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  #11  
Old 05-01-2005, 05:49 AM
Darren Darren is offline
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Join Date: Mar 2003
Posts: 854
Default Re: lens question

Hey Sohrab. Actually, you should read: this. Also, if you go to the DOF calculator that your link gives, and plug in the numbers I gave you, you will see that the DOF in the cases I gave you will be the same. I will give you the results of a query I ran on that same DOF calculator. If I shoot something at f/4, from 72 inches away with a 100mm lens, the near focus limit will be 70.5 inches (obviously an American site), and the far focus limit will be 73.5 inches, with a total DOF of 3.0 inches. Now, if I shoot that same object with a 50mm lens, also at f/4, but from 36 inches away (so I get the same magnification), the near focus limit will be 34.6 inches and the far limit 37.6 inches for a total DOF of 3.0 inches. Same magnification, same aperture, different focal lengths, but the same DOF. You can try that link, or other DOF calculators on the net; they will all return the same types of results.

I went through this exercise a while ago when trying to get my head around this concept.

Take care
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  #12  
Old 05-01-2005, 06:04 AM
Darren Darren is offline
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Default Re: lens question

a Leica summicron (f/2) will always be more contrasty and technically "better" than a Summilux (f/1.4) : note this goes against Darren's opinion

I won't argue this Luko, it is one of the reasons I specifically mentioned the three Japanese brands (Canon, Nikon and Pentax), but didn't get into things German. Typically, a Japanese company will put their better glass, materials, etc into their f/1.4s than in their slower lenses. Another reason for my opinion of f/1.4 lenses producing more pleasing results has to do with the number of aperture blades used. For example, I recently upgraded my 50/1.7 to a 50/1.4. The 1.7 used 6 aperture blades, the 1.4 uses 8. This gives more a more circular set of highlights in the bokeh of the faster lens, even when used at the same aperture. The difference between my two 50mm is striking, IMO. I have to admit, I am surprised at how much I prefer the results from my 1.4. Also, although not as sharp or contrasty at f/1.4, I find that I can get pleasing results at f/1.4.

Just as an example, I can show you the very first shot I took as a 1.4 owner. It was handheld at something like 1/60th in a Starbuck's down the street from my camera store. It is by no means a great photo, but I do think it demonstrates acceptable sharpness and contrast at f/1.4 (although for a very shallow range), as well as a quite pleasing characteristic of bokeh (against an unchallenging background, admittidly). I am not doubting this would be surpassed by a Leica image, but I don't have a Leica to shoot with ;).
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  #13  
Old 05-03-2005, 07:51 PM
thien thien is offline
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Join Date: May 2003
Posts: 405
Default Re: lens question

pick me, pick me! Are you ready for this?

"pre AI" [F-mount + meter-coupling-shoe]: MOUNTING "pre AI" LENSES ON SOME CAMERAS CAN DAMAGE THEM; lenses not incorporating AI meter coupling "ridge" to indicate aperture ring setting to the meter ("pre AI" lenses have a "shoe" instead, this shoe is found on some later lenses); "pre AI" lenses include all lenses manufactured prior to 1977?; Nikon used to offer an upgrade service to convert older lenses to AI, but now this service is only offered by a few camera repair shops.

AI [F-mount + meter-coupling-shoe + AI-metering]: Lenses that incorporate AI metering feature introduced in 1977 (1978?)

Series E [F-mount + AI-metering]: Same as AIS (expect missing meter coupling shoe for "preAI" bodies), lenses in this series are less expensive andmarketed toward people who purchased the inexpensive EMbody

AI-S [F-mount + meter-coupling-shoe + AI-S-metering(=AI + something)]: Upgrade to AI standard - changes include:
1) a scoop that indicates if lens is 135mm or longer &
2) a tab on the lens to indicate maximum aperture(?) (this is outdated for CPU bodies as CPU lenses now indicate this electronically); offers some vague features to certain cameras, like: choosing high/low speed programs on FA, permits matrix metering on F4.

