This thread is no longer about what lens the D400 will be announced with. It's gone waaaay off-topic.

I'm sorry but no one seems to be getting the point or the discussion started by DxoLabs ( f-stop blues ) and Mark Dubayov (?) ( open letter to camera manufacturers in Luminious Landscapes - a link also provided here in NR a year ago ).

The lenses are what they say . f1.2 is f1.2 , f1.4 is f1.4, f1.8 is f1.8 ... No tricks there and nobody has any conspiracy theories about lens apertures.

The whole discussion is about the SENSORS'(Underlined) INABILITY to read light passing at WIDE OPEN apertures ( nothing to do with the lens ) . I think it is best to check what the articles say .

Vidrazor - you are right they won't be exactly the same - so as the "moving iso theory" goes, the camera moves the iso up a bit to match what the perfect world numbers should be - BUT it hides it from the user. So to reach the perfect world numerical calculation the iso is bumped from 200 (perfect numbers) to 220 but the EXIF reads 200.

What some have questioned is if the companies are cheating lenses saying they are 1.4 when they are actually 1.5/1.6/1.7 and making up the difference with the sensor hiding it. I think that is just another conspiracy theory for those who need them to get through their day.

I do believe the lenses are what they sate. I also believe that the sensors can not always achieve a perfect 200/400/800. And really who cares?

Paperman said:
I don't get what you mean . f1.4 should allow exactly 8 tımes more light to pass through which will then be balanced by the 8 times faster shutter speed so "theoretically" there should be no difference in light transmitted thru the lens.

What is "sensed" by the sensor is what we are trying to find out. Best to see the test first and then talk.

Well, that's exactly my point. It WON'T be exactly the same. There will be differences due to the mechanical nature of the aperture blades. That's why you want to know what those differences are, and they'll show up on film. Everything else then would be a product of the sensor (or not).

vidrazor said:... but the transmission differences between f1.4 and f4 also have to be taken into account.

I don't get what you mean . f1.4 should allow exactly 8 tımes more light to pass through which will then be balanced by the 8 times faster shutter speed so "theoretically" there should be no difference in light transmitted thru the lens.

What is "sensed" by the sensor is what we are trying to find out. Best to see the test first and then talk.

>>The problem is not the lens but the sensor which can not read the light passing alongside wide open aperture blades . There will be no difference if the test was done on film.<<

Well I meant to map the transmission differences between f1.4 and f4. Because my 50mm is MF, the camera can't "cheat" at modifying the ISO so if you're correct then you will see a difference, but the transmission differences between f1.4 and f4 also have to be taken into account.

@Vidrazor,
TTJ has explained what I meant with the only difference being the mentioned ISO boosting being from (let's say ) ISO 200 to ISO 300/ISO 400 and not to ISO 210. We're talking anywhere from 0.3 stops to 1.0 full stop depending on pixel density.

vidrazor said:

Any particular reason the test you outlined should be carried out at ISO 200? Is ISO 100 on the Nikons a clamped ISO setting?

No reason,just chose to mention an ISO value to make sure it is fixed for both shots( and thought you had a D5000 with a base ISO of 200 ). ISO 100 is also fine of course

vidrazor said:
The problem I see with your test is that at f1.4 there will be significant falloff at the the edges of the live area, so the image will look darker somewhat. The DX frame would minimize this somewhat. The central part should remain more or less the same.

That would be vignetting and I'm not talking about that. The whole frame supposedly will be underexposed at f1.4 and not just the corners.

vidrazor said:
Perhaps replicating the test with a film camera to see where a particular lens lies would help "map" the lens (at least those like my 50mm that can work on film cameras).

The problem is not the lens but the sensor which can not read the light passing alongside wide open aperture blades . There will be no difference if the test was done on film.

>>Then you can do the test I'm talking about with your AI-S 50mm f1.4. ( I'm not sure what you are testing with the way you explained.)<<

My test was merely shooting an identical set of images at ISO 100 in manual mode with a fixed shutter speed while opening up one stop at a time until I hit f1.4.

