Help me educate myself

[Little Prince]

I have been contemplating a real rangefinder. My needs are not great. My wants are. Unfortunately I have little knowledge of rangefinders and have looked at a lot of gear through useful and informative websites. Some questions have been repeatedly popping up. Please help me find an authoritative source of information on these topics:

1. What is a rangefinder's baselength and of what significance is it in focusing? I understand vaguely that the more the better but beyond that not much clue.

2. How the VFs of rangefinders deal with framelines for different focal lengths and the effect of this on VF magnification.

Ok, those are the two important theoretical questions for now. I have a decent amount of background with SLRs but coming from that angle, some aspects of RFs are unknown to me. The nearest camera I have to a rangefinder is a (Fuji) GA645, which is really a point-n-shoot (with scale focusing ability). Even this was acquired only recently. Thanks.

 

[Doug]

Hi Prince... ManGo has given good info. Additionally, for your #1 question, take a look at the sixth post in this thread: http://www.rangefinderforum.com/forums/showthread.php?t=227

For #2, the framelines are provided by a switchable mask behind the middle window on the front of the RF camera body, which is adjacent to the big main viewfinder window and about the same size. As the frame selector switch (automatic on Leica M, Minolta CLE, Hexar RF, and the new Zeiss Ikon, manually done on Bessas) moves according the the lens mounted, different masks move to show the appropriate framelines.

You'll note that most fixed-lens RF cameras don't have that third window to illuminate the masks, because their fixed framelines are built right into the main viewfinder optics. As a separate issue, generally these cameras' RF focusing spot is not sharply defined, and appears as a fuzzy spot in the center, and usually tinted yellow.

 

[Little Prince]

You are clearing a few things up. But there's more to go 🙂 .

Regarding baselength. I have seen it mentioned that if you have a certain baselength, say 40mm, then you can accurately focus some set of lenses but not a 75/1.4 for example. It appears that the longer and faster lenses require more baselength. My guess is that the ratio f/f-number (=aperture) determines this. Am I right? Is there a simple number to compare the baselength with? For instance, it would be very convenient if having a baselength of 50mm meant I could use a 50/1 (=50) but not a 75/1.4 (=53 or so). Is any of this true or is it idle speculation on my part?

The thing I need to know about finder magnification is this:
If a have two cameras, both with same total finder magnification and one with framelines for 28mm (or longer) and the other with framelines for 40mm (or longer), then the size of the 75mm frameline in the finder (by which I refer to the effective magnification for the 75mm lens) must be smaller on the first camera as compared to the second one. Is this correct? I ask because I am naturally concerned about the size of the image in the finder. If I chose a camera with framelines for a wider lens than another, all other things remaining constant, the VF image when I use a longer lens is going to be smaller right?

Hope I don't sound too muddled. If I get these things right, I'll move on to the specific cameras I am considering 😀 .

 

[aizan]

see this:

http://www.imx.nl/photosite/leica/technics/rfaccuracy.html

the second table says what baselength you need for a certain focal length and aperture.

if the viewfinders are of differing magnifications, the framelines will appear to be different sizes. the newer .72x leica viewfinders have 28mm framelines, but they are so magnified that they're on the extreme edges of the viewfinder. a lower magnification viewfinder of .58x was made to remedy this. going the other direction, a .85x or 1:1 viewfinder will not have 28mm framelines, but it will have the biggest 75mm framelines.

 

[Little Prince]

I believe I am understanding better now. When we discuss specific cameras and lenses, the remaining issues can be thrashed out. Thanks to all.

 

[Doug]

Aizan is right, and I'll just add, for the magnification and framelines issue, that a particular frame's size as seen by the viewer depends only on the magnification... and incidentally also on the "fudge factor" built in by the designers. As with typical SLR viewfinders showing only some 90% of what will appear on the negs, RF viewfinder frames do the same to one degree or another. For instance, from what I've read, there's more "fudge factor" in Leica framelines in the M6 than the M2/M3. So presumably the M6's 50mm framelines might be a tad bit smaller than the M2's, both using 0.72x viewfinders.

This is also affected, in shooting, by the actual focal length of the lens. You'll obviously get a bit more on film from a "50"mm lens that's actually 50mm than from one that's really 53mm.

 

[Roger Hicks]

Shameless self-promotion: take a look at the book RANGEFINDER by Roger Hicks and Frances Schultz, published by GMC. There's further infornation on our web-site, www.rogerandfrances.com, "Our Books".