F3AF [F-mount + meter-coupling-shoe + AI-S-metering + AF-by-lens-motor]
Original AF offered in 1983; only 2 or 3 lenses in this series; can only AF on F3AF and F4, no other bodies have the software to drive their AF mechanisms; never really took off and Nikon forgot about AF until Minolta and others made a go at it years later.

AF [F-mount + AI-S-metering + AF-by-body-motor + CPU]: Newer AF introduced slightly after Minolta AF SLRs came out; first lenses to incorporate CPUs; unlike earlier F3AF lenses, these use a motor in the camera body to focus the lens

AI-P [F-mount + AI-S-metering + CPU]: Manual focus, but includes a CPU which is necessary for certain features on certain bodies; only lens in this series is 500mm f/4 EDIF P

AF-D [F-mount + AI-S-metering + CPU + AF-by-body-motor + distance-encoder]:
Upgrade to AF that includes an encoder to indicate how far way the subject is from the camera - this information is used for calculating exposure with the new matrix metering introduced with the N90, N90s and N70. N50 uses the distance encoder for ambient light metering only

AF-I [F-mount + AI-S-metering + CPU + AF-by-lens-motor + distance-encoder]:
New motor in lens style AF; only F4, N90s, N90 and N70 have software to drive their AF mechanisms; only the N90, N90s and N70 takes advantage of the distance encoding. N50 uses the distance encoder for ambient light metering only

AF-S [F-mount + AI-S-metering + CPU + AF-by-lens-silent-wave-motor + distance-encoder]: Silent wave motor in lens AF; only F4, N90s, N90 and N70 have software to drive their AF mechanisms; only the N90, N90s and N70 takes advantage of the distance encoding. N50 uses the distance encoder for ambient light metering only

CRC (Close Range Correction): designed to maintain good results even at closest focusing point

PC (Perspective control): allows lens to be "shifted" to correct converging verticals (to a certain degree); used for example to make buildings not appear to fall over backward when shooting up at them

Micro: Macro to every other manufacturer; lets you take extreme closeups of small objects.

ED: special glass to keep all colors focused together in telephoto lenses

IF: focusing is done inside the lens without front lens element moving

Noct: an f1.2 lens that can be shot wide open with good results; point light sources don't cause problems; meant for shooting at night?

D - Defocus control (not to be confused with AF-D)): let's you adjust where the depth-of-field is in relation to subject (instead of the normal 1/3 in front and 2/3's behind)
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  #14  
Old 05-03-2005, 07:57 PM
thien thien is offline
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Join Date: May 2003
Posts: 405
Default Re: lens question

.... and of course the latest and greatest

DX: Digital SLR lens specially made for the 1.5x factor sensor.

Most of Nikon lens can be mount on your Nikon body but some body features may not work. Please consult your Nikon manual for the proper usage of the lens (if you find it).

Canon owners, you can stop holding your breath now.
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  #15  
Old 05-03-2005, 10:53 PM
Luko Luko is offline
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Posts: 1,969
Default Re: lens question

oooh shite, GrandMaster Geek...you've spanked Darren's rearpart too heavily, your gearheaded majesty : he might not even want to talk gears anymore, I can see him crying in a corner, fathoming the distance to total nerdness...

Don't worry Darren, I'm sure Pentax also have plenty of initials on their lenses too... ;D
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  #16  
Old 05-03-2005, 11:26 PM
tongapup tongapup is offline
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Join Date: Jan 2005
Posts: 357
Default Re: lens question

this is what i like to see: bloodsport. if i'd been in ancient rome, you know where I'd have spent all my time. yes, i could have brought my damn lens into the shop, but i prefer some shirt-tearing and chest-thumping with my tech. how else can i stay interested?

actually, i trust you lot more than the folks at the shop -- after all, i've actually seen your photos.

thien, thorough is not even a strong enough word for that answer, thanks. it seems i could have avoided all this if i'd said my mum bought this camera in 1977. after looking at eBay, i must conclude that it's a nikon FM. when i twist the lens off the body, i can see a kind of nuclear-hazard-symbol-shaped metal ridge that fits into a similarly shaped groove in the body. i have a dread feeling this is a pre AI lens, which means I'm going to have to buy new lenses when i get a dSLR.

in which case i may as well get a canon, since all my heroes have canons.
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  #17  
Old 05-04-2005, 12:28 AM
thien thien is offline
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Join Date: May 2003
Posts: 405
Default Re: lens question

I actually plucked the Nikon information from a website so Darren you can stop crying now ;). The actual normal human view for a 35mm system is 42mm.

