Sunday, December 4, 2016

Minolta Chyoko 4.5cm f3.5 Rangefinder Lens Conversion Part I

I know a lot of people just could not understand why anyone would even bother with a standard lens having an f3.5 maximum aperture.  Today's modern 50mm lens of f1.8 is considered slow.  So yes, why bother?

All I can say is that each lens has its place, and justification for its existence.  f3.5 is slow for low light photography, but there are many places where it can still make wonderful photographs, and you often find the photos they render is not reproducible by modern lenses.  The Minolta Chyoko 4.5cm f3.5 is one slow lens that I really, really like.

Minolta "A" in its original form.  Note the round design.  Very hard to hold and use.

This lens came from the Minolta "A" rangefinder, introduced in 1955 as an entry level rangefinder.  I have never held a more un-ergonomical camera than this one.  I think the design is terrible.  The camera feels like a melon in my hands, but we are only interested in the lens, so it's ergonomics is inconsequential. The lens came out quite easily from the camera with just a few screws from the front of the camera.

Lens is very easy to remove.  in fact, the lens can be removed without touching much of the camera body.

Lens as it came out of the camera.  Note the shutter mechanism at the rear of the lens.  Since we don't need it, it can be easily removed, and the best part of this, is that you don't have to worry about keeping the shutter open like most rangefinders with shutter assembly built into the lens.

The focus mechanism of this lens had very little damping so I decided to disassemble the lens to clean it and re-lube it. To do that, the front group of elements need to be unscrewed, but do be careful when removing it; this lens group is used to secure the aperture mechanism.  I made a mistake of tilting the lens while removing the lens group and the aperture assembly came out of its place.  Took me a long time to put the blades back.

Front lens group removed.  Note the aperture blades are just sitting there without anything else to second it in place.  The lens group is the only thing keeps it secured.  Don't tilt the lens while removing the lens group, otherwise prepare to spend a lot of time trying to put them back.

All the parts of the lens disassembled.  It's quite easy and simple.  Just remove all screws, but don't lose any screws and remember the sequence.

The disassembly of the lens is quite easy by removing the screws.  Be sure to note where the specific screws go and don't lose any.  The only tricky part, is putting the helicoid back.  You DO need to put the parts back at the specific location or the distance scale will not line up.  I usually mark where the parts separate, and this will help later.  Otherwise, you will have a lot of trial and errors and this is not a fun thing to do, believe me.

After the helicoid is taken apart, I used Ronsonol lighter fluid on a Q-Tip to clean off the old grease, and re-apply a light grease.  In a future post, I will talk about the different greases I tried and why I ended up with what I am using, which is Slickoleum Light Grease, that I also use for my bicycles chain and other parts.  This grease is light and provides the right amount of damping than the others I have tried.

Once the lens is cleaned and reassembled, the next part is the machine a spacer between the lens and the Pentax focus helicoid, which will act as part of the spacer between the lens and the Sony E-Mount.  With a lathe, this was very easy to do, especially when I decided to just glue the parts together, instead of drilling and tapping screw holds and use screws to hold them.

Simple parts required: on the left is a mount from an M42 2x teleconverter which I cut out.  Middle is the spacer I machined from aluminium.  The M42 mount will be glued to the top of this part. What's not shown is the rough marks I make on the surface to make the glue adhere better.  On the right, of course is the lens.

The other side of the parts. Note the screw holes on the lens.  If I wanted to, I can drill and tap the spacer and screw them together, but I find glue is strong enough.  I am still having trouble getting perfect alignment for screw holes.  I need a drill press, which I don't have, to do this properly. 

This lens has a rather long flange distance.  At first I thought it could be used on my Nikon D810, but no dice; it's still shorter than the very long F-Mount flange.  However, the distance allows the Pentax focus helicoid to be used as part of the space between the lens and the E-Mount, but just barely.

Minolta Chyoko 4.5cm f3.5 mounted on the Pentax Focus Helicoid and then on the Sony A7.  The lens itself has a focus mechanism, and can be used for medium to infinity focus.  For close up, I use the focus helicoid, or a combination of the two, for extremely close up.

In part II, we will take a look at what the lens can do.  You already had a peek from the picture in the last post, showing it's interesting bokeh.  We will explore more next time.

Wednesday, November 30, 2016

Blog Note

My apologies for the lack of posts lately.  It's not that I don't have anything to write.  In fact, I have written many articles but never published them.  I just find that my interest in the blog is weaning off.  Originally, I planned to do the blog for a year, or two years max, but did way more than that and it surprised me.  True, many of the posts have little or no substance but it was fun for me to write, and the blog kind of drove me to take more pictures and an excuse to acquire more gear :)

Another factor of the slowing down of my blog is the Flickr stream that I now maintain more actively.  It has taken up a lot of my time.  I often find that after processing my pictures, usually in the evening after work, and upload them to Flickr, I no longer feel like doing any more photography related activities for the rest of the evening.

