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A 20% brighter viewfinder for the RXII -
is that really the case, and is this noticeable with the naked eye, in normal light and lower light photography?
I'm thinking whether it is worth buying the II rather than the RX, and I'd appreciate the views of those who have used both cameras, or have tested them side by side.


Well-Known Member
this has been discussed here endlessly but i also would like to see a short statement. i think i would buy rx to profit from the distantmeter.


Hi I used to use an RTS2 and now use an RX, the differance in view finder brightness is noticeable but for me it is not a problem. To get an idea of the effect for you think of stoping down by 1/2 stop and the effect of this will be more than the effect of the 20% loss in view finder. I find the range finder far out weighs this for me as it lets me use a plane screen.
Hope this is of some help John.


>>A 20% brighter viewfinder for the RXII -
is that really the case, and is this noticeable with the naked eye, in normal light and lower light photography?<<

I'm sorry I can talk about these side by side since I only have the RX. But, if you need a bright and easy to focus viewfinder, then the RX is a terrific choice.

Kyocera has done a remarkable job of giving the RX the unique DFI feature while retaining an excellent viewfinder.

Maybe the RXII is brighter still, but IMHO the additional 20% is not needed.

Good Luck,


New Member
I have recently traded an RX for an RX11. I like the design layout of the RX and find the weight balance ideal with heavier Zeiss lenses, but have always thought the viewfinder lacked brightness (compared, for ex&le, to the Aria). The RX11 now has a brightness on par with the Aria. However it has inherited another characteristic of the Aria compared to the standard RX, which is louder shutter noise: the fabled smoothness of the RX shutter has been replaced by a coarser action which resonates more through the body. I do not find this a particular problem, but it is certainly noticeable. The loss of focus indication does not bother me, although the depth of field display was always a nice touch. Apart from brightness, another plus point of the RX11 is a two second self timer.

So like most things, it's a compromise: for me the brightness is the major plus point, but the shutter action may be a issue with those who love their RX for that very reason: if you happy with the RX as it is, it is probably best not to change.
I have not used the RXII, we in america are not fortunate enough to. But judging by the number, 20% seems significant at first, but on a second thought it really isn't. If we round up to 25% that is only 1/4 stop. I used my RX and stopped down from 2.8 to 3.0, which is 1/2 stop and noticed a VERY minute change, but it was noticeable. I am not certain that a 1/4 stop difference would be noticeable at all and I very much doubt it would be usefull.

I obtained a used/demo RX for $499 at BH complete with original warrenty, box, accessories and manual. While I know that finding a used or demo RX is mostly luck, and this was the only one listed at BH at the time, if you can find an used RX in 9-or-greater condition, and are willing to buy used, I am not certain that a less than 1/4-stop difference is worth the added $$.

I have read in another post that grey market RXII's in the US sell for $780. "Official" RXII's we can assume would cost some more, but still this is not an expensive camera by any means, but is $280+ worth a less than
1/4 increse in the viewfinder? Maybe for you it is.

If you are planning to buy new, I am not sure what features from the RX did not make it to the RXII. If the DFI is one of them, and this would explain a brighter screen from what I understand, I am not sure that $380 more for a new, old stock RX (based on Calumets price of $999) is worth the DFI, it does come in handy don't get me wrong, but it was a pretty big disapointment because I was expecting it to be more useful than it is. If you plan to shoot with a screen without microprisms or split screen, I think i'd use it all the time, well, when it works which is probobly only 65% of the time.

However, if the DFI is faster and more reliable in more situations on the RXII, and you control DOF religiously, I would suggest take gamble with a 380$ bet and give it a try, there are situations where it is useful. Like when you you are photographing something and don't have enough light for a small aperature but do have enough for a moderate and focussing somewhere in the middle to produce a sharp image. It's a nice secondary reference from DOF preview, which can be kind-of-hard to read in 35mm photography.

Either way, the RX/II seems to be a good alternative to the RTSIII if you don't need/want that much of a camera or cannot afford it. The ST seemed kind of pricey for as few added features over the RX, though, a 1/2-stop faster shutter might come in handy for those wide-open shots on sunny days. How many years have I used cameras without an illuminated counter? LOL, hardly worth teh differential.

The AX I just don't trust, WAY too much mechanics, and the Aria is too light.

But I am NOT a contax expert, even though i played one here, I have done extensive research on the models other than the G- and N-series. I have little first-hand experience and have been shooting contax for a whole, umm, two days now. :::blush:::

Either way, you can bet that this viewfinder won't be as bright as the Nikon FM's was which was by far the brightest I have ever used, obviously I prefer zeiss optics over the bright viewfinder of the FM and the average optics of Nikon.


Hi Shawn just to point out there is an error in your maths 1 stop is a reduction of 50% not 100% there for the loss of 20% is just less than 1/2 stop also for anybody interested I feel sure that replaceing the mirror with one for an RX2 would give you a brighter view finder image but disable the focusing assistance, not 100% sure of this but I am sure this so if anybody intends to do this check with contax first.


thanks everyone for your responses - has been extremely helpful, especially regarding the brightness of the viewfinder, but also re.the coarseness, and thus, loudness of the shutter - the last is an issue for me. I'll see if i can find and try out an RXII and see if i can notice the two said issues.
John- you are likely right, I have spent more time in the digital darkroom than out shooting. I am a digital media major that is about to switch to photography.

However, I could have sworn that 1 stop doubles the amount of light on the film. This is evident when you stop down and require a twice as long exposure.

If each stop down DOES cut the light in half, then each stop up DOUBLES the amount of light, right?

