harry__florida_
-
Posts
90 -
Joined
-
Last visited
Content Type
Profiles
Forums
Blogs
Events
Downloads
Gallery
Store
Posts posted by harry__florida_
-
-
I went back and retested my 50mm Aspheric on two M film bodies (new MP and newish Zeiss Icon) and at one meter and f1.4 (same conditions as used with the M8) the 18" mark on my yardstick on which I focused is perfectly sharp, using a microscope on the negative.
My question now is has anybody ever used a 50 Aspheric lens at f1.4 to do a focus test at one meter similar to mine on a M8 body?
-
Hello Cardy-
I greatly appreciated the comments from one who has actually done some similar testing. I agree fully with your comments on 57 vs 07.
My assumption of the lenses used being good was based on good results using them on various M film cameras.
It was interesting that so many bad lenses seemed to show the same problem, a true focus about 2cm to the rear at 1 meter. Was your M3 quite accurately calibrated, flange to film plane? Using the old formula 1/f = 1/u + 1/v as an approximation, it would seem that an error of about 50 microns or 0.05mm would account for that 2cm error.
-
Hi Dan-
I understand that "standard focus" of a lens by design is at infinity. But I do not understand how a user can determine if his lens is "indeed focused there."
I can determine if a lens is focused at one meter by looking at the image on the sensor plane of objects closer and farther away than one meter. See my second picture above. How do I determine focus at infinity without being able to place targets "beyond infinity"?
If you have ever had your eyes examined for glasses, you will recall that at the end they do not ask you which proposed prescription is sharper but to say when two adjacent powers of prescription are equally unsharp.
-
Hi Tony -
As I understand it, the "infinity adjustment" above has to do with setting a lens to the infinity mark and then adjusting the cam for coincidence in the finder of the two images seen of a target at/near infinity.
But my concern is the correct focus of the image presented at the film plane or sensor surface in the case of the M8 which of course is not affected by that adjustment. You can turn all the cams all you want and it has no effect on the actual image recorded.
-
My other image disappeared so here it is again, the result with the 50mm 1.4 Aspheric.
-
How would anybody know if the infinity focus is correct?
-
I know it is a problem and will return the camera. The point was to find out how common a problem it is.
-
Other tests would be meaningful in that they would show if few, some, many, most, or all M8's have the same problem.
-
Here are a couple of images depicting the rangefinder focus accuracy of a recent
M8 body using two late 50mm lenses known to provide accurate focus on a variety
of M film bodies. The lenses are a 2.8 Elmar and a 1.4 Aspheric, both used wide
open. The target is a yardstick placed at an angle to the camera and focus was
on the 18" mark at about 1 meter distance, using a tripod and 1.25x magnifier.
I made the test because my images seemed to be sharpest a bit behind the actual
focus point at most distances.
My interpretation of the resulting images is that at 1 meter distance, the (or
rather, this) M8 focuses about 2" behind the rangefinder-indicated point of focus.
As a side note, it would appear that the depth of field of the Elmar wide open
is close to equal behind and in front of the focus plane whereas with the Asph
wide open the depth of field is mostly behind the focus plane.
I wonder if other users have similar test images to contribute? If you use
mainly wide angle lenses and small apertures you might not notice this effect.<div>
</div> -
My experience over many decades of usage of Leitz/Leica lenses is that the materials used and machining/fitting workmanship from the 50's-60's were far superior giving much better mechanical performance though today's optics are clearly superior.
-
I am just starting today with an M8 and must be doing something wrong but can't
figure out what exactly. My impression had been that you could use lenses
without the UV/IR filter and only have problems in rare conditions like
synthetic black clothing under incandescent lighting. Here is what happens for me:
1) As a baseline, using a 35mm f2 Aspheric and proper E39 UV/IR filter, results
are quite nice.
2) However, using for instance a 50mm 1.4 Aspheric lens without filter (don't
have the proper size yet), it is as if the system does not see green at all. All
the green leaves outside my window come out drab brown. (The same for the 35 f2
without filter for that matter.)
3) White balance and lens detection have no effect on the lack of green.
4) I just downloaded and installed the firmware again but no change.
Where did I miss the boat?
-
I used to buy "code U" microscope equipment from Leitz and in that case the items were perfectly usable and may have been demos, dealer returns, discontinued, etc.
-
Actually it has probably the LOWEST price/performance ratio.
-
The later black Elmar is better than the earlier chrome version. And the later Focotar-2 is better than the earlier version. I have used both in your setup with good results. BTW, I find the earlier magnifier for the Visoflex II ( which fits the III when used on some cameras ) is easier to use for me wearing glasses.
-
Here's a recent sale of the Prado 250:
and here are a 250 and 500 that did not sell because the starting prices were too high:
and finally here is a superb Prado 66 outfit, hard to find for the 2 1/4 inch (6x6 cm) slide capability, which is far superior to your projector. This one sold for about $52 because it was quite special.
I have used Leitz/Leica projectors for 50 years, repair and make a market in them, and have the engineering background to judge their quality.
I will gladly sell to the other gentleman an unlimited quantity of the 250's and 500's at his stated prices if he will kindly email me his shipping address. How many do you want to start with?
-
eBay is usually a good source for prices for equipment like this. As well made as the Prado is, its older illumination system is not very efficient. You could ask for $50 and take $25 or more than that in trade? You could probably net more by selling the slide changer and lens separately and tossing the housing itself.
-
You could try stacking the five filters by screwing them into each other. Then you just need to cover the two ends. You can find 39mm end caps or a pair of unusable "junk" filters to protect the two exposed surfaces. This should minimize the total volume.
-
Why not ask your "friend" to spend his time to contact Leica and determine what a replacement solenoid would cost. Not much can go wrong with them; normally at most it would need to be rewound if no longer available. Has he no responsibility for losing it??
-
try searching on eBay using the term "eldia".
-
One last plug for the apo -- the last two which sold at auction, essentially like new, went for $501 and $599. You will find them readily available in or under that range. I got one for under $400 like new in the box.
-
The apo version as one would expect is a significantly better performer. It would be difficult to spend as much as $1K for one; I own two like new examples and spent less than that for the pair, bought a year apart. Look on the auction site.
-
Be forewarned that this return to the factory in Japan can take a L O N G time! Mine took over 3 months and had to be returned again the same day it arrived back so it has now been 5 months and counting. I did ask for and received a brand new loaner at the outset however and strongly suggest you do the same.
-
Doug, I was interested to see you use the apo extender with the 560. Any general comments on using it with that and other lenses? For instance, do I see a degradation in image quality (not in the least to criticize your beautiful results!!) of the 280/4 APO when using the extender compared to without? How do the results of cropping an image without the extender to match image size with the extender compare, and is there a dependence on the f stop used? Your patience with your art and love of the avian realm show in all your photos.
-
Isn't it the gadget to mount a R motor drive to a tripod?
Disable Summaron Infinity Lock
in Leica and Rangefinders
Posted