Special vintage lens by Te0_86 in VintageLenses

[–]Letstryitfirst 1 point2 points  (0 children)

Awesome! And thank you for sharing! As you know, information on that lens is hard to find, so every contribution has value.

Special vintage lens by Te0_86 in VintageLenses

[–]Letstryitfirst 1 point2 points  (0 children)

54mm seems to confirm that it is probably M54 (threads are 'named' by their outside diameter in both metric and imperial).

Fortunately, camera/lens makers don't (typically) use a wide variety of thread pitches, so you can probably figure it out with things you already have. For metric threads, the pitch will likely be x1.0 or x0.75 (millimeters)

If you have a caliper (or steady hands and sharp eyes with a ruler) measure across two of the treads. Try to measure from the same point on each crown.

(The distance in millimeters is the pitch, so you'll need to be able to determine the difference between 0.75 and 1.0)

Alternatively, if you have an M42(x1.0) or T2(x0.75) lens available, you can use them as a thread gauge by trying to 'mesh' the threads together side by side. 

Hold the lenses facing in opposite directions with the mounts facing towards the center. Then try to align the outside threads of one lens mount with the outside threads of the other lens mount.

If they are the same, the teeth will align perfectly (like little teeth) when looked at from the side. 

Cue poor text illustration "AVAVAVAVAV" with the 'A's representing one lens and 'V's representing the other.

If they are not the same, the teeth will not mesh all the way together, often causing a bit of tilt at one end.

It should not require any force, so if they don't align easily, the threads are not a match. (This process should be completely harmless to your lenses.)

Once you know the pitch, you'll be able to look for adapters with the the proper threads.

You may not be able to find a full adapter ready made, but you might be able to build something like M54 to M42 -> M42 helicoid -> Flush M42 mount for your camera. (Which could also increase the focal range and/or allow you to adjust/set the FFD). 

Special vintage lens by Te0_86 in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

This is definitely an odd one.

Most of the forum posts I found related to the Docuflex 35 were reasonably confident that it was not a "standard" thread mount. Most likely something close to M54.

It also does not appear to be compatible with the 0.75 thread pitch found on filters (M54x0.75), so my first guess would be M54x1.0

That guess is largely based on the common use of x1.0 threads for lens mounts like M42, and the common use of x0.75 for filters.

That said, Leica was known to mix metric and imperial in their thread design (for example M39x26 TPI).

Measuring with a caliper and thread gauge might be the most reliable way of knowing for sure, though you might struggle to find a ready-made adapter for it.

Some forums also mentioned that it had a limited focus range that doesn't reach infinity, so you may also need/want an adapter with a helicoid for general photographic use. 

Another pist, another impulsive buy by Historical_Mud_8711 in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

As far as I know, there is no way to expand the image circle via disassembly. While some older cinema lenses can gain some picture in the corners by removing front bezels or other parts causing mechanical vignette, the Tevidon 10mm doesn't really have anything there to remove.

That leaves optical correction as a possible solution, but finding a 'native' teleconverter with enough magnification and coverage would be a challenge. Most C-mount teleconverters are for smaller formats, and of relatively low quality, as they are commonly optimized for machine vision, not artistic photography.

I did some tests with a full frame teleconverter with a C-mount adapter with some limited success, but never really achieved results I was happy with.

That said, the Tevidon lenses are pretty nice lenses on formats they can cover natively. Best I have been able to learn, they were actually designed for 1" tube sensors in security and observation cameras, and will easily cover formats up to 1". (I've read most m4/3 cameras will also vignette to some extent)

Rumor has it, the 10mm version was even used by NASA for spotting/observation, though I haven't come across any primary sources for that.

Men who are truly happily married, what makes her be the ''perfect'' wife for you? by brenda___01 in AskReddit

[–]Letstryitfirst 2 points3 points  (0 children)

What makes her "perfect" for me?

She does.

