Robert White investigated my RD1s focus accuracy

[wintoid]

I sent my RD1s back to Robert White to look at the focus accuracy. I've had it for some months and had a lot of fun with it, but have never felt it was focusing as precisely as my R2a. I don't really like to do tests, but after having this nagging feeling for several months I decided to test it using my Nokton 40mm lens, and did find a problem (or so I thought). I put my results here http://www.codesound.com/rd1s.html and sent Robert White the link to the results.

Several weeks have passed and I have heard back as follows:

Yesterday we had a visit from An Epson engineer to help us deal with enquiries regarding the RD1 and RD1s and I took the opportunity to have your camera examined. Your camera is according to testing absolutely accurate from a focusing point of view, the problem will be with the lens you are using. Epson base the focusing standard on using the Voigtlander 35/2.5 Skopar and an inch scale at 45deg to the camera. 1.5 inches either side of the target is allowed to show full sharpness. Attached is a picture I took using this method using your camera and the 35/2.5, focusing on the fig 6 wide open at minimum focus distance. You can see that the 6 is sharp and that 5 and 7 are evenly soft.. in fact there is no forward or back focus at all...it is spot on.

One of the problems with focusing is the sheer number of different optics that people are using with their RD cameras.. from vintage M lenses, Russian stuff, Voigtlander, and the latest Leica 6 Bit. The biggest problem is backlash in the lenses.. this will lead to back and front focus on occasion. Historically this has always been an issue with rangefinder cameras. Users normally blamed the cameras and had for example Leica, adjust the bodies... all this actually does is set the camera up for that lens ...there is no guarantee that the next lens will produce sharp pictures as a result of such an adjustment. This is why Epson settled on the 35/2.5.. they have to have a standard. It is true that there will be a certain amount of back lash in the RF system but this is accounted for in the RF design.

The wedding of 80 year old focusing technology with 21st century capture has made users much more aware of what is involved with image quality. It now only takes a couple of key strokes to look at a 100% crop from a frame to determine the performance of a lens. When we were shooting film this was much more difficult and time consuming...but the problem would have been the same...often in fact worse, as there is the question of film flatness, or rather lack of it, to take into account.

So back to square one for me. RW's test with the 35mm f2.5 looked perfect, and was far more exacting than the test I ran myself. I've never put the Nokton on the R2a, so it is possible that it's simply a lens problem. I can now either test the camera again with a different lens (which I don't really want to do), or accept that I'll need to avoid wide apertures at close distances (which I don't really want to do).

I thought I'd post this as I'm sure some people are interested, and in particular because of the information about using the 35mm f2.5 as a benchmark. I guess that makes that lens a good choice for the RD1s

 

[ZorkiKat]

There is truth in what Robert White said. In the past, we've based our lenses' performance on what we see on print- often on postcards or sometimes as large 10 diameter prints. In all of these cases, we don't get to see the details magnified to the same degree as what two clicks on the keyboard can do to an image on the pc screen. Perhaps we have been looking at the way our lenses focus too critically when we 'sniff' their details onscreen.

Jay

 

[Terao]

Agreed, pixel-peeping must frustrate camera/lens manufacturers as much as the obsession with megapixels (consumer market) and high ISO noise (prosumer) market does.
Photos just aren't designed to be looked at at 100% close up on a monitor, they're desinged to be printed and/or stuck on a wall and observed from a distance...

This is something I'm learning at the moment, took a load of shots at my work's Christmas Party this week that I hated on screen (soft, lots of noise) but everyone who has seen them really likes. Got a call from my brother yesterday who loves a shot I took of him at a wedding a couple of weeks ago that is seriously out of focus and technically imperfect. Technique has its place of course, but photography I think should be more about emotion...

 

[Jim Watts]

Wintoid,
The only problem with Epson using the 35mm f2.5 as a bench mark (or any specific lens) is the tolerances within that sample of the lens when matched to a particular body.

"at 45deg to the camera. 1.5 inches either side of the target is allowed to show full sharpness". I'm trying not to be too pedantic, but really you should have approx twice the distance sharp behind the focussed point to that in front if correct focus has been achieved.

I have just this week picked up a (mint) secondhand 40mm Nokton. GAS attack plus the extra stop over my 35mm Cron and the fact that my Cron has always front focussed slightly on my R-D1. I was a bit wary given the limited depth of field at f1.4 that I might experience worst problems with repeatability of focus (due to the R-D1 rangefinder base length & backlash) or front or back focus problems on the R-D1.

