D.I.Y. Leica "Retrovid" 7x35 focussing improvement. (1 Viewer)

[HenRun]

Paul, I did a thorough scientific experiment just now.

I removed the gaskets and tried operating the focuser with the fingers recently dipped in a wetting agent. I don't know the common household name for the compound but the solution goes under the name of H2O.

With this wetting agent applied to the index finger I could operate the focuser to my satisfaction and would deem the addition of further traction to the wheel ribs quite unecessary. It worked smoothly and did not cause any operational discomfort. This is how I imagine the average person with normal dermatologically conditioned fingers would operate the apparatus.

With desperately dry digits the story was different and I found that without any friction assistance the digits struggled to achieve the proper turning of said focusing wheel, causing field stop anxiety. With the addition of the flat stay-in-place model silicon gaskets I found that the user experience was greatly enhanced.

The experience without the gaskets in place was in this case similar to having a plastic spoon between the finger and the wheel and loss of traction was considerable. This represents the outlier of individuals with less than ideal for operating focusing wheel (a.k.a bone dry) fingers.

This was a double blind study, I covered both lenses and closed my eyes to make sure I would not fudge the data in order to arrive at a scientifically sound conclusion in the matter.

I ran the numbers by a trustworthy source of one liners and the conclusion was (and I quote): People are different, and so are opinions.

 

[Paultricounty]

Paul, I did a thorough scientific experiment just now.

I removed the gaskets and tried operating the focuser with the fingers recently dipped in a wetting agent. I don't know the common household name for the compound but the solution goes under the name of H2O.

With this wetting agent applied to the index finger I could operate the focuser to my satisfaction and would deem the addition of further traction to the wheel ribs quite unecessary. It worked smoothly and did not cause any operational discomfort. This is how I imagine the average person with normal dermatologically conditioned fingers would operate the apparatus.

With desperately dry digits the story was different and I found that without any friction assistance the digits struggled to achieve the proper turning of said focusing wheel, causing field stop anxiety. With the addition of the flat stay-in-place model silicon gaskets I found that the user experience was greatly enhanced.

The experience without the gaskets in place was in this case similar to having a plastic spoon between the finger and the wheel and loss of traction was considerable. This represents the outlier of individuals with less than ideal for operating focusing wheel (a.k.a bone dry) fingers.

This was a double blind study, I covered both lenses and closed my eyes to make sure I would not fudge the data in order to arrive at a scientificallyt sound conclusion in the matter.

I ran the numbers by a trustworthy source of one liners and the conclusion was (and I quote): People are different, and so are opinions.

I’m going to discuss this lack of bone dry finger deficiency in the retro design at the next board meeting at Leica. In addition I’m notifying all R&D for design solutions and alerting all the shareholder of the issue. May I suggest finger moisturizer as a temporary solution to the plastic spoon traction debacle.

Seriously though, I know what your saying and understand this seems to work for you. I’m just not getting how a dry piece of dry rubber would give you more traction than a metal knob with machined grooves meant for finger traction 😉. Everybody is different , that is for sure.

 

[HenRun]

It was meant as tongue in cheek. 🤓
The rubber gasket is perhaps drying out with time but the positive effect it has is real. I really need it on my Retrovid.

You do not want to see what my friend did to his Ultravid HD Plus 8x32 for focus wheel traction. It was not as discreet. 😁

#seeyouattheleicaboardmeeting

 

[MiddleRiver]

7x35 focus is not the fastest and an o-ring would increased the diameter which would make it easier to turn, I think. But overall I don't mind the longer-throw focuser. I love being able to fine tune it. The UV sometimes seem too quick to me and I'm sure they're not the fastest kid on the block!

 

[Paultricounty]

7x35 focus is not the fastest and an o-ring would increased the diameter which would make it easier to turn, I think. But overall I don't mind the longer-throw focuser. I love being able to fine tune it. The UV sometimes seem too quick to me and I'm sure they're not the fastest kid on the block!

I know exactly what your saying about the two. You can just slowly dial in a perfect snap to focus in the retros. The Ultravids (all of them) have a kind of a focus hair trigger. It’s easy to get focus no doubt, bit it’s a small spot on the focus wheel. Both are nice in there own ways, but so very different.

Paul.

 

[John M Robinson]

I think it’s, to each his own on this modification. I have to agree with Jerry here, the focuser on my 735 is butter smooth and probably better than the four other Leica’s I own, it’s very similar to my noctivids except slower, which I think are one of the best in the business.

