what is this 'f ' rating???

stupot · 24-08-2005, 21:15

hello all

yes another newbie here!!

recently got the photography bug. i am about to take the leap into digital SLR and purchase a canon 350d.

trying to decide on what lens or lenses to get!! but am stumped on what the f rating means i.e f2.8 after lens descriptions..

Something to do with aperture perhaps??

Can anyone explain

Also any suggestions on lenses greatly appreciated, sorry for another 'what lens' post...

fingerz · 24-08-2005, 21:42

Hi stupot.

I'm another relative newbie. The f number is the maximum aperture. The smaller the number, the wider the aperture, so f/1.8 is very wide and will let in lots of light. And f/22 is very small and will only let in a small amount of light.

The trade-off is that wide apertures allow fast shutter speeds but only have shallow depth of field (the area of the pic that is in focus). Whereas small apertures need slower shutter speeds (so tripods are handy) but have a much larger depth of field.

As for lenses, the Canon 50mm f/1.8 is a good lens for low light and other general stuff and it's cheap (around £60). The Sigma 70-300 is a great long zoom and won't break the bank either (£114 delivered from www.onestop-digital.co.uk I think).

DaveG · 24-08-2005, 22:12

What lens would suit depends on what type of photo's you want to take. Do you have any particular interest? ie..portraits/landscapes/wildlife?

***Steve*** · 24-08-2005, 22:26

Quote:

Originally Posted by DaveG

What lens would suit depends on what type of photo's you want to take. Do you have any particular interest? ie..portraits/landscapes/wildlife?

Thats the big question, what subject do you want to photograph, closely followed by how much can your afford/want to spend on the lens?

Gandhi · 24-08-2005, 23:15

Generally though, the faster the lens (the lower the f number) the higher quality the lens is. I think this is especially pertinent with zoom lenses. It's to do with the ability of the lens elements to transmit light, which then translates into image quality. There are other factors that affect it, but a f1.8 50mm lens will be of better quality than an f4 50mm lens.

stupot · 24-08-2005, 23:45

many areas interest me, mainly my photos up to now are of landscapes and close ups so I'd be looking at a lens or more likely lenses that can offer me the ability to take pictures in these areas. As for what i can afford well its more like what my plastic can take...

I suppose I would pay between 200 - 400 for a lens maybe a little more. the maximum is about £1500 for camera (350d) and 2-3 lenses. so i think i could get a pretty good kit for that but no idea where to start!!

Now i've been told by a friend and read a recent review to avoid the lenses that come bundled with the camera as there generally substandard. I also think that if i'm going to spend that amount of dosh it needs to be a good kit..

Any suggestions

DaveG · 25-08-2005, 00:04

canon EF 17-40 L is a great lens, but comes in at around £550.

The 17-85 is more reasonable and will offer you a bigger range but I haven't seen a review for this.

stupot · 25-08-2005, 00:06

cheers dave will have a look

CT · 25-08-2005, 00:44

My first lens which I bought with the camera was the 17-85 EF-S which offers a really useful range for general 'walkabout' photography, and the image stabilisation is a tremendous advantage. I wouldn't hesitate to recommend it - it's a fantastic crisp lens, not quite up to L glass standard, but it's close.

***Steve*** · 25-08-2005, 09:41

Lets cover this in a little detail..

The kit lens I presume that you are talking about will be the 18-55 mm that the majority of people already had just to get them started. It’s available bundled with the 300D/350D/20D and as such many, many people now own a copy of this lens.

As a beginners lens it is excellent, it covers a range that I would assume you would be shooting at with your interest in landscape and to replace that lens with something that has a similar range but better quality will cost you a lot more..probably as much as £600. I have seen some excellent results from the 18-55 but I have also seen some shocking ones as well. The key to this is make sure you get a good example of this lens and also make sure that you learn your equipment to get the best from it.

I wouldn’t discount getting the kit lens just to start you off.

The next choice I would recommend is the Tamron 17-35 F2.8 XR DI IF, lots of letters there but underneath it all it’s a cracking wide angle lens that’s both sharp, fast, small and light. The results that are possible from this lens are far beyond its cost would suggest. It can be bought in the UK for around £360 last time I checked.