So I ran some tests and unlike my Cron or your sample of the 40mm Nokton mine seems pretty much perfect. Good repeatabity and accuracy of focus wide open at 1 (approx 0.5" in front and 1" behind @ f1.4) & 2 meters, so I will be quite happy to use my sample wide open and fairly closeup in preference to my Cron. Sorry you have not got such a good match.

Jim

 

[Trius]

Yet another benefit of fixed lens RFs!

Seriously, in another thread here about setting up an M, DAG had calibrated to a DR Summicron, and other lenses then appeared to have a problem. The DR had to be shimmed as it was "out" 9/1000, IIRC.

 

[Didier]

The answer of RW is partially true, lenses may vary in coupling accuracy. But it was just the Color Skopar 35/2.5 PII, that I owned two years ago, which had the biggest off-front focusing tolerance of all my lenses.

But if all your lenses focus weirdly on the R-D1 but acceptably good on a M6, it might be a R-D1 issue, too. Because another problem with the R-D1 rangefinder is that a small knock can disalign it easily. So even if it's adjusted well, it may get out after a short time. And this has nothing to do with lenses.

Btw my R-D1 was inspected by the Epson engineer, yesterday too, and he admitted the sensor is tilted, but could not offer an instant solution. RW promised me to forward Epson's response in the next days.

Didier

 

[wintoid]

At the moment I don't really know what to think. I pixel-peeped the RD1s because I have felt over the last 3 months that something wasn't right. I've only pixel-peeped it with the 40 Nokton. I've never felt that way with the R2a. I don't think my analysis is affected by the fact that one is digital and one is film, as I'm a negative+scanner guy and not a wet printer.

If they send the camera straight back to me with no alteration, I'll probably repeat my test with a different lens. For all I know, the problem could even be my eyesight!

 

[mountainrivera]

Good luck Didier. I see a new camera in your future. A tilted sensor is their fault even if the camera is out of warranty. Giving you a new body is the right thing to do.

 

[Didier]

At the moment I don't really know what to think.

Same for me. If I get a new R-D1 from Epson which has a straight sensor but the same alignment problems again, I will have to rethink about digital rangefinder photography.

Considering all the troubles the M8 & R-D1 are actually causing, I'm thinking loud about switching over to DSLR. Keep the canon VT, bessa L and some old lenses for the rare film fun shootings, sell M6, R-D1, Summiluxes and all the rest, and getting a well stuffed DSLR camera bag including a D200 or a 5D.

Finally, I want to make pictures without thinking too much about the gear. Just take pictures.

Didier

 

[jlw]

Being in the USA, I'm a bit envious that you have a place you can take your R-D 1 and they can have an Epson engineer examine it and then will report back to you with the results!

I do think there's a great deal of validity in what they say -- especially the part about how lenses that always seemed acceptable to us when we were using them on film RFs now seem more problematic when we try them on a DRF, simply because it's now easier to make critical comparisons.

I've always known that even with modern qualilty-control methods there's more sample-to-sample variation in lenses than photographers feel comfortable acknowledging -- but I guess I had never thought of it before in this particular context.

One thought: Since it's undesirable to adjust the camera body to match a specific lens (since that might throw the next lens even farther off in a different direction) how about adjusting your lens to give optimum results with your specific R-D 1s body?

I don't know how difficult that might be on the 40/1.4 Nokton. I do know that I've adjusted a couple of my Canon screwmount lenses for better results on my R-D 1 by reducing the thickness of the "collimation shim" (brass ring that determines how deep the lens sits in the focusing mount) and this has produced good results. On the Canon lenses this is simply a matter of determining how much thinning is required (I put a formula into a spreadsheet to do this) and then rubbing the shim against a sheet of fine sandpaper on a flat surface, measuring with a dial indicator until the right amount of material has been removed.

 

[tmessenger]

I've been harping about this for weeks, all the used lenses I've tested except for 2 have required shimming to close focus correctly on my RD1. I even have differences with the same brand 50's, my chrome version 50/1.8 Canon focused correctly but the later model black and silver version back focused. The good news is lenses are easy to shim and both my Canon 50/1.8 and Leica Elmar-C 90/4 only required a .001" shim to correct. With such a minutia requirement to correct close focusing you can see why there can be problems. The other issue is if you are using a screw mount adapter it has to be the right thickness. I got a cheap adapter with a lens I bought and it was .005 to thick, that could really mess things up.