Finally, the lathe project has taken up additional time, but I am very glad I got it.  So far, it has been extremely enjoyable and incredibly satisfying and rewarding.  What used to take me days to do with filter rings and other materials to make a lens work, I can now do it in a few hours, with more precision and better looking. I have learn so much, in a very short time, about lathes in general.  It's so true that reading about sometime and doing it are not the same.  Some things one must do it to learn, to acquire the skills, and to appreciate.  I have already found too many short comings of my micro lathe and started looking at larger lathes that allow me to cut threads, work on larger objects (not just for lenses), and be more efficient.

I do plan to update this blog more frequently, and probably more emphasis will be placed on lens conversion and using those lenses.  Also in the pipeline is doing some video of the lens conversions, but that will take even more time.  We will see what 2017 brings.

Berrilicious -- Minolta Chiyoko 4.5cm f3.5 from Minolta "A" Rangefinder & Sony A7

Monday, October 3, 2016

Rangefinder Lens Conversion - Some Experiments

So far I have done a few rangefinder lens conversions.  Some failures, some success.  On the whole, the later ones tend to be a bit better than early ones, so there is a slight improvement, which is encouraging.

From the very beginning, when I started doing rangefinder lens conversions, I like to preserve as much original parts of the lens as I could, especially the focus mechanism, but some lenses, because of the way they were designed, create a obstacles, and external focus helicoid must be used.  I like these lenses to have its original focus ring because they look aesthetically pleasing.  One of the issues with these lenses is their very long minimum focus distance, often at 0.8 to 1 meter, which makes close up pictures impossible.

The lens has been converted with an M42 mount.  When mated to the adapter on the left, infinity can be attained.  When mated to the adapter on the right, close focus is possible but no infinity focus.

As you can see, the two adapters have different thicknesses.  On the left, is about 3 mm thick for close focus, on the right is about 1 mm thick, for infinity focus.

Lens with normal adapter which will focus to infinity with minimum focus distance of about 1 meter.

In the past, the only way to get close up shots for non-lens-interchangeable rangefinders is to use close-up lenses.  This, however, changes the optical characteristics of the lens.  Since I am removing the lens from the camera, essentially making it an interchangeable lens, other close-up methods can be used, in this case, extension tubes.  So I have been experimenting with the idea of adding extension tubes.  Most commercial extension tubes have a minimum of 10mm, which is too thick for my taste.  I like to have some background characters in my pictures to show off the bokeh of the lens, so I don't really do super close-up, which usually renders the background to complete blur without any character.  This means I have to make my own extension tubes.

Sample close-up picture at about 0.5 meter.

For my latest conversion, a 4.5cm f2.8 lens from the Yashica J rangefinder, the lens has an M42 mount at the rear, which will screw onto a thin M42 to E-Mount adapter and will achieve infinity focus, but will have a long minimum focus distance of about a meter.  In order to get closer focus, I initially created a 5 mm extension tube, but found it to be too close so I created an adapter from an E-Mount reversing ring and an M42 ring, with a thickness of about 3 mm, which I find is a good balance between close focus and leaving enough background details.  This two adapter method is not as elegant or as practical as being able to focus from close up to infinity in a single lens, but I think it's a compromise I can live with.

I think this will be the direction I would like to take for new lens conversions.  We will see how it goes.

Empire Sandy - Yashinon 4.5cm f2.8 @f11 & Sony 7.

Friday, September 30, 2016

Nikon Is Anti-Legacy Lens

If you have a Nikon film camera with manual focus lenses, and you have just upgraded to one of Nikon's entry level DSLRs, you may find that the lenses you have do not work well with your new DSLR.  It simply won't meter and you can not set the focal length of the lens.  But, if you own a pro or semi-pro Nikon body, this is not a problem at all.  You can use any manual focus lenses, as long as you can mount it, and it will meter and stop-down if you set the lens data in the camera.

The inability to use legacy lenses on some of Nikon's DSLRs baffles me.  None of other camera makers does this.  On any Canon, Sony, Olympus, etc., one can use Aperture priority or manual mode and the camera will give you the correct exposure.  The mirrorless camera does  this better than the Canon as the meter always seems to overexpose as you stop down, but at least it's not crippled and you just need to dial in the proper compensation.