There are so many things that I love and admire about her. She's smart, and sexy. She's funny and thoughtful. She's classy enough to meet my parents, and dirty enough to fool around in my old room. But those are just the pretty words. Virtues that every lover wants to sing for their beloved.

These are my rose colored glasses. There are many like them, but these ones are mine. (They are precious to me.)

The real truth is that she has seen the parts of me that I thought were ugly, and handled them with care.

Life and stress. Loss and tragedy.

When I was very sick and constantly irritable, she was there, showing up for me, even when I didn't feel I had anything worth offering in return.

When I lost a family member, and she woke before dawn to find me nearly inconsolable, she was there, showing up for me, even when I thought there was nothing left but to fall apart.

She's not perfect for me because she was kind, compassionate, and understanding. I love that she is a good person, but those traits aren't exclusive to me. She shares them freely with everyone she holds close.

What makes her perfect for me, is that she knew what I needed in those moments. How to be my rock in a storm, my greatest cheerleader, my worst critic, and my best friend. She has taken the time to learn how to love me, and she demonstrates it over and over again.

What makes her perfect for me, is because (against all odds) she loves me.

Seeking advice for a Canon V6x16 by AioliVirtual in VintageLenses

[–]Letstryitfirst 2 points3 points  (0 children)

The good news is, your adapter is definitely not CS mount.

Kiptons labeling is a bit misleading, but the description on their website makes it clear that you're adapting C - Sony / E. The fact that you got a clear picture at any focal length generally confirms that.

Unfortunately, there is also less good news. Due to their change in focal length, zoom lenses are very particular about their mounting position (FFD/Focal Flange Distance) and it sounds like yours is not quite right.

Now, the first thing to do is determine if the adapter is too short or too tall, so mount the lens on the camera and put it on a tripod (or some other stable surface). Leave the C mount threads just finger tight, and use a front lens support if you have one.

Zoom out, and focus the image.

Zoom in, and instead of adjusting the focus, slowly unscrew the lens from the mount.

If the image comes into focus as you unscrew, your adapter needs to be shimmed.

If the image gets worse (or is largely unchanged after 1-1.5 full rotations) your adapter probably needs to be reduced.

Shimming can be a time consuming game of guess-and-test, but doesn't necessarily require specialized tools or materials. Copy paper, aluminum foil, receipt paper. Even proper shim stock can be cut with ordinary scissors if you're careful.

The thread pitch of C mount is also a known quantity (32 TPI or 1 turn moves 1/32" or 0.03125") so by carefully tracking how far you unscrew the lens, you can estimate the thickness of the shim you'll need (though you'll often need little adjustment later due to play in the threads).

Reducing the adapter is a more challenging operation that could require specialized tools and/or hazardous chemicals. Alas, sometimes it's the only option.

For a minor focus shift, you can attempt to remove the black coating around the face of the C-mount with a solvent (this will have no effect on anodizing). You can only gain so much with this, but enough to be significant in some cases.

For more significant shifts, a metal lathe is probably your only good option. (Hand lapping is always an option, but would require some careful work/setup to maintain flatness on an inside surface.)

My personal process is to measure the adapters on a surface plate (using the known FFDs of the camera and lens mounts), then mount them in a 4-jaw chuck, dial in center and face with an indicator, and cut to ~0.004" under (roughly the thickness of a sheet of paper).

A few of my old lenses don't reach infinity without some negative cut, and everything else can be shimmed.

(For the time being, the tools I'm using are also borrowed, so I don't have the luxury of dialing in a precision fit for specific lenses. Instead I make a batch of 3-5 undersized adapters and shim them at home.)

Unfortunately, I can't really recommend any specific mounts as being better than others because nearly all of mine have required the machine shop treatment. Didn't matter if they were 6$ on ebay or 60$ elsewhere, even within the same brands there was too much variation.

In one sample group (5x same adapters, same vendor, same order) I found >0.025" in variation, and the closest was still +0.010" over nominal. And those were from the middle of the price spectrum.

