Whats with fast lenses????

[Escapism]

Why do people rate fast lenses? Is it actually for their low light ability or their sharpness?? Take for example the Nikon 50mm...everyone drools over the 1.4 but what does it REALISTICALLY do that the 1.8 cant? And further to this point...at 1.4, the DOF is so shallow that its just about useless (which is also the case at 1..

Post some pics that illustrate why huge $$ fast lenses are soooo drool worthy to the "average" photographer.

Gimme some feedback....

[wendellt]

the 1.4 is shallow if your close yto the subject but the further away you get the more depth of field you get with the f1.4

i could be wrong about this though

i'd say a 300mm f2 is ther fastest focussing lens

[darb]

Hi escapism,

I have exactly the same thoughts.

I am currently trialling a Nikkor 50mm F1.8 lens .. great lens and very sharp. But, in terms of its fast and wide aperture, Im finding that anythign less than about F3.5 / F4, the DOF is almost always a little too shallow to be of any use, therefore the expense of this wider aperture doesnt seem worthwhile, as im finding myself having to choose a tighter aperture, and then bump up ISO to keep my shutter fast. (motorsport under lights, for example.) At F1.8, or F1.4, the DOF is ridiculously shallow and almost useless.

Am i missing something? This leads me to think if i have to keep going to a tighter aperture, then I might aswell not have such a fast lens to start with ... EXCEPT for teh sharpness (which is kinda irrelevant to the discussion on DOF vs speed)

Perhaps its that a F1.8 lens is awful sharp at F4'ish ... where as a cheaper lens at F4 is quite soft?

I guess a lens such as a F2.8 300mm (or even a 80-200VR F2. ... would have a deeper DOF at F2.8 than a 50mm, so in those "sports" lens varietys, the extra speed IS useable?

[radar]

Hi,

Have a look at some discussions in a past thread.

http://www.dslrusers.net/viewtopic.php?t=7575

In there, you wil find a link to a site that does a side by side comparaison of the 1.8 and 1.4. It's in French, but pictures translate easily

HTH,

radar

[Greg B]

The difference between the 1.4 and the 1.8 is about 2/3 stop. Not much.

The other difference is in the quality of the construction - the 1.4 is typically made in Japan, the 1.8 in Thailand or China probably. The 1.4 is a much better constructed lens, however, I have the 1.8 and it is fantastic. I couldn't see the justification in spending more than twice as much on the 1.4, but some people think otherwise.

Personally, I think the 1.8 at <$200 is the best value lens in the Nikkor stable.

DoF is a consequence of aperture and camera/subject distance. Even wide open, you can get reasonable DoF - from 3 metres away, your DoF is going to be 25cm or so, quite enough to get a person's face in focus.

[darb]

those french tests make the F1.8 look like crap !!! compared to teh F1.4

it almost looks out of focus in teh F1.8 pics, i wonder if thats fiddled or what.

[darb]

hmm, the F1.8 50mm nikkor im borrowing is made i japan, not a "D" series lens ... and seems sharp as

were there different releases of this lens?

[MCWB]

Here's an example of why you might want a fast lens (click for larger image).


Nico Rosberg in (very) overcast conditions at the Belgian GP this year. Shot at 180 mm, 1/800, f/2.8, ISO200 with the 70-200 VR.

Let's compare it to what would happen to the same image shot with a 70-300 G. Not sure what the max aperture of the 70-300 G is at 180 mm, but let's say it's f/5.6. You're giving away 2 whole stops, which means to be shooting at the same shutter speed, you'd have to be at ISO800. Then consider that the 70-200 VR is much sharper wide open (f/2.8 ) than the 70-300 G is wide open (f/5.6). In order to increase sharpness you'd probably want to stop down at one stop with both lenses. This takes the 70-200 VR to f/4 and ISO400 (very useable), and the 70-300 G to f/8 and ISO1600 (yuck!). At this point the 70-200 VR will be sharp as, whereas the 70-300 G will still be soft.

As darb rightly points out, DOF is less of an issue with a long lens such as this.

Another comparison, I have both the 24-120 VR (f/3.5-5.6) and 17-55 DX (f/2.8 ). The 24-120 VR is sharpest at f/11. If you're shooting indoors in low light with flash and low ISO f/11 is crazy; f/5.6 is more where it's at. For the 24-120 VR, this is wide open at the telephoto end and one and a bit stops down at the wide end, and the image is noticeably softer. f/5.6 is a full 2 stops down from max aperture for the 17-55 DX, which is already pretty sharp wide open, and is even better at f/5.6.

