Considering the HY6

[DeckardTrinity]

+1 on the congrats - you will love the system! I unfortunately have not had the time the past half year or so to get my system out, but decided to check in here to see what the latest was. Really, really glad to see we have an official U.S. dealer now for Hy6 / Rollei gear!

 

[EH21]

Hi Geoff ,

The lens offset adjustment (auto save the offset value)also appliable to the older AF (not AFD) ??

Hi,
I just tested this, and yes the Mod2 does remember the AF offset value for my AF 50 f/2.8 as well as the AFD 50.
Regards,
Eric

 

[EH21]

Eric,

I want to ask a question but you may find embrassing , do you tested that the image(optic) quality of manual focusing 50mm F2.8 PQS is same as AFD's ?

The older manual only focus 50mm f/2.8 is different optically than the AF and AFD 50mm f/2.8 and in fact it also weighs almost twice as much as the newer ones.

My impression is that the newer lenses are sharper, but have a bit more distortion. The distortion is easily correctible as its a simple curve. I have Imatest values for only the AF 50/2.8 as this is the only one I currently own.

 

[Rollei6008i]

Many thanks to your serious reply .

 

[Rollei6008i]

I walk around the 2nd shop in HK & I just find the MF 50 2.8 , it really heavier as you are saying, I finially bought a new AFD .

Many thanks indeed .

 

[Rollei6008i]

Hi Eric,

I want to know the new Roolei lens - 35mm Flektagon lens PQS , when will it be on production & any prototype made for our vision ?

 

[ondebanks]

in my testing with the 80mp AFi-ii back some of the lenses are hitting the theoretical limits - .5 cy/px at MTF 50.

Eric,

It's brilliant that you are systematically testing all these lenses and that you are intending to publish your extensive results.

I just want to correct a possibly misleading conclusion in the above statement: ".5 cy/px at MTF 50" is very impressive for that setup, but it is not the "theoretical limit" of the lens. It is a useful practical limit for that particular system (sensor + optics), but a higher MTF 50 at 0.5 cy/px is both theoretically attainable by the optics and desirable [assuming effective software solutions exist to deal with the inevitable aliasing of details above the Nyquist frequency, when there is no AA filter].

In particular, your result gives no guarantees or expectations -
(a) that the lens would hit the same MTF at the Nyquist frequency with smaller pixels,
(b) that the lens is hitting its true performance limit (diffraction limit), or
(c) that it would deliver diffraction limited performance at many or all of its aperture stops.

Ray

 

[EH21]

Eric,

It's brilliant that you are systematically testing all these lenses and that you are intending to publish your extensive results.

I just want to correct a possibly misleading conclusion in the above statement: ".5 cy/px at MTF 50" is very impressive for that setup, but it is not the "theoretical limit" of the lens. It is a useful practical limit for that particular system (sensor + optics), but a higher MTF 50 at 0.5 cy/px is both theoretically attainable by the optics and desirable [assuming effective software solutions exist to deal with the inevitable aliasing of details above the Nyquist frequency, when there is no AA filter].

In particular, your result gives no guarantees or expectations -
(a) that the lens would hit the same MTF at the Nyquist frequency with smaller pixels,
(b) that the lens is hitting its true performance limit (diffraction limit), or
(c) that it would deliver diffraction limited performance at many or all of its aperture stops.

Ray

Hi Ray,
Thanks for the input. On some of the tests, the values were actually over .5 but I assumed that I had done something wrong such as overdone the capture level sharpening. I think I came to the conclusion that 1 pixel could only represent 1/2 a line pair at best, so assumed .5 was the max possible. But I haven't had enough time to really dig into this which is also a reason why I haven't published anything so far since I want to make sure it's done really as best as I can. I got some guidance from Norman Korren on capturing the test files and made a test chart 8feet wide to accommodate the higher resolution backs. And your right about the pixel size as well. Norman likes to use lp per picture height as well as cy/px for that reason I guess.

Couple other potential pitfalls to my testing: 1)Focus distance: The chart is fixed and I try to fill the frame - so this gives only one focus distance - about 2-10 meters focusing distance through the range of lenses. 2) Sample size: I have only tested one or two copies of each lens in most cases second hand. 3) actual focusing on the test charts - this has proven to be quite a challenge in practice especially for the wide open tests. The apex of the focus is apparent - very slight changes in chart to camera distance (1mm) can affect the results.


Imatest doesn't generate MTF style charts as many people are familiar with. How do you suggest I present the information?

Thanks,
Eric

 

[Rollei6008i]

I have a question about the ' Focus sensor setting " in Hy6 mod2 , -- Full , Medium & small , according to the manual, it is 70px , 50px & 30 px respectively. But, is there any indications which area(s) that I pointed to for the focusing reference points ? ( or , only in the middle of the focusing screen).

Will Hy6mod2 producing a better contrast screen such like Hasselblad's eariler optical fiber screen(which heard about that is produced by oem minolta) ? It really helpful for better manual focusing.

 

[jerryreed]

these backs are hard to come by preowned. I also worry about support since the Hy6 is discontinued

As owner of the SINAR Hy6 and the Rolleiflex Hy6 mod 2, please accept my assurance that the Hy6 is still sold and supported.

Jerry

 

[EH21]

I have a question about the ' Focus sensor setting " in Hy6 mod2 , -- Full , Medium & small , according to the manual, it is 70px , 50px & 30 px respectively. But, is there any indications which area(s) that I pointed to for the focusing reference points ? ( or , only in the middle of the focusing screen).