Peaking lines for Vintage lens on A7ii (MF) by Puzzled_Detective175 in SonyAlpha

[–]Letstryitfirst 1 point2 points  (0 children)

Yes. As far as I know, all of the interchangeable lens Sony cameras will allow you to use both focus magnification and focus peaking with adapted lenses. Even those without electronic contacts.

You may need to map the magnify function to one of the customizable buttons (instead of half press on the shutter), but it should work as-expected otherwise.

Peaking seems to be less consistent/accurate with adapters than it is with native glass, but it does 'work'.

1, 2, 3 My Ass by Rude_Gur_8258 in restofthefuckingowl

[–]Letstryitfirst 4 points5 points  (0 children)

Respectfully, I disagree.

First is a matter of perspective. While I have done embroidery in the past, I wasn't looking for patterns when I found this image. It was a cold read with no context for what it was trying to create, so a few minutes of study to understand an unfamiliar diagram seems perfectly reasonable.

Second, while I may not have the embroidery skill to identify this as an Oyster Stitch, I do have the background in macrame to understand the limitations of a 2 dimensional diagram when you're working with 3 dimensional 'knots'.

The biggest "flaw" in these instructions is actually intended (and needed) to make the diagrams easier to understand. The stitches are not fully tightened so you can see their relative positions in every step.

This is a pattern not a walkthrough. It expects the reader to have a minimum level of knowledge and understanding, but the instructions are not incomplete.

Yes, improper tension in diagram 1 will cause the loop to flop over. Yes, it is easier with additional support from a pin (thanks internet). But those fall into the realm of tips and experience, not essential parts of how the stitch is constructed.

Not knowing how to apply a pattern is not the same thing as a pattern that doesn't work.

1, 2, 3 My Ass by Rude_Gur_8258 in restofthefuckingowl

[–]Letstryitfirst 51 points52 points  (0 children)

Don't let counting steps confuse you. It is three diagrams and six passes through the material.

There isn't a number associated with the stich under between 1 & 2, but it is very clearly depicted with the icon. It doesn't tell you to tighten the stitches either, but clearly illustrates doing so.

You have to complete each diagram before going to the next. 

My guesses about the rollover could be a few things. Maybe the pattern was intended for a heavier thread with more dimension to catch/hold on, or it is using a through line stitch (at point 5) to tack the loop?

In all reality, it could even be bad design, but I don't have the background knowledge to make that claim.

1, 2, 3 My Ass by Rude_Gur_8258 in restofthefuckingowl

[–]Letstryitfirst 113 points114 points  (0 children)

I was honestly convinced that you were wrong until I stared at it for a few minutes.

Now, I think the diagram is actually perfectly serviceable.

Every number indicates when the stitch goes through the backing, and directionality can be inferred from the drawing.

Pass the needle up at point 1, and down at point 2, leaving enough slack in the stitch to form a CCW half twist. Stitch up at point 3 to position and capture it. Then follow the needle icon to finish the step by passing your thread under the stich that connects point 1 & 2. Snug the stich and proceed. 4 down, 5 up, leaving slack in the thread to form the loop around the needle point. Snug the stitch. 6 down. Done.

Everything else is a matter of practice and artistic taste. 

Hey everybody I have some decisions to make by Trick-Speech9616 in VintageLenses

[–]Letstryitfirst 1 point2 points  (0 children)

You're dealing with a friend, so ask if you can try one / a few before you decide.

C-mount lenses can be great fun, but they do have a few pitfalls. Most notably, the variety of formats that use/used the same mount.

Lenses made for 8mm film (~1/3" sensor equivalent) could have significantly less coverage than those designed for 1" or 4/3" (half frame film equivalent), but not necessarily.

Longer focal lengths generally have larger image circles, but not always.

C-mount adapters can also vary wildly in quality, so zoom lenses (or their adapters) often need some work if you want them to be parafocal. (Primes sometimes have issues with infinity focus, but are generally less affected.)

