (open the lid/shutter) for a longer period of time than if you used a larger f/2.8 hose/shutter, as the 2.8 hose will let more water through quicker.

the Lid/shutter is the size of the basin.. not the size of any hoses...
This is a great explanation and puts things I didn't understand into perspective for me, thanks for this!

[Andy_T]

Aperture in a nutshell ... it starts at f/1.0, and you can calculate each full stop by multiplying the previous stop with 1.4 (~square root of 2). Each full stop has exactly half the light of its predecessor.

1.0 - 1.4 - 2.0 - 2.8 - 4.0 - 5.6 - 8.0 - 11 - 16 - 22

Best regards,
Andy

[cmM]

Andy, your white balance is slightly off http://www.photography-on-the.net/forum/images/smilies/icon_wink.gif



.... ?

Hard to picture what your question means.. but a larger "shutter" would mean what? A larger Film plane/Cmos sensor?

It is only the lens that limits the amount of light that hits the sensor or film.. the shutter does not have any effect beynd it's being open or closed. When it is open it is WIDE open.. like f/0 open. It has no effect on the amount of light allowed to hit the sensor.

Consider the film/sensor as a large water basin..
The shutter is a full sized lid for that basin.

Your lens is a hose.. to fill the basin..
The larger the aperture.. (lower the f/stop) the larger the diameter of the hose.

the shutter when closed will not let ANY of the water that the hose provides into the basin.. but when open, it will allow as much into the basin as the hose can possibly provide.

The Shutter/lid can never be a bottleneck beyond it's being open or closed...
The bottle neck is allways the lens.

to get 5 gallons of water into your basin.. if you use a small f/6.3 hose.. you will need to leave the water running (open the lid/shutter) for a longer period of time than if you used a larger f/2.8 hose/shutter, as the 2.8 hose will let more water through quicker.

the Lid/shutter is the size of the basin.. not the size of any hoses...

He speaks in riddles http://www.photography-on-the.net/forum/images/smilies/icon_razz.gifhttp://www.photography-on-the.net/forum/images/smilies/icon_wink.gif
Well put CDS

[J.A.F. Doorhof]

I will order the lens I think

[cmM]

frank, that little lens is capable of outstanding results. I've taken some of my best pictures with it.

[J.A.F. Doorhof]

I will see, I just ordered it.
I still have some trouble with the lens when to use because in the studio I could not really see a difference in sharpness compared with my Tamron 28-75 f2.8 but outside I can use it for some cool effects with the background I guess and in some darker areas

[guitarman]

When I first got this lens I liked it. But learning more and playing with better lenses, I wished that I had got the 50 mm 1.4. The focusing on the 1.8 is terrible and the bokeh is not all that good of a look. The bokeh I get from my 17-40mm F4L is so much smoother looking. At first I just bought it cause it seemed like such a give away and it does take nice pictures when it finally focuses. The sharp pictures that you get are definitely worth the price of the lens. It takes a little work to get the shots. I thought that I would end up going with all zooms and it wouldn't matter. But now I've made up my mind to invest in some primes before I think of zooms because I like the sharpness and quality more than the convenience.

[RAitch]

Like you said before, at 1.8... keep your subject at least 4 feet from you and you should be fine. Get too close and even on MF you'll get some weird results.

If you have enough light to get above 2.8 (on your way to f/8) set it there. The lens seems to get a bit sharper the farther away from 1.8 you get. At 2.8 or 3.2 or so... you can get some nice results even up close (around 2.5 feet away).

[Andy_T]

Frank ...

Actually, my 50/1.8 was about a stop sharper than my Tamron 28-75/2.8.
But ... I received my 50/1.4 last week and I can tell you that it is the most incredible lens ... I am truly in love :)
I liked the 50/1.8 quite a lot, but I love the 50/1.4.

My Tamron 28-75/2.8 hasn't been on my camera since... and I am currently thinking about getting the 85/1.8 and the EF 28/1.8 or the new Sigma 30/1.4 to replace it completely.

Andy, your white balance is slightly off http://www.photography-on-the.net/forum/images/smilies/icon_wink.gif


That might well be the case ... haven't really paid much attention to white balance yet - always used AWB :o

But the shot was taken in a pub brewery with very warm reddish light. Behind the subject was the big gleaming copper brewingstill that might also have added a bit of warmth to the image.

Best regards,
Andy

[blue_max]

Frank ...

Actually, my 50/1.8 was about a stop sharper than my Tamron 28-75/2.8.
But ... I received my 50/1.4 last week and I can tell you that it is the most incredible lens ... I am truly in love :)
I liked the 50/1.8 quite a lot, but I love the 50/1.4.

My Tamron 28-75/2.8 hasn't been on my camera since... and I am currently thinking about getting the 85/1.8 and the EF 28/1.8 or the new Sigma 30/1.4 to replace it completely.

Best regards,
Andy

Having a fast lens is like having an extra string on a guitar. You don't have to use it, but it allows you go to places that you haven't been. There is really no substitute. Primes are a very different style of photography. You have to give it a try and the 50mm 1.8 is a great lens to dabble.

Graham

[guitarman]

Having a fast lens is like having an extra string on a guitar. You don't have to use it, but it allows you go to places that you haven't been. There is really no substitute. Primes are a very different style of photography. You have to give it a try and the 50mm 1.8 is a great lens to dabble.

