New CV cameras and 40mm/1.4 lens!

John, a 1x finder would be very nice.

Konica Hexar RF also includes 28 mm framelines in its finder. I understand that the Bessa finder approximates 28mm, so that too can be used without an auxiliary finder - although the auxiliary finder has to be much easier to use.
 
Huck Finn said:
Pherdinand, you have a good point & I may have been too hasty in responding. Wider lenses are more compact than standard lenses, so the 40 mm length should help make it more compact than a 50 to begin with. I was reacting to the definition of compact in the post: "as compact as the 35/2.5 pancake II."

That Voigtlander lens is only 23 mm long!

Let's look at the length of some Leica lenses:

35/2 = 34.5 mm
35/1.4 = 46.2 mm

50/2.8 = 37.6 mm extended/21.6 mm collapsed (storage position)
50/2 = 43.5 mm
50/1.4 = 52.5 mm

To make a 1.4 lens of longer focal length (40 mm) as compact as an already compact 2.5 lens (1.6 stops slower) of shorter focal length (35 mm) would be a miracle IMHO.

To build a lens just one stop faster (1.4 vs 2), Leica had to increase the length about 20 - 25% on both the 35 & the 50 - with the greater increase on the wider angle lens, which is the one closer in focal length to the rumored 40.

If Cosina could build a 40/1.4 at the same length as the 35/2. I think that would be remarkable. But as you point out, this would still be quite compact.

Cosina has accomplished miracles before, so I'm prepared to be duly impressed. However, until I actually read some facts, you'll have to consider me to be a doubter on this rumor.:(
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I have to admit that I am duly impressed! They were able to make this lens even more compact than I thought they would be able to.

However, it is not as compact as the 35/2.5 P II - although it is built in the same style. At 29.7mm in length, it is about 30% longer than 35/2.5P II - which is to be expected given the longer focal length & faster speed, but not what was advertised. To give a frame of reference with another 40mm lens, here is a side-by-side comparison of it & the Rollei 40/2.8.

CV 40/1.4 = 29.7mm/43mm filter/55mm wide
Rollei 40/2.8 = 30.5/39mmfilter/56 mm wide

So. looking at the two 40 mm lenses, the new CV 40/1.4 would not appear to be the ultimate in a compact lens. Both are about 30mm long & about the same width at the widest point, but the Rollei 40/2.8 tapers to a 39 mm filter size while the CV 40/1.4 is about 10%wider. I should note as well that Rollei has a permanently positioned built-in lens hood included in its length, while the extra lens hood for the CV will add length & width.

What is miraculous is that Cosina could build a lens that approximates the size of another of the same focal length, but the CV is 2 stops faster! And it is far more compact than any lens of comparable apeed.
 
Interesting indeed. I wonder how it compares to other 40s? I haven't seen the dimensions of the f2 Leica C or Minolta Rokkor CLE, but they are both very compact, and that is only 1 stop slower than the new CV 40. Perhaps there is something to the 40mm focal length, closeness to "normal," that allows optical engineers to design more compact lenses?
 
Darn I've got the idea of selling my 35/2.5 and 50/1.5 to get this 40/1.4 :bang:

Two lenses, 40/1.4 and 75/2.5 with the same filter diameter 43mm sounds really good. Bessa R2 35mm framelines gives 100% coverage of 40mm also sounds good. Must not give in to this tempation...must...not...give...in....ARRGGHHHHHH
 
WHEN (not if) you give into your temptations :D Send me an e-mail with a price on the 50/1.5.
 
This is a dangerous place to hang around!

Alright, I will only sell the Nokton IF the buyer takes the Pancake II as well. I will not letting them go until the new 40/1.4 is available on the market though.
 
Kris said:
Darn I've got the idea of selling my 35/2.5 and 50/1.5 to get this 40/1.4 :bang:

Two lenses, 40/1.4 and 75/2.5 with the same filter diameter 43mm sounds really good. Bessa R2 35mm framelines gives 100% coverage of 40mm also sounds good. Must not give in to this tempation...must...not...give...in....ARRGGHHHHHH
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Hi Kris,

You mean that I could use the 35mm frameline of the R2 if I get the 40m/1.4?
 