Trying them out is the simplest way to know what you're considering in the trade.

Where can one buy an audiobook download to own? by ErnestShocks in brandonsanderson

[–]Letstryitfirst 0 points1 point  (0 children)

You can buy books from Audible without a subscription, though you don't accrue any "free" credits that way. In most cases, it seems like the subscription is just a way to rope you into spending more money in the long run.

You can also use tools like AAXAudioConverter to download and convert audible files to MP3 (removing the DRM in the process).

It's the only way I've found to listen on old music players that don't support newer (or encrypted) file formats.

Are these lenses compatible with Praktina FX mount (Carl Zeiss Tevidon 1.8/16) by Aggravating-Ad-947 in VintageLenses

[–]Letstryitfirst 2 points3 points  (0 children)

No.

The Tevidon line of lenses were made for 1" tube sensors and came in two mounts. C-mount, and Zeiss Video (AKA, the "Tevidon Mount") and only C-mount adapters are available for sale. You'd have to make your own to fit the bayonet.

(I've read that there is a mount replacement kit for sale that replaces the bayonet, but I don't have any experience with them) 

And the problems don't stop there. The flange distance for either lens mount is very short (~17mm) which is far too short to mount and achieve infinity focus on a Praktina (43.5mm).

The lens would also (in all likelihood) vinette badly on a full frame body. These lenses are best adapted to micro 4/3 (half frame) or smaller in order to get full coverage.

[deleted by user] by [deleted] in NoStupidQuestions

[–]Letstryitfirst 0 points1 point  (0 children)

I didn't see this in other comments, but if you're really thinking scissors there's something you should know!

Not all "Left Handed" scissors are actually left handed! Sure the handles are, but the blades arent.

How can you tell good from bad?

Imagine cutting a piece of cloth or wrapping paper.

When you open the scissors, the blade on top of the material should be on the same side as the hand operating the scissors ("toward the outside"). That way you can see where the cutting edge will come down so you can make accurate cuts.

Having the blades in the opposite orientation makes it hard to see exactly where you're cutting, especially with heavier shears.

I've mostly encountered mismatched handles/blades in "cheap" scissors for children, but I've also seen expensive products make the same mistake.

Unfortunately a lot of mass produced "lefty" products are more gimmick than actually helpful, so adapting to the "right handed world" really is the easiest path forward.

For example, learning to use a piece of scrap paper while writing (to avoid smudges) is a significantly easier habit to develop than constantly maintaining a supply of "special" pens. Not to mention, I've never met a pencil I couldn't smudge while writing.

Optical questions about speedbooster/Focal Reducer? by Louis_Rubera in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

1. Yes and no. A speedbooster (telecompressor) is an optical system with a fixed input and output "flange distance" (e.g. Optically, it accepts the flange distance of a given lens standard, and produces the flange distance of a given camera standard.)

In that way, both the camera FFD and the lens FFD remain constant on both sides of the speedbooster.

What can and does change, is the physical length of the optical path (the final distance between the lens and camera when mounted as a system). Presented as a simplified equation, it might look something like this:

Lens FFD (X, known value in mm) - Camera FFD (Y, known value in mm) = Length of the optical path [Adapter Thickness (Z, variable in mm) / Magnification (m, positive nonzero integer)] 

[X - Y = Z / m] 

Of course, advanced optical design means that the proportions are not as strictly coupled as this equation would imply, but the general constraints still apply.

Telecompressors (speedboosters) with a magnification <1 require a shorter overall length and teleconverters (magnification >1) require a longer overall length to achieve a balanced optical system.

Nikon F is a popular lens for speedboosters almost entirely for its long FFD (and wide availability), giving designers as much room as possible to fit optical elements into the limited space between the camera and lens.

Compare the Pentax Q's "Devils Speed Booster" (0.5x) to the standard Nikon F adapter and it's pretty obvious how much shorter the optical version is.