If this is correct, then:
f5.6=+0% differential (1:1)
f4.5=+50% differential (1.5:1)
f4.0=+100% differential (2:1, half as much total light)
f2.8=+200% differential (4:1)

Ratios are expressed as "light on film plane:light available"

If you take a value of 50 and increase it by 25% (more light) then the result is 62.5 ((50x0.25)+50) or calculated from ratio and simplified (50x1.25). If "62.5" expresses the luminance on the focussing screen this would not be 1/2 stop, a value of 75 would be (50x1.5) and a value of 100 (50x2) would be one stop as 1 stop expresses twice as much light entering the film plane.

As a value of 50 would already be present, the additional differentiated(sp) value would be added, resulting in the values 62.5 (12.5+50), 75 (25+50) and 100 (50+50).

In the case of a 25% or 1/4 stop increase (based on that 100%=2:1), would result in a +12.5 differential, as, 12.5 is 1/4 of 50 (50x0.25=12.5). A 25% increase could be expressed as 1.25:1.

So unless i'm TOTALLY off, which is entirely possible, 20% would be slightly less than 1/4 stop?
It will not let me edit all the sudden, but "half as much light" on the table above should be "twice as much light". I changed it around from stopping down to stopping up to fit the 20% increse scenario.
On another topic I do not understand how stopping down would work out. If a +100% differntial is twice the original value, wouldn't -100% differential be half?

Instead, it is zero, which is obviously not true! The ratios still stay clear, as one stop down would equal 0.5:1 or 50%.

This is not as easy as i thought it was.


Hi Shawn afraid your maths is a bit shakey 100% increase equates to doubleing to reduce by 100% is to reduce to zero, to halve is to to reduce by 50% and as we are talking about a loss not a gain I think you will find I am correct.
Hope this clarifies(my maths is better than my spelling) John.
though i am pretty sure that 1/5 stop is equal to 20% increase. You are right that my math is shakey on the differential portion, but none the less the ratios are correct.

Also, I just realized something. We *are* talking about I both increase *and* decrease because neither the RX or RXII take *precidence.*

Unless you are saying that if you look into the RXII first you get a 1/2 stop reduction (because we'd be reducing) and if you look into the RX first you get a 1/5 stop reduction (because we'd be increasing). Ofcourse this is silly! It does not matter which takes precidence because both reduce or increase at the same rate, 20%.


Posted by Shawn Kearney on Friday, July 18, 2003 - 8:47 am:

john- though i am pretty sure that 1/5 stop is equal to 20% increase. You are right that my math is shaky on the differential portion, but none the less the ratios are correct.



I think that any discussion about variations of 1/5 stop or any fractions of stops is imprecise, but probably reasonable for the discussion in this thread.

The fact is, as we all know, that the light collected is inversely proportional to the square of the F-Number.

What we don't know is just how far one would move the F-Stop indicator to cause a 1/5 stop change. There is no reason to expect that the change is F-stop is linear with position. The only thing we know for sure is that, with reasonable manufacturing care, the F-stop settings marked on the lens are probably close, but in-between settings are just guesses.

On the other hand, since this thread is dealing with pretty small numbers, I wouldn't ague very strongly that moving an F-Stop indicator 1/5 of the way between two indicated F-numbers is a reasonable approximation of an actual effective change of 1/5 stop.



Hi again Shawn what I am saying is that the mirror in the RX only reflects slightly less than 80% of the incidental light falling on it which equates to stoping down the lens by slightly less than 1/2 stop. this effect is visable. if it equated to 1/5 stop it would be almost unnoticipal. This does not bother me for the reasons in my other post to this thread If you order from B&H now you will find a tax bill for approx £72 will land on your door step in about 3 weeks, still a great deal(thats what I did) and if the view finder bothered you I am sure that a compitant repair man could change the mirror for one for an RX2.
Hope this reply dose not sound to pedantic by for now John
P.S if you want to talk about my likes and dislikes of the RX against my old RTS2 my email address is
To settle this once and for all, I wrote kyocera and got the following response. It turns out I am right, but not at all for the reasons which i thought I was. The real reason why 20%=a little MORE than 1/4 stop is WAY above my head:


Thank you for your e-mail.  You brought me back to photo school.  I knew when I saw the press release on the RX II that this was going to be a bit of a problem.

The answer lies in logs.

Numerically, if the writer means that the RX transmitted 100 units of light, now the RX II transmits 120 units, we have a 20% increase in the number of units. 

We begin with a log value of 2.0 representing 100 units of light and add 20 units for a total of 120 units of light.  The log value of 120 is 2.079.  The difference of one full stop in log luminance is .3.  We have an increase in log value of .079 divided by .3 = 26%.  I have to make a leap here and say that 26% of .3 = a tiny bit more than 1/4 f/stop.

It is never a good idea to mix logs with percentages. 

Blake Ziegler
Contax Technical Director

You can visualize 1/5 stop by stopping down to 1/2 stop, and compairing the previews. Then you can guestimate 1/2 of 1/2 stop, 1/4 stop, and figure it is indistiguishably close to 1/5. It is not perfect, but for all intensive purposes, it works. Especially since 1/5 stop is likely not even visible.

I think after my reply from kyocera, there is little doubt that the difference betwene the RX and the RXII's viewfinders is muniscle(sp).


New Member
>I don't discount the discussion on this for a moment, but may I risk being >subjective here amidst the mathematics? The RX11 now has, for me, that >focusing 'snap' (see previous threads) that is so noticeable in the Aria >(and indeed, from memory, the RTS 11). This may not amount to much when we >crunch the numbers, but it has that extra edge that makes all the >difference in practice. If the RX already satisfies users on this count >(and from the correspondence it clearly does), then there is little to be >gained in changing.
andrew- obviously your post is more useful than mine, this is why I disclaimed I had never used the RXII.

I think at this point the discussion is about "what is an f-stop" than "RX v. RXII"