Lisan, if you will choose Canon, welcome to the dark side!!!!

Canon owners, please wipe off the smirk on your face. In the spirit of fairness, here are the Canon Da Vinci Codes:

USM (Ultrasonic Motor): These lenses are driven using ultrasonic oscillation energy. There are two types of USM, one is the ring-type USM which allows Full-Time Manual Focusing (FTM) without having to switch the lens control to manual mode. Micro USM does not allow FTM.

IS (Image Stabilizer): Gyro-control group of lenses are moved in the opposite direction of vibrations or movement to allow stable handheld pictures.

DO (Diffactive Optics): Special lenses with glass properties to produce telephoto lens that are much shorter and lighter than normal.

Macro: Close up photography

Soft Focus: Allow that nice blurring, dreamlike shots. There is one that ever made, the 135mm F/2 Soft Focus.

And the ever silent treatment of UD (UltraLow Dispersion), Super Low Dispersion glass, Fluorite elements, and Aspherical elements that never got mention on your lens. You have to read each lens specification to know if they are there in your lens. However, if you can mount a Canon lens on a Canon body, you are sure to get the AF and Exposure system works.
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  #18  
Old 05-05-2005, 04:05 AM
MKING MKING is offline
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Join Date: Dec 2003
Posts: 376
Default Sorry for this long-winded response...

Hi Lisan,

I own this particular lens (a manual focus Nikkor 50mm f/1.4 AI from about 1979-80). The optical design hasn't changed in thirty years (and is even similar to the 50mm that made Nikon famous-- the 50mm f/1.4 from their rangefinder series in the 1950sp; arguably better than the Leica 50mm of the day!). It's a bit fuzzy at f/1.4-- the shallow DOF contributing to this with some light fall off on the edges, but by f/2.8 is quite sharp and by f/4-5.6 is like a razor blade. Brilliant edge contrast and resolving power. Stopped down past f/11 and it declines and its not great at infinity focus either. It's really optimised as a low-light/ wide aperture lens.

It may or may not mount onto a Nikon DSLR down the track (I'm assuming your question is a round-about way of getting some advice on picking a DSLR system too :) ) but if it does you won't have metering with the mid-range bodies like the D70 or the starter D50. Not really a factor since there's the brilliant (and inexpensive) 50mm f/1.8AFD for sale which is just as good as the f/1.4 at mid apertures and even better stopped down. This is the popular mid-portrait lens on TE. (The AFD 50mm 1.4 is $600 in Australia new!).

Nikon system compatability has shifted in the last decade from mutual compatability between old and new to new working with old but not vice versa to new not working with old at all (not aperture rings!) and old not really working all that well with new (no metering). They're really becoming two separate systems that happen to share the same lens mount. You'll often find nostalgic Nikon shooters buying old manual cameras like the F3, FM2, FM, FM3a and buying a few, inexpensive but brilliant manual focus fixed focal length lenses to build a separate, mini system. (The 105mm f/2.5 and 28mm f/2.8 are the most popular choices).

I say, don't let your 50mm lens pick your system-- go to the shops and play with the DSLR offerings from Nikon, Pentax, Canon, Minolta and see which one feels best in your hands and takes the least amount of effort to figure out; Nikon and Canon offer the broadest selection of self-branded lenses within the reasonable focal lengths of 18 to 200mm but the third party stuff is also getting quite good these days too considering the price.

Keep using the old Nikon if it works though with some nice print film (eg, Fuji Superia 200 or 400 or, for a bit more, Kodak Supra 200 and 400). Or even some C41 b/w film (Ilford XP2 is my favourite). Get a good lab around to scan them at high resolution with no contrast corrections and then take them home to post process. Working with film taught me more about photoshop than working with digital files...

Check out here for some pictures on TE taken with a Nikkor 50mm f/1.4

Cheers,

Mike
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