alan_wilder1

WTB a clean +0.50 D eyepeice correction for M series.

Having used the 135/4 T.E., 135/3.4 APO and early and late 135/2.8 lenses, I prefer the late 135/2.8 for two reasons: sharpness and focusing accuracy, both of which go hand in hand. The slower 135's were tack sharp but only if RF calibration was dead on and focusing was very critical. Aside from the magnifying goggles, both 135/2.8's can be easily "tweaked" by the user for precise focus callibration using the vertical and horizontal adjustment screws on the side of the round goggle assuming the camera's RF adjustment is correct. It cannot be overstated enough that to get the best out of any lens over 50mm that focus callibration should be dead on especially high speed telephotos. What I like about the goggles is the ability to independently callibrate lens RF accuracy if I know my camera's RF is accurate. The later 135/2.8 is noticably better of the two due to impoved contrast and has a more robust goggle construction. Having said this, I would rate the 135/3.4 or 135/4 as best overall PROVIDED that the RF coupling was exact and a HM or M3 viewfinder was used in conjuntion with the 1.25x magnifier due to compactness and a trace improvement in sharpness. Keep in mind though that the 135/2.8's benefits from the same setup giving you even better focusing accuracy in poor lighting than the other lenses.

Regarding focus shift, I bracketed my focus in 1 mm steps towards the right at each stop from F/1 thru F/4. Central sharpness peaked at 2-3 mm focus scale shift but at the expense of off axis sharpness in the form of increased astigmatism. BTW 1 mm of focus ring rotation equals about 30 microns of lens displacement. Sorry I can't send my images but I have no scanner. I work at Johns Hopkins hospital in Baltimore.

In response to Antonio the lens has both spherical abberation( s.a.) and curvature of field( c.o.f.). Erwin Puts quantified the spherical abberation as being rather high. This abberation causes the lens' focal point to shift behind the film plane as the lens is stopped down due to elimination of rays from the outer portions that focus at the film plane. Curvature of field, prevalent in very fast lenses, causes off axis rays to focus in front of the film plane, increasing as you move further off axis or get closer to the subject. My theory is they tend to cancel each other out to a degree just off axis since they act in opposite directions. This probably accounts for the superior imaging between radii of 3-8 mm. I somehow doubt that s.a. is as bad as Erwin Puts says it is because he only measured 1% MTF40 contrast at F/2 without refocusing. If that were the case, central imaging would be pretty poor at longer distances where c.o.f. is less. Maybe later samples have less s.a. than the one he tested in 1998. BTW I measured MTF40 on film using Norman Koren's test charts found at his web site. They work pretty good since my results closely match Photodo test results on other lenses I've tested. One last point. Why use an F/1 lens when you can use a Summilux and faster film? I mostly use slide film, preferably Velvia or Provia 100. They can easily be pushed to 200 but if you need ISO 400, Provia 400 is good but not as vibrant as the slower film. At the other end of the spectrum if you want to record comet tails and don't want streaks due to long exposure times(> 13sec.), you'll need the extra stop to record detail without pushing film past ISO 800.

After recently purchasing a near mint latest 50/1 Noctilux, I ran

some test rolls of T Max 100 and Velvia 100 to determine whether or

not to keep it. Reading on line comments by subscribers and

extensive tests by Erwin Puts certainly peaked my curiosity. Since I

already own a mint german tabbed Summicron, a Summilux's gain of

only a stop seemed of little benefit and the 50/1.2 while 3/8 stop

faster than the Summilux has a high price tag and lack of filter

threads for front element protection (unless the hood is used) was

also a turn off.

 

My results were a pleasantly suprising.

> At F/1 the image is a little soft but quite usable with resolution

of 40-44 lp/mm and MTF40 of 40% to an image radius of about 8mm.

Outside this, the image softens to an average of 22 lp/mm and MTF40

contrast of 20% except at the edge(18mm radius) where resolution

rises to 40 lp/mm and contrast to 40%.

 

> At F/1.4 the figures are similar except central contrast jumps to

MTF40 of 50%.

 

> At F/2 resolution increases to 50 lp/mm and MTF40 contrast

increases to 55% with an image radius of about 8mm. Outside this

resolution remains about the same as before but contrast rises to

25% and 45% at the edge.

 

> At F/2.8 resolution decreases to 44 lp/mm and MTF40 contrast drops

slightly to 50% WITHIN a 3mm radius due to spherical abberation. By

8mm radius it increases to 64 lp/mm and outside 8mm resolution goes

to about 36 lp/mm and contrast to 45% except the edge with 50 lp/mm

and 55% contrast.

 

> At F/4 central resolution rises to 50 lp/mm and MTF40 contrast is

55% within a 3mm radius but by a 10mm radius, resolution is 80 lp/mm

and MTF40 contrast is 55%. Beyond 10mm resolution drops to about 56

lp/mm except the corner at 28 lp/mm due to astigmatism. Contrast

rises to 60% except the edge at 70%.

 

> At F/5.6 central resolution rises to 64 lp/mm and MTF40 contrast

of 60% within a 3mm radius and about 80 lp/mm and 65% contrast for

the rest of the frame except the corner at 50 lp/mm.