Two points that were made that led me to try it & why you see it as an improvement. Your statement (I believe it was you) said that under long duration observing the focus wheel ribs were irritating your finger. The other that the o-ring makes the wheel smoother.

I found the focus wheel has better grip without the o-ring when my hands are a little sweaty. I think considering this post that it’s possible you have a defective focuser. It should be light, smooth , no play , no stiction or any binding. If it does have any of those traits I can see how it would become irritating over time and the mod would help. But it really shouldn’t need it. IMHO.

just sitting at my window with a cup of joe as you, enjoying the asphalt jungle.

PAUL

I agree you and Jerry, I love the focuser, but if others don’t like it, and they found a simple fix, more power to them.

 

[montynj1]

I loved the idea and gave it a good try. First using just one o-ring over the focuser, then two. It gave a nice tactile feel, different, but not sure if better. I enjoy the focuser either way. The issue that I had with it is that it/they, wouldn’t stay in place on the focuser knob. Every time I put the binoculars in, or took it out of its carry bag they came undone. To make this a permanent improvement would mean you would have to use some kind of adhesive. And I’m not willing to do that in the event overtime I want to go back to the stock grooved focuser.

But I like it.

There is an alternative to using an adhesive tape. There's this product called Alien Tape that is a very soft and sticky tape without using any adhesive. I recently tried it out on my hack and after several (and I do mean several) tries, I was able to make it work. I had to remove the tape from the focuser a number of times because it was very difficult to work with and on each occasion it left no sticky residue. The tape is very soft and malleable and that made it very difficult to work with. When I try to put the gasket over the taped focuser, the tape would stick to the gasket before I could get the gasket into the position I wanted. I finally realized that I didn't need to cover the whole focuser with the tape but rather just a couple of spots on the focuser was enough. It does feel more secure on focuser as a result. I would not recommend buying the stuff just for this hack ($20.00 for 3 rolls in most stores), but if you already have it, it is something to look into.

 

[John M Robinson]

I bought mine by mail order, sight unseen based on reviews and fond memories of my old Leitz Trinovid 7x35. About a decade ago we had multiple threads discussing the old Leitz and pining for an updated version with modern glass and better coating. I was surprised when Leica finally did it, though not with upendahl prisms. Anyway, I love my focuser, very smooth and wonderful tactile feel, but I don’t have a problem if somebody wants to fit o-rings on theirs.

 

[lmans66]

Remember that the retro 7x35 is just that....a retro. The original 7x35 had the same focus issue I believe as did many of the bins back in that day such as the dialyt. While even in my comments about this binocular I have mentioned the focus design as being a bit slow, I haven't felt it took away from the binocular at all as this is my main bin.

But in the spirit of things, I will experiment with the 25mm / 15/16" o-ring. Yet the retro is retro for a reason, keep that in mind.

 

[HenRun]

I agree with the retro comments. I don’t mind a slow focuser. I don’t have a problem with the design or the mechanical feel or precision of the Retrovid.

After giving it some thought I realise that my very dry hands and fingers will not work well with any metal focuser that has some resistance, now matter how nice the mechanical feel.

I have the same problem carrying sheet goods - I waste a lot of energy pinching when carrying without grippy gloves. And still I am slipping. With grippy gloves I can relax and carry with very little effort.

 

[lmans66]

I used my retro with the o-rings on the focus knob.... Quite frankly I didn't notice a difference. In fact, I didn't even know there were on so nothing major to report. They stayed intact and 'on'.... but as far as making an impression on my in terms of ease of focus or lack of or whatever, ...nada....

 

[kimmik]

Didn’t want to start a new thread for this, but similar idea - improving the focuser on the trinovid pocket.

pocket models focuser bind up when folded, now after i put some felt tape on as spacer the focuser can be used even when folded up. Great for a quick spotter scope like use not having to unfold everytime.

 

[hopster]

Hmm, are we using same diameter gaskets? Mine are still going strong with daily use. Not hours on end, but daily use.
I would not glue anything to my Retrovids either.

My gaskets are flat, not rounded and slightly less than 25mm.

Flat cross-section will be helpful in this application and will make a lot of difference to it staying put. Also, a thinner rubber will let the ribs 'poke through' to some extent providing the best of both worlds. If I get my hands on one I would first try the cut cross-section of an old (narrow) bicycle inner tube. This nitrile rubber is very tough and grippy, but thin enough that the ribs would be felt through it.

 

[lmans66]

I wouldn't spend much time worrying about that..... as mentioned earlier....I tried to use an o-ring and found little difference. Now, if you are using this 'all day'....okay...I can see a benefit but going out for a few hours makes little difference.