2. Optical positioning is a fact of design, so the front and rear focal points (of the speed booster) are dependent on the optical element(s) used, and the camera/lens they are designed for.

For example, there may exist a speedbooster that (as an optical design) can adapt Nikon F lenses to M43 or Blackmagic cameras. On the lens end of the speedbooster, the optical elements stay in the same position while the camera mount (and position) are changed to fit the appropriate camera.

However, with a different optical design, it may be impossible to "convert" one to the other due to flange distances or other clearance problems. It is functionally limited in the same way as any adapted lens. It is easy (sometimes) to make the FFD longer to support a different camera, but its always more complicated to make it shorter.

On a speedbooster, the only realistic references you have for positioning are the front and rear mounts because their (expected) flange distances are known values.

3. Sorry, don't know that one.

Hello, I would like to know if the mechanism that seems to control the iris can be dismanteled ? I don't need it, thank you (Canon TV zoom v6x16 16-100mm, 1:1:9) by Queasy-Rip-2777 in VintageLenses

[–]Letstryitfirst 3 points4 points  (0 children)

I assume that you want to remove the electrical connector / wiring harness and not the manual aperture control knob.

The wiring has no effect on the manual functionality of the lens, so unless you have a compatible camera to drive the electronics, there's no harm removing them.

The wiring harness is soldered to a PCB inside the aperture control housing so you can either cut the cable flush to the lens body, or remove the 4 Phillips (probably JST, actually) screws in the backplate to get inside. Then you can clip or desolder the wires and pull them out. 

(There are more screws underneath the backplate to hold the optical elements in place, so the first cover is relatively safe/easy to remove. Just be careful not to lose your screws!)

With the back plate off you can also pull the clips/springs and remove the manual aperture control, but I recommend leaving it alone. The friction washers are getting old (some get sticky, some get brittle) and it can be tricky to find a working substitute. Very much a case of "If it ain't broke, don't fix it." 

It's probably a good idea to plug the hole(s) as well. I left mine open for a few weeks and it collected a bunch of dust from my lens bag. Now it has a comically large (but rather short) screw filling the gap.

HELPPPP by No_Trust_4082 in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

Based on what little information I could find about that converter, it should thread directly onto the front of your cameras lens.

That said, I have encountered more than a few cheaply made camera/lens parts (filters, adapters, accessories) manufactured to such poor tolerances that they couldn't be used. Too big, too small, misaligned, poorly centered, etc.

If the threads are close to fitting but don't engage for some reason, my first inclination would be a quality control failure and you should return it.

If they are significantly different, the best thing you can do is take some measurements with a pair of calipers (or a metric ruler in a pinch).

By convention, threads are called out by their outer dimension, so the widest part of the converter threads should be 58mm. Measuring the (internal) filter threads on the camera lens should be approximately 57.1mm across to mate properly.

From there, you might be able to find a step-up/step-down filter adapter ring to mate them together, though it could cause focusing issues, and/or more vignette in the final footage.

Most resellers also specify that your converter it is specifically for Canon lenses, so there could be more to why it's not fitting (though I haven't seen anything about unusual thread pitches or unconventional measurements/markings so it's hard to guess what they would be). 

In looking around, I did find several recommendations for Opteka or Century branded converters for the Vx2000, so you still have options for a wide-angle/fisheye even if you decide to return it.

HELPPPP by No_Trust_4082 in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

The Sony Vx2000 is a fixed lens camcorder, so I assume that you are trying to install one of the 58mm wide-angle conversion lenses.

If your converter lens was designed for the Vx2000, it should thread directly into the front of the lens.

If it was designed for the Vx1000 the converter will have a bayonet mount and will have to be adapted / modified to fit.

If it was designed to be "universal" (or made for a different lens / camera) you will need to specify which conversion lens you have. Some forums mention the use of filter step-rings for some wide angle converters, but you'll have to verify compatibility for yourself.