Will Hy6mod2 producing a better contrast screen such like Hasselblad's eariler optical fiber screen(which heard about that is produced by oem minolta) ? It really helpful for better manual focusing.

Hi,
Regarding the screens. The Hasselblad acute matte screen was a design from Minolta where they used hexagonal cells sandwiched together. This meant no dead space and more transmitted light. There wasn't more contrast though it was brighter. I've tested some of these Minolta patent screens as they are sometimes referred to in my focus tests and think the High D screen now or the Bill Maxwell screens yield more accurate focusing. I found with the acute matte screens that you'd think you were in focus and then you'd move the knob and not be sure - it didn't just pop in to focus at one spot. I know these are 'legendary' in the Hasselblad lore, but I found them to not live up to the expectations other than brightness. Maxwell screens and High D screens were the only two screens at the top. Actually the ground glass screens have the most contrast of them all, but are not as bright and are dark in the corners. I've been meaning to experiment with a fresnel over the ground glass screens and have asked Steve Hopf to grind me a very thin borosilicate screen such that both the fresnel and screen could fit.

Overall the matte screens are better than the split prism screens for manual focusing.

I find that using the lupe finder the best for manual focusing, followed by the 45 degree prism.

Focus spot size setting in the options menu affects the size of the active area, not the location on the screen. I usually keep mine set to small.

 

[Rollei6008i]

Eric,

Thank you that you are always replied in details , simply speaking, the focus sensor set to small is more precisely ? The focus reference area is in the middle of the screen ?

 

[Geoff]

Yes its in the center. Don't know about more precisely, but small works well.

 

[EH21]

Regarding the focus spot size question: I have only experimented with this, not been provided any special information from the factory, though I will ask next time I have a chance. My experience is that the size makes a difference in how the AF works. For example if you set focus spot to small you can focus on the persons eyes, but if you set it to large it may focus on the outline of the head. It seems like the larger spot setting is better for low light or landscape kinds of shooting, but there are some times when it makes sense to use it for portraits. Here's one - shooting portraits of people with glasses. You try to focus on the eyes, but get the face of the glasses. Using the larger spot size catches the outline of the head which works out to be in the plane of the eyes. That's my experience anyhow.

I will have to ask the DWH engineers what they recommend and when one setting is preferred over another or if there any advantages such as faster focus speed with the larger spot. But in the mean time, I encourage you to try it out.

 

[MarkoRepse]

Interesting you mention this Eric, it seems consistent with my findings. I also find if trying to focus on very thin subjects like wires it likes to back focus. I'm using the small size all the time now but may have to revisit larger sizes since you mentioned they may be better for low light.
I actually have an email from DHW where I asked what the 30/50/70 pixel measurements represent and what AF locks on to with this response:

"30/50/70 pixels is a linear area.
full scale is the ring on the screen.
Normaly the AF use the nearest object, but if the nearest object is out of 30 or 50 pixels than
The AF thy to find a better target."

Again this seems consistent with actual behavior.

I find that using the lupe finder the best for manual focusing, followed by the 45 degree prism.

Here by lupe you mean the actual loupe and not WLF? That would imply the 45 prism is better than the WLF, which is interesting.

 

[Rollei6008i]

This is an interest tropic , I found that when I use small for taking lanscape , the in focus display > F< is diffcult to appear , I need to set at full or medium for landscape in order to obtain > F < .

That is why I ask this question for better focusing action.

 

[EH21]

Here by lupe you mean the actual loupe and not WLF? That would imply the 45 prism is better than the WLF, which is interesting.

There are a lot of variables here, so what works for me may not for others, but in general I find the lupe finder the most accurate for me and next the 45 degree prism finder. I do use the WLF, but mostly when I want to travel light or compact. I find the WLF hard to use without my glasses which I hate to wear - others with good vision may like it better. I know many people who prefer the WLF or the 90 deg finder, so this goes as much to personal vision and preference than anything. The lupe finder is adjustable for diopter correction and has a 3x magnification and a very larger viewfinder.

In general I like the shooting position of the 45 degree finder as well as camera position. The 45 prism gives you a non-reversed image too which is nice. The lupe is very close to the 45 in terms of camera position and also is lighter weight. Quite honestly the lupe base for the Hy6 is very expensive, but I do think its worth it.

The great thing is that DHW offers so many finder options for the camera.

Also worth noting - I've adapted the dioptrx (astigmatic correction) to fit the Hy6 and 6008AF 45 degree prisms and this also fits the lupe too.

 

[Rollei6008i]

For me, I have both 45 & 90 degree finder as well WLF , I always use 45 finder as it is better holding camera & not lateral inverse the image when shooting active subject .

When in a few occasions , 90 finder give me eye level where are more easily viewing thru .

 

[MarkoRepse]

I got a 45 prism recently, interestingly enough I find it the most difficult to focus! I can see your point, however, if you require additional corrections. The problem it seems is the size, it is clearly the least magnified of all. The view is nice though, a proper prism, but I find I still prefer the 90, despite it being somewhat difficult to view through being very susceptible to viewing angle. The size (and personally I prefer the positioning) makes up for it. Of these three the I find the WLF best for focusing, and the 90 isn't that far behind actually. I'd really like a 90 *prism* finder the size of the current one! If anyone is interested I'll be selling the 45.

 

[mmbma]

I like the WLF, and I got a 90 dgree from a deal that I couldn't pass on.