 

How does it compare to the Summicron? The Summicron was better

centrally and at the corners at all apertures. Between 3-10mm image

radius the Noctilux matched and mostly excelled in resolution and

contrast over the Summicron. In the outer zones( 9-15mm image

radius) the Summicron was a little better at F/2-2.8 but by F/4-5.6,

the Noctilux was the better. Vignetting was about the same at

comparable apertures. Lens testing was done at 1:51 or about 8 1/2

ft. When tested at much longer distances, the defficiences noted

with the Noctilux were even less apparent. At F/2 the Noctilux out

perfomed the Summicron in the 3-9mm zone at subject 50-100 ft. away.

Also notable was the superior flare and ghost image suppression of

the Noctilux. The Summicron at F/2 with its vented hood produced a

typical orange ghost image from the sun outside the lens field while

the Noctilux with it useless built-in hood was free of ghosts at F/2.

 

How do these results square with what reviews written about the

lens? My guess is that up to F/4 spherical abberation while

degrading central perfomance becomes "neutralized" by competing

abberations( such as curvature of field) outside a 3mm core so that

images within the 3-9mm zone are rendered very nicely. By F/5.6

depth of focus and further supression of abberation takes over. BTW

to test spherical abberation, I deliberatly defocused in steps and

found that central sharpness certainly increased but at the expense

of all sharpness outside the central zone. I'd prefer a sharper

image just outside dead center as this is where you place a subject

following the "rule of thirds" in composition.

 

Based on these results, the Noctilux is worth keeping as a lens best

used for late afternoon through early evening, general low light

applications, telephoto-like isolation at F/1 and uniform critical

sharpness from F/5.6 on. The Summicron is great all purpose lens due

to it's critical sharpness and closer focus in a handy size.

Has anyone actually compared these lenses for perfomance and

fingerprint? I understand the 50/1.0 has a significant focus shift

due to sph. aberration but as per Pop. Photography(5/76) the 50/1.2

has none. I currently have a 50/2 which I will keep and I'm looking

to supplement it with a low light lens. I like the size and weight

of the 50/1.2 but ultimately optical performance is key.

I have tested both and under the right shooting situations their is a noticable difference. Specically, if you photograph a large leafy tree (filling most of the frame) and a setting sun behind it shooting its rays through the openings between the leaves and branches. What is plainly obvious is the shadow preservation of the dark portions of the tree in the current version compared to shades of grey filling in the shadows with version 11817 regardless of aperture. The current version consequently has more "bite" due to it's greater flare supression. Flatness of field was better from about 1/2 out to the edge of the frame with the current version. This is preferable with landscapes but curvature of field works to your advantage when maximizing DOF for off-center object closer to the camera. Color cast was more neutral with the current version while 11817 was a touch warmer. Handling the 11817, I liked it's smoother longer focus throw to the faster throw in the current version. Therefore, upgrading will primarily be based on better veiling flare suppression and less curvature of field of the current version. NOTE: my "current version" is the german tabbed lens with the detachable hood.

Can anybody give me information on a transparency viewer made by

Leica/Leitz in the 1950's or 1960's with a large swing out viewing

objective and is AC powered with a bayonet frosted bulb. It accepts

2x2 slides in either horizontal or vertical orientation. What is the

model designation and availability?

To address Charles' point, I have found that the difference in focus scale displacement between over a 1/4 mile and "true" infinity like the moon is about 1/5 mm or the thickness of an engraved line on a lens barrel when dealing with a short throw lens. In the case of the 90/4 M-E-M, it over-focused by at least 1 mm. This was enough to cause noticable rf patch separation at the infinity stop on the lens. Whats more significant is that a 1 mm shift of the focus ring displaces the optical unit about 250 microns which will be outside the zone of critical focus unless stopped down at least 3 stops. BTW I tried the lens on a recent production MP and M7 with similar results as the older M7 mentioned earlier.

To clarify a couple of points, the distance target was sufficiently far off( about 1/4 mile or more) and the rangefinder image over-focus displacement was significant enough where a target further away would have little or no consequence. Keep in mind that the 1+ mm "over-focus" on this lens would be equivalent to 2-3 mm on a 90/2 since the focusing ring throw is twice as great on the 90/2. I did note that slightly "dismounting" the the lens from where it clicks home acheived infinity focus as a function of the sloped cam. My other lenses accuratly focus with the sample body, so I doubt if the is fault with the infinity set point of the ecentric screw of the cam roller. The ser.# of the sample body pre-dates the patch flare modification, so could this make any difference when I try the lens on my soon to arrive MP?

I've noticed that my new 90/4 M-E-M focuses past infinity by a

little over one millimeter on the focus scale when used with a

dealers new 0.72 M7(ser.278xxx) while my other M lenses were spot on

at infinity. This is actually quite a bit because the 90/4 M-E-M has

a very short throw. The lens cam is sloped and not flat as in all M

lenses( except CL lenses). Does this mean the camera's horizontal

cam position is the culprit or is it an early lens defect? I'm

actually waiting for delivery of an MP and I wonder if it will make

any difference. Anyone have a similar experience?

Question for Bill(9/12/03 response). Please elaborate on "cheap" appearance of the M7 ISO dial on recent MP's. Is fit or finish an issue or is it just less cluttered by elliminating DIN settings? I'm curious because I plan on getting an MP soon. Thanks.

Thanks Ray. BTW can ITOOY be mounted in reverse for compact storage on the 11817 'cron?

Does anyone know if hood ITOOY will vignette when used on the 50

Summicron 11817?