Any particular reason the test you outlined should be carried out at ISO 200? Is ISO 100 on the Nikons a clamped ISO setting?

The problem I see with your test is that at f1.4 there will be significant falloff at the the edges of the live area, so the image will look darker somewhat. The DX frame would minimize this somewhat. The central part should remain more or less the same.

I think you would also have to take mechanical aperture differences into account as well. So I don't think it will ever be exact. Perhaps replicating the test with a film camera to see where a particular lens lies would help "map" the lens (at least those like my 50mm that can work on film cameras).

However I'll try your test out as you've detailed it, and see what happens.

@vidrazor - What paperman is referring to is that testing companies have found that when a lens says it is open at 1.4, at iso 200 at a shutter of 1/60 (example) they have found that the tested iso is being bumped to 210 (+/-) but still being posted in the file as 200. The two questions that come up is that if 1.4 is actually 1.4 and the sensor is off or if the lens is not gathering all of the 1.4 light and the sensor is adjusting to make one think that it is. There are many ideas of what it is, but no one has been able to make a hard fast "why is that."

My thought is that there are always tolerances (+/-) on sensors and lenses and metering can make a difference as well. Does it really change any quality or the way I shoot - nope - so I really don't think twice about it.

vidrazor said:
>>
I'm not sure what's being addressed here. I just put my D5100 into manual mode, threw on my MF 50mm f1.4 AI lens and shot a series of images at the same shutter speed opening up a stop at a time up to f1.4. Results were quite predictable.

Then you can do the test I'm talking about with your AI-S 50mm f1.4. ( I'm not sure what you are testing with the way you explained.)

Take any shot - preferably just a white blank sheet of paper in Manual at ISO 200 (Auto ISO OFF! ) - twice :

- one at f1.4 1/500
- one at f4 1/60

Both are same EV value so theoretically the results should be the same ( the shutter speeds are just there to give an idea . If there s too little/too much light , feel free to change them - as long as they are 3 fstops apart . )

There are those who say the shot at f1.4 will be exposed less than the one at f4 .

You can check the two shots / compare histograms if necessary and let us know the result .

>>The digital sensors' inability to utilize all the light passing thru wide open apertures - unfortunately - is not limited only to f1.2 lenses . f1.4 lens tests have shown similar results & tweaked ISOs , though only in the 0.3-0.5 EV range ( f1.4 said to be actually being equal to f1.7/f1.8 for most sensors/pixel densities ).

Not a subject many of us would like to hear/think about ; so better cut short :-)<<

I'm not sure what's being addressed here. I just put my D5100 into manual mode, threw on my MF 50mm f1.4 AI lens and shot a series of images at the same shutter speed opening up a stop at a time up to f1.4. Results were quite predictable.

As for relying on higher ISOs with today's sensors, while you certainly get perfectly usable images at higher ISOs, seems to me the moment I hit ISO 400 on my D5100 noise is already more apparent than I'd like it to be. So if I have the option to shoot a scene with a faster optic and a lower ISO, I'll take that any day over relying on cranking up the amplifiers in my D5100.

@shigzeo,

Could you do a test ( related to the subject ) with your Nikon f1.2 if I ask ?

TaoTeJared said:
Neither. I don't think we will see a 50mm f/1.2 anytime soon. In practical terms it is not much different than the 1.4 except you will miss focus on more shots.

Pretty accurate. I have the 1,2 50 Ai and it is great, but I rarely, if ever use F1,2. Focus isn't a problem if you shoot on angles, but shooting straight on (like brick walls) is almost impossible as the focus plane is very thin. A poorly placed breath will push you out. Now, change your angle so that you are jibing away from the wall somewhat, and you will get 100% perfect focus almost all the time, but 1,2 on the current 1,2 50 Ai/AiS isn't all that great; lots of abberrations to deal with.