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Peter said:
Hi Kris,

You mean that I could use the 35mm frameline of the R2 if I get the 40m/1.4?
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After reading your question I did a quick test using bathroom wall tiles. I don't have 35mm on SLR so I did the test with 50mm instead.

At 1.5m, the coverage of Bessa R2 50mm framelines matches almost perfectly with my EOS viewfinder, 97% horizontal & vertical. At 1m, probably the 50mm framelines to cover 100% of film frame.

I read somewhere quite long ago the framelines on R2 cover 87% of film frame. I'm pretty sure that's at infinity. Now the question is: 87% area or 87% horizontal & vertical? If it is 87% are, that means 93% horizontal & vertical, which is pretty tight.

As far as I know, angle of view and focal length are inversely proportional so 40mm angle of view is 87.5% of 35mm angle of view.

If R2 framelines are covering 87% horizontal & vertical of film frame, then at infinity, 35mm framelines give you 100% of 40mm angle of view. But I suspect that 87% is the area covered i.e. 93% horizontal and vertical. You need to buy BOTH 40/1.4 and Bessa R3A. What excuses are you going to say to your Boss? Hehehehe.
 
Peter, Cosina states that it's framelines cover 87% of the field of viewe. Since 40mm is a narrower field of view than 35mm, the 35mm framelines should be close to 100% coverage for the 40mm field of view. So, I would think that with a little practice, the 35mm framelines should be quite usable for the 40mm lens.

Of course, there is a reason why they only cover 87%. It's to provide some margin for error since rangefinder framing is never as precise as an SLR. So, you'll be fine as long as yo don't mind running the risk of occasionally lopping someone's head off. :D :eek:

EDIT: I had not noticed Kris's post when I wrote mine. Sorry to be repetitious of some of his information.

BTW, you can always buy the separate 40mm viewfinder - cheaper than a second body & easier to sneak by The Boss. :angel:
 
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I read somewhere quite long ago the framelines on R2 cover 87% of film frame. I'm pretty sure that's at infinity. [/B]
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I double checked this info on Gandy's site - 87% coverage at 3 meters (10 feet).
 
"As far as I know, angle of view and focal length are inversely proportional so 40mm angle of view is 87.5% of 35mm angle of view." - Kris, not EXACTLY - in fact, the tangent of the angle of view is equal to the ratio l/f, where l is the width, height or diameter of the negative and f is the focal length. This in ideal case, of course (infinity focussed). This will give:
- 45.8 degrees horizontal / 34.4 degrees vertical / 51 degrees diagonal angle of view for the 35mm lens
-42 , 31, resp. 47.2 degrees for the 40mm
which will mean that the 40mm's angle of iew is a percentage of the 35mm like:
-91.7% horizontal, 89.3% vertical, and 92.5% diagonal. These are all slightly more than the 87.5% you obtained...
 
Ooops! Sorry for all my misleading informations. Never ever post anything without cross referencing in the future! :D

Back to read all these photo related books.

PS: Huck Finn, that 87% at 3m is area coverage, right otherwise there is too much area in the film not included inside the framelines?
 
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As an addition: if you focus closer than infinity, the formula becomes: angle-of-view = arctan [l*(d-f)/(d*f)] where l is the width/height/diam. of frame, d is the distance where you focus to, and f is the focal length. This gives, as example, for the 35mm lens focused at 3 meters, a horizontal angle of view of 45.47 degrees - which is quite close to the infinity angle of 45.8 degrees. At 1 meter this becomes 44.8 degrees - one single degree less than the infinity case.
Moral: for the FOV does not really matter where you focus your lens unless you go macro.
 
Don't worry - i don't think many important stuff will be left off the frame due to the 2-3 degrees error in your calculus! :)
 
Wooo, that's a lot of math.

Peter, I use my 40/2 CLE with the 35mm frame lines of my R2. To date I have not cut off anyone's head or missed my target, so I would say it works really well.
 
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