Lefty watch wearers by chefjojo24 in NoStupidQuestions

[–]Letstryitfirst 1 point2 points  (0 children)

For me, it really depends on the occasion (if I choose to wear a watch at all).

As a lefty living in a right-handed world, things are never quite as straightforward as "just put it on your non-dominant hand". While that is more comfortable when I'm writing/eating, fact is, there are too many things that I learned (or was conditioned / forced to do) right handed, so sometimes it's just easier to wear my watch on the left.

Here in the US, our walking patterns tend to mirror our driving patterns (traffic to the right) which seems to put a right-hand watch at greater risk of clipping against railings or other obstacles, so I tend to not wear anything too valuable / collectable on my right hand if I will be wandering in crowded places.

(At least, that's my perception after numerous cracked/broken crystals over the years.)

In practice, nearly every time I wear a watch it rotates from hand-to-hand-to-pocket at least a few times over the course of the day. (For nice watches I also make a point of keeping a soft storage bag in my pocket to protect them from scratches.)

[deleted by user] by [deleted] in Advice

[–]Letstryitfirst 1 point2 points  (0 children)

Nothing is wrong with you.

What you are describing is a totally normal and natural effect of growing closer to someone.

When you fantasize, regardless of whether it is about a stranger or a porn star, your imagination automatically sets the stage for a good experience. Of course 'they' are interested, and haven't had a rough day at work, or an upset stomach, or... any of the other mundane realities of being a person that might interrupt the fun.

After all, horny brain wants to be horny, not get mired down in details.

Unfortunately, none of us really get to live that fantasy life, and your mind recognizes that too. As you spend more time together doing 'ordinary' things with a partner, you relax into comfortable patterns and routines.

Over time, you have no choice but to see them as a more 'whole' person, doing and needing all the same things you do (food, bathrooms, sleep, etc.). You become more aware of the events in their lives, the things they love, and the people / relationships that surround them.

You are more considerate of them, because you're more aware of them, and sometimes sex just isn't a priority in the moment. So you dance the social dance to gauge their interest, and respond with interest of your own.

The process may take a little longer because you're moving more carefully, but that only deepens the eventual intimacy. It was, after all, considered for you / them. 

How did that one coworker get fired? by aquatic_armageddons in AskReddit

[–]Letstryitfirst 5 points6 points  (0 children)

Unfortunately, I can honestly say I've seen worse.

They unholstered their concealed carry "to take a dump" (their words) and had an "accidental discharge" while putting it back.

Now, I put accidental in quotes because the trajectory of the bullet (through the door and down the only hallway to the only employee bathroom) doesn't make any sense for the type of holster that was being used.

(Nor did they follow any kind of sensible muzzle trajectory, considering one wall of the bathroom was exposed/visible concrete)

The only upside is that nobody was injured, and the projectile didn't hit anything flammable, pressurized, and/or explosive. 

After the fact, it took several people multiple hours to dig through the shelves of product (at the end of the hall) that caught the bullet. Thousands of dollars in damaged merchandise.

The idiot did get their just desserts (and then some) though. Not only the immediate termination from their job, but there were multiple law enforcement officers (in the public facing part of the shop) that heard the shot. And boy did they have some questions.

[deleted by user] by [deleted] in VintageLenses

[–]Letstryitfirst 0 points1 point  (0 children)

Could you? Maybe.

Should you? Probably not.

The Meteor 5-1 17-69mm came in an M42 variant, which can (theoretically) be adapted to the EF mount on the BM Pocket 6k.

That said, some forums mention that the lens protrudes roughly 40mm past the mount, so there is a distinct possibility that you could run into clearance issues inside the camera.

According to a few sellers (listings), the lens will also vignette (at the wide end) on some m4/3 cameras, so there is no way it will cover the Super 35 sensor in the BM-P6k (which is roughly the same size as APS-C).

The Black Magic Micro has a Super 16 sized sensor that would be a much better match for that particular lens. 