Tim

 

[Ben Z]

Maybe some of the problem is that these cameras magnify each lens 50%? Put a 75mm Summicron on any film rangefinder, Leica or Bessa, and it will be more sensitive to focusing accuracy than a 50mm.

Didier, what I did was get a refurbed Canon 20D, it cost me $800 US, has more pixels per square inch than the same area cropped from a 5D, and has worked perfectly from day one. I have a Tokina 12-24mm to cover the wide end due to the crop factor, but otherwise I'm using my same Pentax SMC-Takumars I used for 30 years and had abandoned.

 

[wintoid]

Thanks for all the input everyone.

Frustratingly, the 40mm f1.4 is one of my least favourite lenses, but I chose it to test because it had the widest aperture. I'm now anxiously wondering how the focus is with other lenses which are more important to me. I suppose I will have to test them one by one, or decide to forget it and just use wider apertures. Just to add more complications into the mix, my favourite lens is a Hexanon, which I gather is the subject of much discussion on the internet concerning focus accuracy.

My biggest hope is that the Nokton is the source of the problem. The Nokton is the only lens I have that I have never tried on the R2a.

I feel as though all this testing and pixel peeping is taking me away from the fun I was having taking photos with the thing. What a shame.

 

[Jim Watts]

At the moment I don't really know what to think. I pixel-peeped the RD1s because I have felt over the last 3 months that something wasn't right. I've only pixel-peeped it with the 40 Nokton. I've never felt that way with the R2a. I don't think my analysis is affected by the fact that one is digital and one is film, as I'm a negative+scanner guy and not a wet printer.

If they send the camera straight back to me with no alteration, I'll probably repeat my test with a different lens. For all I know, the problem could even be my eyesight!

Well given the consistency of focus with your original samples I doubt that it is your eyesight. I had similar doubts about my own eyesight when I got an R-D1 two years ago and found my 35mm Cron front focussed by about 3" at 3 feet. I felt certain I wasn't experiencing any problem on my film M4, but had never tested it. Given the time shift as mentioned here by others I decided to make the effort and test it to be sure, and it was fine on the M4

I also tested two further examples of a 35mm Cron (friends 3rd & 4th Series, mine's a 3rd) and these had almost identical front focus problems on my R-D1, which at least showed Leica sample to sample consistency with the lenses. Others in this Forum were not having problems with samples of this same lens on the R-D1.

This made me suspect the R-D1 body, so I tested all my other glass wide open with the following results:
21mm Avenon - Slight front focus, but covered by DOF, so not really a problem.
28mm Ultron - OK.
50mm Cron - OK.
90mm Tele-Elmarit - OK.
and now 40mm Nokton - OK.

This seemed to excuse the body, but left the problem. If I had the lens adjusted to the R-D1 it would be out on the M4. In the end I decided to live with the problem by making an allowance and back focusing a little in the situations where it was likely to be a problem.

I know it is a pain and like you I prefer taking photos to testing and Pixel Peeping, but I think here it is worth your while to do a controlled test of the 40mm Nokton on your R2A. If the lens is out by the same amount then you could adjust it to match both bodies. If not, as in my case, test all your glass on the R-D1 to determine if there is a fault with the body. If this is fine and your 40mm Nokton is still under warranty you may be able to change it for another sample that gives a more accurate result, or as it is your least favourite lens decide to sell or live with it.

My Cron was my most favourite (at least on an M4), but I'm starting to love this sample of the 40mm Nokton.

Hope it all works out for you.

Jim

 

[wintoid]

Jim, your post was especially useful to me. Thank you for the sanity check. In fact, as I don't care about the 40mm too much, I'll probably test the Hexanons on the RD1s when I get it back and see whether one (or more) of them works well.

I think where I went wrong was that I assumed all lenses would behave the same. It seems that may not always be true.

 

[blakley]

Agreed, pixel-peeping must frustrate camera/lens manufacturers as much as the obsession with megapixels (consumer market) and high ISO noise (prosumer) market does. Photos just aren't designed to be looked at at 100% close up on a monitor, they're desinged to be printed and/or stuck on a wall and observed from a distance...