Cheers,

Roger

 

[Huck Finn]

Little Prince, great information has been posted here. I'll just add one point. The size of both the camera's viewfinder & the eyepiece through which you view are also a factor in how much of the frame lines you can see. This is the big deal about the new Zeiss Ikon. It has a large viewfinder coupled with the largest eyepiece I have seen. This allows them to have a long 75 mm base line combined with a relatively high .74 magnification & still have room for 28 mm frame lines which can be seen fully without much effort.

Another good treatment of this subject is Stephen Gandy's article, "Rangefiner/Viewfiners:
more than meets the eye" in his section entitled: "Classic Camer Profiles" on his website www.cameraquest.com.

Huck

 

[Little Prince]

Thanks everyone. I'm not really looking to use very long lenses or superfast ones, so I guess it's between how wide I can go (without an auxiliary finder) and how big an image I can get in the viewfinder. Always good to simplify things.

Roger, for a while there I had forgotten about the existence of books! I went to the bookstore today to look for your book. They didn't have it there but said they would get it in a few days. At times like these I regret the damage online trading has done to store fronts. It's not bad with books (it doesn't take much for me to decide to buy a book, they are seldom so bad that you regret it). For other things however it's so much easier if I could just look at it (and hold it). Anyway I'm digressing.

 

[Roger Hicks]

Dear Little Prince,

(Now THERE is a greeting!)

You think YOU regret the damage online trading has done...

This is why I decided not to have an Amazon.com link from my web site.

Where in India are you from? Should I address you as Chhota Raj'? (by analogy with chhota peg and burra peg)

Widest without auxiliary finder: 28mm with modern Leicas. Big image: choose your viewfinder magnification.

Cheers,

Roger

 

[Little Prince]

From a little town called Mysore deep in the south. Was there till I was about 18. Then moved to another place in India when I started going to college. Finally moved to the US and still studying.

I'd also better mention that I'm not practising any sort of anti-online thing at all and buy from internet stores frequently enough. Mostly because it just doesn't occur to me to do otherwise. But sometimes (like when I wanted to try out some camera) I've been unable to enjoy the simple convenience of seeing what I want to buy and this bugs me. Maybe in the future, for some particular commodities I will make it a point to buy from a local store even if I have to pay a little more.

And about the Little Prince thing (amazing greeting I agree), I ought to just sign my name at the end of my posts so people don't think I am 10 years old 🙂 . So here goes...

Anand

 

[Roger Hicks]

Dear Anand,

Not so small! My wife and I have only been to Mysore once (during a 4000km tour of South India -- on a Bullet, of course) but we were very taken with it. My wife and I very much hope to get back as soon as we can.

There are a couple of pictures of the Maharajah's Palace on my web-site: go to 'Buildings and Interiors -- India'.

Where for college?

Cheers,

Roger (www.rogerandfrances.com°

 

[Little Prince]

Dear Roger,

Sorry about the slow response. It's just before bedtime that I usually inhabit the forums (or is it fora?). Brings me a smile to hear that you have been through my home town (so to speak). I followed some of what you have on your website about your travels. Very interesting. Saw those photos too. The palace is naturally an object of tourist attention but locals rarely bother about it. I guess it's the same everyhwere. But having been away from home for a few years I was particularly gladdened to see those pictures of arbitrary points on the road. These things (like wilderness areas and the natural vegetation, etc) lend me a sense of connection that I do not feel when I see pictures of towns back home. By the way, I went to Madras (now called Chennai) for undergraduate studies. A swelteringly hot and humid place.

 

[Roger Hicks]

Dear Anand,

I know what you mean about tourist sights/sites. I have lived in many 'tourist' areas -- I am a Cornishman and I've lived in Malta, south-east England, Scotland, Bermuda, California and currently the Loire Valley -- and the locals never bother with the tourist attractions. It wasn't until 30 years after I left Malta that I saw some of them on a return visit. It's the everyday stuff that reminds you of 'home' (for a given value of home...)

Of course I was in Madras to pick up the Bullet from the factory. That was quite fun: twilight, rush hour, and left brake/right gearshift instead of the right brake/left gearshift on the BMWs I normally ride...

Glad you liked the road pics. I love touring in rural India! God willing there may be some more next year.

Cheers,

Roger