I have seen some images from the canon 50 1.2 and there is a very nice dreamy quality to it.. however, that does not mean the same attributes will be in any new nikon 50mm 1.2. the old nikkor 50 1.2 and the nikkor noct 58 1.2 had different feels to them as well.

adamz: yes, I understand some people want the 2.8 telephotos and the f1.2 50mm to obtain a shallow depth of field. Question, is the DOF from a f1.2 lens really that distinguishable from the DOF of a f1.4 lens? I hardly think it could make much difference.

There are three "needs" for fast lenses: DOF; low light shooting (like candlelight or restaurants) and high shutter speed (like high school basketball) to freeze action. I don't know what percentage of people from each group buy those lenses. My understanding was the fast telephotos were mostly purchased to freeze the movement of wildlife or sports and the fast normal lenses were mostly purchased to shoot in low light. I have not heard of anyone, except you, feeling a need for a f1.2 lens to obtain shallow depth of field in normal light. Perhaps you are right. Maybe whatever we think most people want just depends upon our own experiences, interests and perceived "needs."

Paperman said:
The digital sensors' inability to utilize all the light passing thru wide open apertures - unfortunately - is not limited only to f1.2 lenses...Not a subject many of us would like to hear/think about ; so better cut short :-)

The whole "sensor tweaking iso values" I believe it just a normal expected effect of of moving to digital. When it comes down to it, if the iso is bumped 10, 25, 50 but the image quality doesn't suffer, the ideology argument of companies hiding it gives way to the practical real world use where it doesn't matter. I don't like seeing it, but if it took a huge computer with many instruments to find something the human eye can't - I don't see the point on dwelling on it.

donaldejose said:
Nikon exists to make money. It will produce any lens it feels will sell in sufficient quantity to reap a profit from the development and production costs.

I couldn't agree more. They are there to make money - not keep everyone under the sky happy.

@donaldejose - most of the ppl who buy 50/1.2 are doing it primarily for shallower DOV not because they can gain some speed

Part of it has to do with how economics have changed too. Once upon a time corporations innovated their products so that their followers would come back and brag and bring more followers in. We told them what we wanted and we often got what we wanted.

Now unless we scream at them to fix something they usually don't budge because everything is based off stats and projections not current demands from the customer. Is there really any other way to explain the 40mm f2.8 micro?

i wouldn't consider it....

Nikon exists to make money. It will produce any lens it feels will sell in sufficient quantity to reap a profit from the development and production costs.

Back in the slow film days when we were mostly limited to ISOs ranging from 25 to 400 a 50mm f1.2 lens was attractive and the added light transmission seemed useful. There is probably a small group of photographers who still remember the "halo" or "reputation" or "wow factor" or whatever of a 50mm f1.2 lens and therefore still find one desirable. However, I believe digital sensors have pretty much eliminated any value to be gained from less than half a stop additional light gathering because it is so easy to simply increase the ISO a bit to equate to less than half a stop additional light. Sensor low light performance is increasing with each new generation of camera body. In a way, each improved sensor is like increasing the largest f stop on all our existing lenses.

Only a very small number of people who want to "shoot in the dark" or use extreme shallow depth of field will actually have a use for a 50mm f1.2. For people taking the "normal range" of photographs, a slight increase in ISO with a 50mm f1.4 lens can give you the same low light performance of a 50mm f1.2 lens. I agree with TaoTeJared's analysis of the subject.

However, Nikon is almost sure to produce one since they went through enough effort to develop one and patent it. So it will come and people will buy it and most of those people will actually have no real need or use for it!

I was wondering about the iso "bumping" issue when using fast lenses. It seems to me that it could only be an issue on cameras that communicate aperture values - otherwise the camera would just bump shutter speed in aperture priority or do whatever you told it to do in manual. My GF1 gets more light at f/1.2 than at f/2 with my 50mm ais - and the camera has no idea that a lens is even attached - leading me to believe that there is still some advantage to faster lenses even if the larger apertures are not fully utilized as well as with film. As far as dof differences go - the 35 f/1.4, 50 f/1.2, and 105 f/1.8 all show shallower dof and more blurred oof areas wide open than stopped to f/2 or more - on both the D200 and the GF1. I understand that dof advantages should be somewhat lost with wide apertures and digital sensors, but I still see a difference in pictures, so I'm not too worried about it.
I think a 50mm f/1.2G is a great idea, especially if it's a top performer. I wouldn't be willing to shell out the cash for one though - especially when I picked up a full set of fast nikkor mf primes and a katz eye split prism screen for less than the cost of a new 35 1.4G. Maybe if I wasn't paying for university right now it would be a different story though...