Hmm? I guess you don't use a grain focuser for darkroom prints?

 

[Sailor Ted]

I don't know what to do. I also purchased my camera from Robert White and now it has a serious range finder misalignment (this happened somehow after just three days of ownership). I love the camera however it is so out of alignment that I cannot hold focus on a subject 3 meters away with my Zeiss 21mm 2.8 lens wide open (the focus point is actually at 2.2 meters). Since I live in the US I am debating sending it back to Robert White for replacement (it's less then one month old) or sending it to DAG for calibration. The dilemma is that if I send it to DAG I will void my warrantee however when pressed I find there is no way to determine if DAG ever opened my camera in the first place. Since any R-D1 is liable to go out of alignment at any time perhaps I should send it to DAG first, see if he can fix it (it won't be the only time I'm sure) and if the camera is other wise 100% OK just keep it- if not then send it to RW for replacement under warrantee.

Any ideas?

 

[jlw]

I may be old and cranky but it woud seem to me to be a simple solution to all of this. Get a good single lens reflex that is digital. One would see what the lens actually did.

What, there's a digital single-lens reflex that accepts M-mount lenses? No, I didn't think so.

Besides... if I wanted to shoot with an SLR, I would. I don't, so I want to make sure my RF cameras work properly. Not an unreasonable expectation, I think...

 

[jlw]

I don't know what to do. I also purchased my camera from Robert White and now it has a serious range finder misalignment (this happened somehow after just three days of ownership). I love the camera however it is so out of alignment that I cannot hold focus on a subject 3 meters away with my Zeiss 21mm 2.8 lens wide open (the focus point is actually at 2.2 meters). Since I live in the US I am debating sending it back to Robert White for replacement (it's less then one month old) or sending it to DAG for calibration. The dilemma is that if I send it to DAG I will void my warrantee however when pressed I find there is no way to determine if DAG ever opened my camera in the first place. Since any R-D1 is liable to go out of alignment at any time perhaps I should send it to DAG first, see if he can fix it (it won't be the only time I'm sure) and if the camera is other wise 100% OK just keep it- if not then send it to RW for replacement under warrantee.

Any ideas?

If I were you, I'd send it back to RW first, and here's why: Having the RF go out of alignment in three days is NOT normal. Mine has been extremely stable. If yours has some kind of internal defect (such as an out-of-tolerance part) that allows the RF to slip out of adjustment, sending it to DAG will just be a wasted effort -- there's no telling when it will go out again, and you'll lose confidence in it and be reluctant to use it.

I think we've all gotten so paranoid reading about R-D calibration issues that we assume that the RF is always on the verge of going "off" and that any unsharp picture we make must be the result of an RF problem (and not a lens problem, adapter problem, camera movement, subject movement, photographer error, etc.)

I went around that whole merry-go-round -- adjusting the RF myself, sending it to DAG, worrying about it endlessly -- and finally concluded that most of my focusing problems were either my own fault or the result of faulty third-party screw-to-bayo adapters or old screwmount lenses that were collimated to different standards, not the issues with the R-D's rangefinder.

I addressed those issues and haven't looked back. Now when I pull out my R-D 1 I just assume that it will work properly, and that I'll get sharp pictures as long as I do my part (focus the lens correctly, hold still, make sure there isn't too much subject movement, etc.)

And that's the way it's supposed to be. A "proper" R-D 1 is just as solid and reliable as any other RF camera, and there's no reason to expect anything less.

So, if I were you, I'd send it back to RW, tell them that the RF alignment was perfect when received but slipped out after only three days of use, and that this indicates an internal defect. It may be that it can be repaired or it may need to be replaced, but you're entitled to an R-D that is correctly calibrated AND holds that calibration.

 

[Adam-T]

I ended up tuning mine myself after Epson had a go (Glad they did a they removed the gunk from the screw) - the 35 F2.5 always focussed OK but I feel that it has a very wide tolerance also, the Ultron 28 needs a camera which is pretty spot on amazingly (despite being wider) as does the Nokton 50 (not suprising), I calibrated the RF at infinity with the 50 Nokton and all is well, I`d NEVER use 35 F2.5 at close range to calibrate this camera, it`s asking for trouble..

At least I can now tune the thing myself easily if it goes out again, I wish DSLRs were this easy