The next step up will have to be the Canon 17-40L, this widely accepted to be a very high quality lens and many people are fortunate enough to own one. The quality of this lens is unquestionable but as it comes from Canon’s premium/pro range it carries the price tag to match, if you shop around and are lucky you may be able to find a new one for around £550. Secondhand examples are rare. The build quality is excellent and it’s a weather sealed lens as well, when used on the pro range of Canon cameras it allows both to be weather resistant.

The next stage would be the 17-85IS that CT has covered above, it has a longer range than the two I have mentioned so far, has Image stabilization but is not as sharp as the 17-40L and the cost will be similar. You will have to weight up the benefits and pitfalls of that lens compared to the others and how it fits into your idea of what you will use.

The last lens I would like to mention (for now) is the brand new Canon EF24-105f4 L USM IS, this is not available just yet and was only announced this week. The benefit of this lens is that it has a wider range and probably most useful to you than all the others mentioned here, it has IS and benefits from being an L lens as well. Basically it’s the best that Canon can do at this time, it has all their latest technology, has the best optics that Canon can make and will undoubtedly be made well as a lens. There are no examples of pictures that have been taken with this lens yet as its so new, in fact people are still guessing at the price, but it will be worth keeping an eye open for reviews and once the price has been set you will be able to judge if it should stay on your short list or not.

There is a lot of information there to swallow, if you have any more questions just shout.

ppuga · 25-08-2005, 16:58

I recommend you to try the camera with the kit lens it has, and go on from there, shot a lot of photos, and then when you have used it some time, see what you really need in a lens. Then, I think you could know better what to look for.

stupot · 25-08-2005, 17:53

cheers guys will check out your recomendations, i think i'm probably going to take your advice about the 18 - 55mm lens that comes bundled and get it as a starting point, the bundle price is only an extra £60. so for that price silly not to.

24-08-2005, 21:15	#1 (permalink)
stupot Forum Regular Join Date: Aug 2005 Location: Corfe Mullen, Wimborne, Dorset Posts: 1,319	what is this 'f ' rating??? hello all yes another newbie here!! recently got the photography bug. i am about to take the leap into digital SLR and purchase a canon 350d. trying to decide on what lens or lenses to get!! but am stumped on what the f rating means i.e f2.8 after lens descriptions.. Something to do with aperture perhaps?? Can anyone explain Also any suggestions on lenses greatly appreciated, sorry for another 'what lens' post...

25-08-2005, 00:04	#7 (permalink)
DaveG Been here a while Join Date: Apr 2005 Location: Kent Posts: 262	canon EF 17-40 L is a great lens, but comes in at around £550. The 17-85 is more reasonable and will offer you a bigger range but I haven't seen a review for this. Last edited by DaveG : 25-08-2005 at 00:06.

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24-08-2005, 21:42	#2 (permalink)
fingerz Forum Regular Join Date: Jul 2005 Posts: 790	Hi stupot. I'm another relative newbie. The f number is the maximum aperture. The smaller the number, the wider the aperture, so f/1.8 is very wide and will let in lots of light. And f/22 is very small and will only let in a small amount of light. The trade-off is that wide apertures allow fast shutter speeds but only have shallow depth of field (the area of the pic that is in focus). Whereas small apertures need slower shutter speeds (so tripods are handy) but have a much larger depth of field. As for lenses, the Canon 50mm f/1.8 is a good lens for low light and other general stuff and it's cheap (around £60). The Sigma 70-300 is a great long zoom and won't break the bank either (£114 delivered from www.onestop-digital.co.uk I think).

24-08-2005, 22:12	#3 (permalink)
DaveG Been here a while Join Date: Apr 2005 Location: Kent Posts: 262	What lens would suit depends on what type of photo's you want to take. Do you have any particular interest? ie..portraits/landscapes/wildlife?

24-08-2005, 23:15	#5 (permalink)
Gandhi Forum Regular Join Date: Jul 2005 Location: bath, somerserset Posts: 966	Generally though, the faster the lens (the lower the f number) the higher quality the lens is. I think this is especially pertinent with zoom lenses. It's to do with the ability of the lens elements to transmit light, which then translates into image quality. There are other factors that affect it, but a f1.8 50mm lens will be of better quality than an f4 50mm lens.