Another question- remember that article that admin posted about digital cameras cheat with faster lenses by bumping ISO without you knowing it? Did anyone ever follow up with that?

I mean, I'm pretty sure I'm shooting at 1.2 if it's a non-chipped AI-S lens. :D

Isn't it odd that the Canon 85mm 1.2 autofocuses slowly but the 200 F2 is a great sporting lens? It's probably not a linear thing right?

The digital sensors' inability to utilize all the light passing thru wide open apertures - unfortunately - is not limited only to f1.2 lenses . f1.4 lens tests have shown similar results & tweaked ISOs , though only in the 0.3-0.5 EV range ( f1.4 said to be actually being equal to f1.7/f1.8 for most sensors/pixel densities ).

Not a subject many of us would like to hear/think about ; so better cut short :-)

SquamishPhoto said:
You don't seem to realize that your opinion isn't what matters here. AF speed, build quality and lens size & lens density are the main things that differ between the expensive lenses and the ones you seem to think work exactly the same. The 200mm F2 ...

Rather odd & aggravated reply. I said nothing to the point, but I also believe the more expensive (better built) lenses are better and never implied anything to the contrary. I have no issues with the 200mm.

So you can justify the advantages of your G over the D, but for some reason it eludes you that the difference between the G&D and the potential new 1.2 might be just as significant?

At a minimum, what I'm sure most would agree on, is that there is not all "that much" difference between the D & G in images. The G does have a more round Bokeh - I find that more pleasing and that is the main reason I bought it. So if the 1.2 is "Just as significant" it really wouldn't be worth it. If it does come to fruition, I hope that isn't the case.

I do understand the arguments for a 1.2, TS, DC and other exotic lenses. I wish I had $100k sitting around to buy them all. I think Paperman, PB PM, & donaldejose all have good points on the actual gain of 1.2 or Nikon's focus on a lens rather than others. If it is close to the Canon's 1.2 at $1,500, I'm not sure how much gain it could reasonably have over the 1.4 to justify $900-1000 more.

A quick search came up with close to a dozen patents for lenses and why this particular one seems more desirable than other's seems elusive.

heartyfisher said:
I don't know if nikon has "fixed" it in the new D4/D400 sensors but remember that the lenses below F2.0 don't really give you increased light gathering advantage as the sensor is not able to "see" some of the light coming from the more acute angles.. the camera manufactures cheat by upping the ISO a little. Both Nikon and canon and others too do it. However, I believe that you do get most of the reduced DOF of the wider apertures.

Paperman said:
Digital sensors have been proven in tests/articles to be not benefiting fully from the light transmitted thru a f1.2 lens ( as discussed last year in this forum ). We are talking about a loss of 0.4 to 1 full stop depending on pixel size ( recovered by ISO boost without knowledge of user ).

So maybe an f1.2 lens is not really something to get excited about ( other than the shallow DOF it brings )

I used to think that the DOF is not lost .. but thinking about it more .. maybe you do loose the DOF advantage as well.. bec if you cant see the extra stop of light from F1.8 to F1.2 then it must be lost from the edges of the aperture that increase the DOF ..

So unless the new sensors of the D4 and D400 negates this effect . a F1.2 lense is pointless.. on DSLRS (Film would be fine..) I wonder how the canon people feel now about their expensive F1.2 50mm lens that doesnt really give them what it says it does.. maybe thats why nikon has not come out with their new nocts and other 1.2 lenses for so long.. they just dont provide the advantages that they had on film. I think that speaks well for the nikon systems that they dont always bow to the "Marketing" preasures to include redundant functions or features.