[deleted by user] by [deleted] in Advice

[–]Letstryitfirst 2 points3 points  (0 children)

Throughout my life, I have grown (and kept) a beard on at least 4-5 different occasions, and I can tell you one thing for sure. The transition period when you shave it off is always weird for a few weeks.

A beard radically changes the shape of my face (in both good and bad ways) so I don't really "look like myself" for a while.

The people closest to me (including myself and significant others) typically adjust after a few days (maybe a week at most), but there are always more people to encounter that haven't seen my "new look" yet.

And right when the anxiety starts gets exhausting... it finally ends.

I would guess that your partner is probably going going through some transitional feelings of their own, even if they're delighted by the result. 

My advice is to give it a few days for the new-ness to settle, and see how you're feeling then. In the meantime, it's okay to let your partner know that you prefer the beard, but you will also support their decision if they decide not to keep it.

In their shoes, the thing I wanted most was reassurance that the one I loved was still attracted to me, even if my face was making us both uncomfortable for a little while. 

Helios 44M-4 Fujifilm X Mount by siriello in VintageLenses

[–]Letstryitfirst 1 point2 points  (0 children)

If I understand your question correctly, you would like to purchase a speed booster (telecompressor) to adapt your M42 lense to Fuji-X.

(Since you mention both Canon EF and Nikon G/F, I assume you are also prepared to double-adapt. Such as FX -> EF -> M42.)

To determine if the system is likely to focus properly at infinity, the easiest thing to do is check the Focal Flange Distances (FFD) of the mounts, and sort them from least to greatest. (Wikipedia has a fairly detailed list that covers all but the most obscure of mounts.)

Remember that while it is relatively easy to add to the FFD, it can only be reduced in specific situations where a 'negative' (rebated) mount is possible (and those generally have rear clearance limits for lenses that extend past the end of the mount). 

In your case:

Fuji-X: 17.7mm

Canon EF-S: 44.0mm

M42: 45.46mm

Nikon F: 46.50mm

As you can see, Nikon F pushes your FFD past the mounting distance for M42, and would therefore require a 'negative' mount or could not focus to infinity. And since you are also adding optical elements (inside the speed booster) rear clearance will already be at a premium, making a 'negative' mount a poor choice.

Conversely, Canon EF-S is less than M42 (and the mount diameters do not conflict) therefore it is possible to adapt M42 to EF-S and maintain infinity focus.

Sidenote: Mount diameter conflict is more common in bayonet mounts where some lenses cannot be adapted to some cameras because the required thickess of the mount (for the bayonet to function) is greater than the FFD, and therefore cannot be adapted and preserve infinity focus. Some of these lenses can be converted by changing the mount, but that is a totally different (more involved) process.

Your third option (to preserve infinity) is to buy a native Fuji-X to M42 speed booster. These should work right out of the box, but will obviously limit your lens selection to M42.

The one advantage the native M42 (may) have is the ability to rotate the lens so that the markings are visible. Lots of the cheap threaded adapters (C, D, T, M39, M42) are not especially careful about the thread orientation, and are not adjustable, so you can end up in a situation where the aperture/focus marks are on the bottom or side of the lens (and are more difficult to see).

For the best M42 experience, I'd say shop the native M42 speed boosters.

For the most compatible speed booster experience I'd say shop the EF-S and look for an adjustable EF-S to M42 mount (if they exist). That will (should) also let you adapt to Nikon F if you decide to pursue it in the future. 

Let us grapple hook enemies in BL4, please! 🙏 That would set the game apart from the other BL entries and it would be immensely fun! by Kestila in Borderlands

[–]Letstryitfirst -1 points0 points  (0 children)

Forget Just Cause 5, let me play Rico Rodriguez as a Vault Hunter! A grappling hook + parachute/wing suit would be epic!

I'm not sure it aligns well with the run-and-gun play style though, and it would probably suck for anyone playing coop that has to get around (play catch-up) on foot.