RF accuracy chart

[splitimageview]

Spreadsheet is here

 

[ferider]

OK, here's a new chart with limit lines for common bodies.

Tres cool, John !

 

[Roberto]

Now.. we need to add all of the FSU cameras... 😱

 

[ampguy]

Yes

Yes

CL and lens were CLA'd at the same time. Close focus at f2 hit rate was maybe 80-90%, partially IMHO due to smaller patch RF than larger M's and trying to use it indoors. Worked perfect at F2 on later larger M's and 2 RD1s.

I don't know what to say about the RD1 and 75/1.4, it's not 100%, but you can see for yourself here:

http://matsumura.smugmug.com/gallery/4353480_KxbjR#255483561

Indeed it is not normal at all. At f/1.4 your 75 is way out of the accuracy range of the Epson. It is even very difficult to focus on the M8. Also, the .72x M6 has a longer EBL than the R-D1 (w/o magnifier) and the 40/2 should not have any problem with your CL at any aperture IMHO. Did you have the 40/2 cla'd as well?

 

[ampguy]

Hi Mike

Hi Mike

I specifically went around shooting objects close up and wide open:

http://matsumura.smugmug.com/gallery/4353480_KxbjR#255483561

You do need some kind of contrasting patch, but I find that is necessary with most lens.

The M6 focuses it easier, but by no means is it not possible to focus close up and wide open on an RD1, in my experience.

Next beer get together, I'll give a master class in "Focusing the 75/1.4 Lux" 😀


http://matsumura.smugmug.com/gallery/4353480_KxbjR#255483561

Ted, are you framing your subjects for the 75mm like you would with the 50mm? (i.e. farther away from your subjects with the 75mm)

 

[ferider]

Next beer get together, I'll give a master class in "Focusing the 75/1.4 Lux" 😀

Well, it might be the cigarettes, coffee, beer and other vices, but I have even
difficulties on the M6. The M3 is the right base for bertha 🙂

 

[LCT]

...Note that the above table does not account for minimum focus. For example, the 135/2.8 focuses down to 1.5m (? out of memory)...

Do you refer to the Elmarit 135/2.8? If so the minimum distance is indeed 1.5 meter but i wonder if your table takes its goggles into account on Leica M cameras.
Great job anyway.
Edit: Not sure if the goggles mag. is 1.4x according to Cameraquest or 1.5x according to my aging memory.

 

[ampguy]

Just curious, what would it take to show you folks that I can focus the 75/1.4 lux on the RD1 at f2 with 99% accuracy, and maybe you will consider gradients instead of making Bessa owners mistakenly think that long lenses wide open are impossible to focus accurately?

 

[edhohoho]

Just curious, what would it take to show you folks that I can focus the 75/1.4 lux on the RD1 at f2 with 99% accuracy, and maybe you will consider gradients instead of making Bessa owners mistakenly think that long lenses wide open are impossible to focus accurately?

I agree, Ted. I really don't know why people don't seem to believe us when we say that using the 75 Summilux at f1.4 on the R-D1 is not that hard, especially with a magnifier. I thought that rangefinder base length was only a relative guide, not absolute. In fact, I got the 75 Summilux for the R-D1 despite common knowledge regarding the R-D1's short base length and very little being written on the combination. I don't care whether someone decides to get the lens or not, but I hate to see this great combination be maligned and people dissuaded from it due to skepticism and fear rather as opposed to real user experience (including experience other than one's own).

 

[ferider]

Guys, the table shows that 75/2 is focusable on RD1 with magnifier, and R3 without. Plus a digital camera always allows you to check if you hit focus. - a huge advantage.

Nobody maligns anything. The table just shows values of a mathematical text book approximation. It does not include that focusability is highly minimum focus, person and camera body dependent (backlash). And not everybody focuses the Summilux at .7m (I do though). At minimum focus that lens has around 1cm DOF (on film) ! At infinity, you can focus any lens on a body with 0 EBL.

LCT, you are right, the 135/2.8 googles amplify by 1.5 ( = 135/90). Should correct that in the next version of the table.

Roland.

 

[ampguy]

Thanks Ed and Roland

Thanks Ed and Roland

The thing is, that I can absolutely 100% focus at f2 on the RD1 close and wide, and 99% @ 1.4 if I concentrate (give me 20 seconds and something of contrast, just as what I would need with an M3 with magnifier...).

I think it's a little bit wacky to do these binary thumbs up/down, green red, when *without* magnifier I can certainly focus some of these lenses at the specified thumbs down or red areas.