Graham

Absolutely. I guess thats the most benefit of me buying the 50mm 1.8. It showed me the possibilities with primes and I found that I lean towards that style.
Not much use for the seven stringed guitar though.

[scr7b]

Aperture in a nutshell ... it starts at f/1.0, and you can calculate each full stop by multiplying the previous stop with 1.4 (~square root of 2). Each full stop has exactly half the light of its predecessor.

1.0 - 1.4 - 2.0 - 2.8 - 4.0 - 5.6 - 8.0 - 11 - 16 - 22

Best regards,
Andy

Hi Andy... whenever someone puts something in a nutshell, there's always someone else to come along and point out an error... Sorry, that's me this time! http://www.photography-on-the.net/forum/images/smilies/icon_smile.gif

Aperture doesn't necessarily start at f/1.0, according to my EF Lens Work III book, in 1961 Canon introduced a 50mm f/0.95 lens.

The "f number" is just the relationship between focal length and aperture diameter, so a 50mm f/0.95 lens has an aperture which is bigger than 50mm. (52.6mm)

The 50mm f/1.4 has an aperture of 35.7mm, and so on...

This has been an interesting thread!

[Andy_T]

Hahahaha ... should have said 'full stops start at f/1.0' :D

After all, f/0.95 can hardly be called a 'full' stop.

http://www.photo.net/comments/attachment/13480493/95c.jpg

Best regards,
Andy

[blue_max]

Absolutely. I guess thats the most benefit of me buying the 50mm 1.8. It showed me the possibilities with primes and I found that I lean towards that style.
Not much use for the seven stringed guitar though.

Good for you. The 1.4 is a great lens - and reasonably priced in the range. You're right about the 7 stringed guitar, I obviously mean the 13 string version. I must have been thinking about string to your bow or something like that. Sell your 1.8 and get your money back on Ebay or something.

Graham

[guitarman]

Good for you. The 1.4 is a great lens - and reasonably priced in the range. You're right about the 7 stringed guitar, I obviously mean the 13 string version. I must have been thinking about string to your bow or something like that. Sell your 1.8 and get your money back on Ebay or something.

Graham

The place that I bought from gaurantees me up to half back on any lenses, cameras that I want to trade in for upgrade. Would I do so much better on ebay as to warrant going through the extra hassle of trying to sell? I'm thinking not as the lens is priced pretty low in the first place.

[blue_max]

The place that I bought from gaurantees me up to half back on any lenses, cameras that I want to trade in for upgrade. Would I do so much better on ebay as to warrant going through the extra hassle of trying to sell? I'm thinking not as the lens is priced pretty low in the first place.

Post it on here for two thirds and you will be doing everybody a favour.

Graham

[J.A.F. Doorhof]

Allright allright changed my order to a 1.4 :D

[Andy_T]

Bravo ... you will not regret it :D

Best regards,
Andy

[ericgtr]

Allright allright changed my order to a 1.4 :D
Just got mine yesterday and am very happy with it, good choice!

[Andy_T]

My Tamron 28-75/2.8 hasn't been on my camera since... and I am currently thinking about getting the 85/1.8 and the EF 28/1.8 or the new Sigma 30/1.4 to replace it completely.

:o

Don't know how it could happen ... but I was just looking at an eBay auction for a mint EF 28/1.8 with EW-63 and filter and must have accidentally hit the 'submit bid' button :o:o:o

Well ... never mind. $275 doesn't sound too bad for that lens :wink:

:lol:


Best regards,
Andy

[RAitch]

There are a lot of bands that use 7 string guitars... however, most of them end up bent over playing them off the ground and banging their heads into the ground... but they use that 7th string almost all the time.

I guess that's true with some people too. If they're JUST buying the lens for the extra stop... they'll probably only use those extra stops (like the 7th chugga-chugga string).

[DocFrankenstein]

Aperture doesn't necessarily start at f/1.0, according to my EF Lens Work III book, in 1961 Canon introduced a 50mm f/0.95 lens.
Well... it doesn't start anywhere really. You could engineer a f/0.5 lens, it's just people don't need it.

[grego]

Hahahaha ... should have said 'full stops start at f/1.0' :D

After all, f/0.95 can hardly be called a 'full' stop.

http://www.photo.net/comments/attachment/13480493/95c.jpg

Best regards,
Andy

Round up. ;)

[guitarman]

There are a lot of bands that use 7 string guitars... however, most of them end up bent over playing them off the ground and banging their heads into the ground... but they use that 7th string almost all the time.

I guess that's true with some people too. If they're JUST buying the lens for the extra stop... they'll probably only use those extra stops (like the 7th chugga-chugga string).

Steve Vai is the most notable 7 string player and he plays it well.

[JulianL]

Allright allright changed my order to a 1.4 :D

I just picked up a 50mm f/1.4, you will not be disappointed. It's a great lens.

[Mikezoom]

Just bought a 1.8 NEW for $145, can't wait to try it out.

Mikezoom. :)

[J.A.F. Doorhof]

Isn't that a bit steep for the 1.8 ?
It's offered here for arround 70 euro's ?

[Mikezoom]

$145.00 Australian Dollars! :)

Mikezoom.

[Jon]

Well... it doesn't start anywhere really. You could engineer a f/0.5 lens, it's just people don't need it.

Say rather, people don't need it enough to pay the 5-digit (US) price. I'm sure paparazzi and serious photojournalists alike could use f/0.5 if it was available in an appropriate focal length. But it'd probably cost more than the 1200 L.