On the other hand, one's bank balance is significantly poorer with the faster lenses.

So in answer to your question, it's both useability in low light and better sharpness at wider apertures.

[Glen]

Darb, the AF 50/1.8 (non D) came out from 1986 -2002, your version could be anywhere in there

One big point is most Auto focussing is done with the lens wide open (that is why there is a DOF preview button) so AF is available in low light when it might not otherwise be

[Escapism]

Darb, the AF 50/1.8 (non D) came out from 1986 -2002, your version could be anywhere in there

One big point is most Auto focussing is done with the lens wide open (that is why there is a DOF preview button) so AF is available in low light when it might not otherwise be

Good point Glen!

Darb, that lense is like 15 years old!!!!

[darb]

Great reply, i guess its not always how fast the lens is, or how sharp at its extreme end, but more the sharpness quality that is generally entwined WITH a fast lens a stop or two in.

ie, sure you might need to bump a stop or two to get a deeper DOF (that botht he cheap ANd expensive lens can both do), but it will be tack sharp, whereas the cheaper lens will still be too soft and youd have to tighten aperture a few more. (then lose too much shutter speed and have to sacrifice with ISO)

off topic, but I recall trialling my boss's Tokina 200 or 300mm F2.8 lens ... massive, ugly, heavy thing ... dont know why, it was a piece of junk. At F2.8 it was SO soft, that i had to go to about F6 before it got any sharpness ... and then my lightweight tamron cheapie was outperforming it. he did refer to it as a doorstop though.

Nikkor 300mm F2.8 (im yet to play) , different matter altogether im told!

As for the 50mm F1.8, as i said, ive found no use for such a shallow DOF at F1.8 as yet, so sitting around F4 ... but as others have said, its damn sharp, and a cheapie lens at F4 defiantely wouldnt be.

[Glen]

Darb, good point, many lenses seem to be at their best stopped down one or two stops. That means the 1.8 is sharp at F4 and a F4 lens might be at its best at F8, a big difference.

[darb]

umm, is anyone seeing the words in my first paragraph above as "...or how sharp it is at its BORING end" ?

WTF!! i didnt write "boring" and if i hit edit on that post, it shows "E*X*T*R*E*M*E" end, which is what i meant to write. (i used asterixes because whenever i wrote it , somethign on the forum changes it to "boring")

heres a screenshot of what it looks like in edit mode ;

[MCWB]

Haha, you've encountered the word filter!

[darb]

Haha, you've encountered the word filter!

what the?

why on earth does the forum replace the word "e*xtreme" with "boring" ?

[MCWB]

You've got to understand... Dad likes fucking with people's minds.

http://dslrusers.net/viewtopic.php?p=134092

[Escapism]

Exstream
X-tream
Ext-ream
Xtreme

[darb]

You've got to understand... Dad likes fucking with people's minds.

http://dslrusers.net/viewtopic.php?p=134092

okkk! it takes all sorts! (to make the world go round), just a little pedantic & self indulgent perhaps? (some would say anal, levity intact) Oh well, ill be sure to remember not to use that word, even though appropriate.

Given im ignorant to the terms of the local theocracy, I'm glad I proof read my post before, that word filter did so without telling me about it. I'm sure it'll keep garys enemy, the exxtreeeeme snowboarder at bay. (actually it took me a few minutes of "wtf" to figure that my eyes werent decieving me, jokes on me )

[Escapism]

Fuck me! Fucken censorship...beats the shit out of me as to why the fuck we censor some words and not others.

[Escapism]

Fuck me! Fucken fun...beats the shit out of me as to why the fuck we censor some words and not others.

Hey! I found the other word......censorship, censorship, censorship

[gstark]

self indulgent perhaps?

Oh yes, absobloodylutely!

And why not, pray tell?

We all have our little foibles,a nd messing with the minds of others, in very subtle ways, is one of my specialities.

Now that you're in on the joke, tell me what you call that quaint Japanese pasttime of getting drunk, and then trying to sing - usually nowehere near the key nor melody - with the music being made by som e god-awful machine playing an even worse midi rendition of the piece.