I think your taking "e" or "m" values for granted as constants might be throwing you guys off.

If I were new to rangefinders and saw your charts, I'd run away from Bessas, but having used them, I know they're capapble with my eyes, and my aligned lenses and bodies, of critical focus in some of the red areas.

Guys, the table shows that 75/2 is focusable on RD1 with magnifier, and R3 without. Plus a digital camera always allows you to check if you hit focus. - a huge advantage.

And not everybody focuses the Summilux often at .7m (I do though).

Roland.

 

[edhohoho]

Guys, the table shows that 75/2 is focusable on RD1 with magnifier, and R3 without. Plus a digital camera always allows you to check if you hit focus. - a huge advantage.

And not everybody focuses the Summilux often at .7m (I do though).

Roland.

But I believe some of us are saying that it is possible to focus the 75 Summilux at f1.4 and f2.0 without a magnifier. Even with a magnifier, it is more than possible to use the 75 Summilux at f1.4 because that's the aperture at which I most often use it. Regardless, I'm happy with my experience with the 75 Summilux and the R-D1 whether you think it's real or just dumb luck.

 

[ampguy]

Here's another question for you graph makers:

What are the symptoms or feedback to the user of not being able to focus accurately?

Does it appear to focus in the vf, but the image comes out unfocused? Is it back focused or front focused, or does the image just come out black?

Or does the an LCD sign show in up the VF saying "Sorry, invalid range for this cheapo camera and that f-stop, try another" 😀

 

[ferider]

No free beer for you at our next get together, Ted 😀 I think you should finally get yourself that M8 ....

 

[ampguy]

Hi Roland

Hi Roland

On second thought, (just played with dofmaster), I think the values may be right, I get 1cm of DOF at 1m @ f1.4 with the 75mm on the RD1.

This is what I notice, I have to pick whether I want the nose or eyes or ears in focus at min. focus on both people and especially the cat, and realize that if I move off center that I'm likely moving out of that 1cm range.

I guess I could take a sequence of 20-30 or more photos and show you that I capable of getting most right on at f1.4, or all of them (unless some major operator error) at f2.0 with the 75/1.4 lens.

If you added +/- 5 or 10% into your calculations, would the RD1 without magnifier be green at f2.0 with 75mm?

If so, maybe a yellow color or thumbs sideways at +/- x %??

 

[ampguy]

Lol!

Lol!

Well we should do the focusing demo before the beer 😀

I think the M8 doesn't have enough pixels. We just got back a 20" x 30" $9.95 poster from Costco from the kids 7MP A550, so I think there may be something to big enlargements and huge amounts of pixels.

The quality of this poster image is equal to that of those Paris/Britney ones at Kmart, very sharp.

I think I need 12MP, am looking at the A650IS and S950IS, I don't need the G9, that has raw mode, I don't do raw.

No free beer for you at our next get together, Ted 😀 I think you should finally get yourself that M8 ....

 

[ampguy]

German or Canadian?

German or Canadian?

Ed, is your 75/1.4 lux German or Canadian?

I'm possibly on the verge of exposing a major theory, second only to the Kennedy one...

But I believe some of us are saying that it is possible to focus the 75 Summilux at f1.4 and f2.0 without a magnifier. Even with a magnifier, it is more than possible to use the 75 Summilux at f1.4 because that's the aperture at which I most often use it. Regardless, I'm happy with my experience with the 75 Summilux and the R-D1 whether you think it's real or just dumb luck.

 

[ampguy]

Much better Roland

Much better Roland

Showing the #'s is interesting - should the CL with 50/1 really be at ~ 132%, while the 75/1.4 on RD1 at 158%.

I haven't used the Noctilux on the CL, but had more of a hit/miss ratio with the CL and 40/2 @ f2, than the RD1s with 75/1.4 @ f1.4, but not sure it was EBL, might have been smaller VF patch on the CL.

Anyways I think it's a very interesting table you guys did, and I am just considering myself lucky being able to get good focusing in some of these borderline areas.

 

[MikeL]

Next meet up Ted, if you don't accurately focus the 75mm 90% of the time, the first round is on you. No drinking before the test either. We'll announce this before hand and we'll be guaranteed to have a good turn out. Free beer!

 

[edhohoho]

Ed, is your 75/1.4 lux German or Canadian?

I'm possibly on the verge of exposing a major theory, second only to the Kennedy one...

German, serial number beginning in the 39 range.

I think I may have caught a glimpse of your theory in another thread...