24-08-2005, 23:45	#6 (permalink)
stupot Forum Regular Join Date: Aug 2005 Location: Corfe Mullen, Wimborne, Dorset Posts: 1,319	many areas interest me, mainly my photos up to now are of landscapes and close ups so I'd be looking at a lens or more likely lenses that can offer me the ability to take pictures in these areas. As for what i can afford well its more like what my plastic can take... I suppose I would pay between 200 - 400 for a lens maybe a little more. the maximum is about £1500 for camera (350d) and 2-3 lenses. so i think i could get a pretty good kit for that but no idea where to start!! Now i've been told by a friend and read a recent review to avoid the lenses that come bundled with the camera as there generally substandard. I also think that if i'm going to spend that amount of dosh it needs to be a good kit.. Any suggestions

25-08-2005, 00:06	#8 (permalink)
stupot Forum Regular Join Date: Aug 2005 Location: Corfe Mullen, Wimborne, Dorset Posts: 1,319	cheers dave will have a look

25-08-2005, 00:44	#9 (permalink)
CT Feet under the table Join Date: Mar 2005 Location: West Mids UK Posts: 3,500	My first lens which I bought with the camera was the 17-85 EF-S which offers a really useful range for general 'walkabout' photography, and the image stabilisation is a tremendous advantage. I wouldn't hesitate to recommend it - it's a fantastic crisp lens, not quite up to L glass standard, but it's close.

25-08-2005, 09:41	#10 (permalink)
*Steve* Pixalo Crew Join Date: Jan 2005 Location: An Englishman living in Germany Posts: 16,158	Lets cover this in a little detail.. The kit lens I presume that you are talking about will be the 18-55 mm that the majority of people already had just to get them started. It’s available bundled with the 300D/350D/20D and as such many, many people now own a copy of this lens. As a beginners lens it is excellent, it covers a range that I would assume you would be shooting at with your interest in landscape and to replace that lens with something that has a similar range but better quality will cost you a lot more..probably as much as £600. I have seen some excellent results from the 18-55 but I have also seen some shocking ones as well. The key to this is make sure you get a good example of this lens and also make sure that you learn your equipment to get the best from it. I wouldn’t discount getting the kit lens just to start you off. The next choice I would recommend is the Tamron 17-35 F2.8 XR DI IF, lots of letters there but underneath it all it’s a cracking wide angle lens that’s both sharp, fast, small and light. The results that are possible from this lens are far beyond its cost would suggest. It can be bought in the UK for around £360 last time I checked. The next step up will have to be the Canon 17-40L, this widely accepted to be a very high quality lens and many people are fortunate enough to own one. The quality of this lens is unquestionable but as it comes from Canon’s premium/pro range it carries the price tag to match, if you shop around and are lucky you may be able to find a new one for around £550. Secondhand examples are rare. The build quality is excellent and it’s a weather sealed lens as well, when used on the pro range of Canon cameras it allows both to be weather resistant. The next stage would be the 17-85IS that CT has covered above, it has a longer range than the two I have mentioned so far, has Image stabilization but is not as sharp as the 17-40L and the cost will be similar. You will have to weight up the benefits and pitfalls of that lens compared to the others and how it fits into your idea of what you will use. The last lens I would like to mention (for now) is the brand new Canon EF24-105f4 L USM IS, this is not available just yet and was only announced this week. The benefit of this lens is that it has a wider range and probably most useful to you than all the others mentioned here, it has IS and benefits from being an L lens as well. Basically it’s the best that Canon can do at this time, it has all their latest technology, has the best optics that Canon can make and will undoubtedly be made well as a lens. There are no examples of pictures that have been taken with this lens yet as its so new, in fact people are still guessing at the price, but it will be worth keeping an eye open for reviews and once the price has been set you will be able to judge if it should stay on your short list or not. There is a lot of information there to swallow, if you have any more questions just shout.

25-08-2005, 16:58	#11 (permalink)
ppuga Been here a while Join Date: Mar 2005 Location: México City, México. Posts: 290	I recommend you to try the camera with the kit lens it has, and go on from there, shot a lot of photos, and then when you have used it some time, see what you really need in a lens. Then, I think you could know better what to look for.

25-08-2005, 17:53	#12 (permalink)
stupot Forum Regular Join Date: Aug 2005 Location: Corfe Mullen, Wimborne, Dorset Posts: 1,319	cheers guys will check out your recomendations, i think i'm probably going to take your advice about the 18 - 55mm lens that comes bundled and get it as a starting point, the bundle price is only an extra £60. so for that price silly not to.