(some would say anal, levity intact)

Evil will suffice.

(actually it took me a few minutes of "wtf" to figure that my eyes werent decieving me, jokes on me )

Which is exactly the desired effect.

Thanx for playing; next please.

[Alpha_7]

For my thesis I had to do build a "mate in public" on Demand System, I was laughed at by my Peers. LOL -> Gary!!! Priceless!

[gstark]

Fuck me! Fucken fun...beats the shit out of me as to why the fuck we censor some words and not others.

It's something that I apply entrirely at my own discretion. The list - in the context that it's used here - is not intended to censor anyone, and it doesn't. As you can see, some words that you might it expect to change are not, but others, that refer to things that particularly piss me off, are.

So, think of it as a means of preserving my own sanity, what little of it I have left. There are some things in life that we simply shouldn't have to put up with, and this is one area where I do have some control over that.

If you appreciate my humour, great. if not, tough; get over it, 'cos I'm too old, ugly and cranky and I'm certainly not going to change.

[gstark]

Craig,

For my thesis I had to do build a "mate in public" on Demand System, I was laughed at by my Peers. LOL -> Gary!!! Priceless!

It's almost worth the pain, isn't it?

Oh yes, the other thing is that, when I first did this earlier in the year, I changed the output word after a few days. So we had one lot of messages coming through one way and then being quoted after translation, and a second lot being quoted a different way, with a third lot being subject to both sets of changes.

It wasn't simply fun to watch, but watching the reactions was almost as much fun as watcing everyone deal with the changes we implemented on April 1 this year.

[Alpha_7]

The sad thing is, I think my thesis could of been 100% better if it was based on Sex on Demand, rather then Drunk Dudes Singing poorly to dodgey soundtracks.

Practical testing and experimentation would of been interesting to document

[gstark]

Practical testing and experimentation would of been interesting to document

Bets, anyone?

[darb]

The world is your oyster, Gary.

[Oneputt]

Gary - old, ugly and cranky Are we twins

[christiand]

a provocation:

care factor ? ....

[gstark]

Gary - old, ugly and cranky Are we twins

You really don't want to go there

[Escapism]

Fuck me! Fucken fun...beats the shit out of me as to why the fuck we censor some words and not others.

It's something that I apply entrirely at my own discretion. The list - in the context that it's used here - is not intended to censor anyone, and it doesn't. As you can see, some words that you might it expect to change are not, but others, that refer to things that particularly piss me off, are.

So, think of it as a means of preserving my own sanity, what little of it I have left. There are some things in life that we simply shouldn't have to put up with, and this is one area where I do have some control over that.

If you appreciate my humour, great. if not, tough; get over it, 'cos I'm too old, ugly and cranky and I'm certainly not going to change.

I kneel before thee oh great King Gaz...please permit me to stay in the land of Starkalia. I promise to abide by all your forms of sensorship and will avoid the use of ex-tream language.

[gstark]

I kneel before thee oh great King Gaz...please permit me to stay in the land of Starkalia. I promise to abide by all your forms of sensorship and will avoid the use of ex-tream language.

Hey.

There's about ten words there, and most of those are variations of others in tehre. Get over it!

[Escapism]

I kneel before thee oh great King Gaz...please permit me to stay in the land of Starkalia. I promise to abide by all your forms of sensorship and will avoid the use of ex-tream language.

Hey.

There's about ten words there, and most of those are variations of others in tehre. Get over it!

Granted a pardon? Oh the unbridled joy, in return my first born shall be yours!

[johnd]

Oh dear. Here we go again.

[sirhc55]

That’s it - lenses at 10 paces, Nikkor’s only allowed

[johnd]

Of topic, but this whole thread is:

Chris have you used the Sigma 150mm 2.8 macro? I'm thinking of getting it and an SB800 to give macro a serious go.

[sirhc55]

Of topic, but this whole thread is:

Chris have you used the Sigma 150mm 2.8 macro? I'm thinking of getting it and an SB800 to give macro a serious go.

John - I have had the Sigma for around one year and use it with the SB800 on a regular basis - this POTW was taken with this combination

http://www.dslrusers.net/viewtopic.php?t=11170&postdays=0&postorder=asc&highlight=potw&start=0

[gstark]

I kneel before thee oh great King Gaz...please permit me to stay in the land of Starkalia. I promise to abide by all your forms of sensorship and will avoid the use of ex-tream language.

Hey.

There's about ten words there, and most of those are variations of others in tehre. Get over it!

Granted a pardon? Oh the unbridled joy, in return my first born shall be yours!

My point was that this line of discussion is off topic. Please now return to on-topic posts only, and thank you for your cooperation.

[stubbsy]

Oh dear. Here we go again.

Yep. I actually find the whole word censor thing kinda funny and I've had mate in public and extreme in my posts so I know what I'm talking about. Never had the Pink Floyd/Mr Squiggle one though. I must confess, however, to having an odd sense of humour.

Escapism, please don't take it personally - Gary picks on all of us equally.

Edit: And back on topic - the big thing about fast glass is that they tend to be made to a very high quality. They'll be optically purer, more mechanically sound and, generally, deliver nicer looking result across their range. eg the 70-200 2.8 VR isn't just fast it has the most delightful boke regardless of the focal length. It is also internal focusing which reduces the chance of dust in the mecahnism. So you're not just paying for speed you are also paying for quality

[Nnnnsic]

Gary picks on all of us equally.

No one more so than I.

[MCWB]

Edit: And back on topic

On topic is the new off topic apparently!

[darb]

I kneel before thee oh great King Gaz...please permit me to stay in the land of Starkalia. I promise to abide by all your forms of sensorship and will avoid the use of ex-tream language.

Hey.

There's about ten words there, and most of those are variations of others in tehre. Get over it!

Granted a pardon? Oh the unbridled joy, in return my first born shall be yours!

My point was that this line of discussion is off topic. Please now return to on-topic posts only, and thank you for your cooperation.

hahaah 'damn, now youre using my medicine, i now revert & order you to cease talking! Only IM allowed to be sarcastic, cheeky and annoying coz this is MY sandpit"

"thankyou for your cooperation"

[darb]

Well i took the 50mm F1.8 to a night event at a Motorplex ... and boy was the lens helpful ... will post some pics soon, i particularly like people shots in low light with this lens, because it allows for some very nice and interesting colour. Was handy from a motorsport perspective, flash filled pics usually look bland, not to mention waiting on recycvle times and just as limited in range as a 50mm is anyway (burnouts / stationary mostly and i was allowed in pits)

I also found that at infinity, F1.8 , still pretty sharp ... so the shallow DOF doesnt seem to be a problem on a far subject.

it was funny seeing a guy there with d70s, a SB600 ... and was trying to FLASH FILL THE STADIUM ! ... i had a quick chat, looked at the pics, dull and way underexposed ... and sitting in Program mode. Felt like strangling him and pinching the sb600 seeing as i dont have one.

[Mj]

Gary picks on all of us equally.

No one more so than I.

As it should be !!!

[darb]

heres the pics from aforementioned posts ;

http://www.dslrusers.net/viewtopic.php?t=11758

[KerryPierce]

Why do people rate fast lenses? Is it actually for their low light ability or their sharpness?? Take for example the Nikon 50mm...everyone drools over the 1.4 but what does it REALISTICALLY do that the 1.8 cant? And further to this point...at 1.4, the DOF is so shallow that its just about useless (which is also the case at 1..

Post some pics that illustrate why huge $$ fast lenses are soooo drool worthy to the "average" photographer.

Well, dunno if I wanna get into this Xtreme thread or not....

But, I'll throw in my 2 cents.

Fast glass isn't just about the DOF. One of the things is that the faster the glass, the better for AF in low light, low contrast conditions. There's almost a full stop difference, which isn't trivial, if you need it.

Also, there are usually a number of differences between the fastest lenses and those a little slower. The Nikkor 50mm and 85mm lenses are the best examples. Both have f/1.4 and f/1.8 choices. In both cases, the f/1.4 models are better built and use different glass and/or coatings. The 50 f/1.8 is said to have a plastic mount, compared to a metal mount for the f/1.4, for example.

IIRC, in both cases, the f/1.4 lenses are sharper wide open than the f/1.8 lenses and remain that way until about f/4.

Having said all that, the question then becomes, would you notice the difference? Maybe so, maybe not. It depends on your shooting style and how much you pixel peep.

I bought the 50 f/1.4 and the 85 f/1.8, simply because the expense differences on the 50s was insignificant, unlike the price differences of the 85s.