I was recently given a Nikon 1 V1 with a 1 inch sensor, in exchange for some work I did.  I thought I could finally use some of my c-mount lenses that have small image circle and are not fully usable on the M4/3 or APS-C cameras.  Upon some research, I found that the V1 (and probably all the Nikon 1 cameras) would only work in manual mode without any metering for manual focus lenses.  Every time I take a picture, I will have to set/check exposure. WTF?  And this camera has no live histogram!

On the other hand, the D810 works well with legacy lenses.  Why Nikon cripples basic features on some of their cameras that are available in all other brands' cameras is a mystery to me.

Pop Crew - Emil Busch Glaukar-Anastigmat 13.5cm f4.5 & Nikon D810

Thursday, September 15, 2016

The New Canon EOS-M5

The original Canon EOS-M, introduced 4 years ago, was sort of a laughing stock among mirrorless cameras, especially when it comes to auto focus speed.  If you haven't watched the "Mirrorless Party" video, or its sequel, done by The Camera Store, you will get a good chuckle out of it.  You may not know it, but this is the 5th iteration of the M line.  We had the original M, M2, M3, M10, and now M5.  Why the fourth model was M10, only the genius of Canon marketing knows, but the M5 is back in the proper place, as far as model number goes.

I had zero interest in the previous M cameras, simply because none of them had built-in view finder, electronic or optical, and the feature set was pretty spartan with a lackluster sensor to boot.  I care not much the lenses, as I would be using manual focus lenses most of the time anyway, but it is always nice to have the option of auto focus lenses, especially primes.  The M line has no fast primes, except the 22mm f2, which I heard is actually quite a nice lens and is affordable.  Canon has many low cost and excellent primes for the EF line, and those can be used with an adapter that supports full AF operations, but then again, mounting those on the M with an adapter would make it look bulky.

One of the aspects of this camera that slightly interests me, is the improved sensor.  The dual pixel AF should speed up the focus speed  considerably compared to previous M bodies, but I would not expect it to be even comparable to the newest mirrorless cameras from Fuji, Olympus, Panasonic, or Sony.  If the sensor in the 5D Mark IV is any indication, the one used on the M5 should have similar performances in terms of noise and dynamic range, which is definitely a step up from previous Canon sensors.

The downside?  It's not full frame.  I am not a full frame snob.  I still have the APS-C NEX-6, two M4/3 cameras, and now a Nikon 1 V1 with a one-inch sensor, but I have gotten so used to the look of full frame sensor that I use it most of the time.  I wish Canon would produce a full frame Mirrorless using current sensor technology.

So yeah, I won't be getting the M5, but it's getting interesting.  The build is definitely more robust than previous Ms and hopefully, this one will become the entry level model, and a more upscale, full frame M1 [note the missing 1 in the M line, reserved for the top of the line model :)] is in the works.

Blossom - Canon 35mm f3.5 from Prima Point & Shoot & Sony A7.

Tuesday, September 13, 2016

A Single Leaf

I was held captive for 10 minutes this morning by a single leaf that fell on the ground.  The yellow leaf, detached from the tree, seemingly smiling under the golden morning sun ray, hit me with such force that I had to stop, put away my bike, looked at it for a moment and then took out my camera.  I never question the power of nature to affect the emotion of human beings with its beauty.  In this case, one lone leaf left me awestruck.  Spent the next 10 minutes photographing this leaf in various positions.  Below is one of the frames.

One Lone Leaf - Meyer-Optik Trioplan 50mm f2.9 & Sony A7

Saturday, August 13, 2016

Minolta Rokkor-QF 40mm f1.8 Conversion Part Deux

I first converted this lens with filter ring and glue, as I wrote in this post with more pictures here.  It was a relatively easy conversion so I decided to redo it with the lathe, to hopefully make it look and work better.

Most of the conversion work was already done so this second conversion was pretty quick. I just needed to machine the spacer with the required thickness for infinity focus, drill and tap holes on the lens board and the newly machined spacer to attach them together, and then do the same for the E-Mount adapter, which was original a Rollei to E-Mount adapter with a missing lens release pin, and I decided to to use it as the mount.

The part at the right is the spacer I machined.  The left part goes inside the spacer.

I am quite happy with this particular conversion.  The lens fit together very well with no play and wiggles, except at the mount if you really twist it hard.  I did messed up the spacing of the mount and it's not perfectly centered, and this has the effect of off-setting the aperture index mark slightly.  Not a big deal but I could have done much better.  When I get more adapters, I will redo it, or, my next exercise, make my own E-Mount!  Another small problem is the focusing is not as smooth as I would like, probably because the focus guide hole is a bit tight.  Hopefully I can tweak it and make it feel a bit smoother.

Home made drill bit sleeve for the collet.

For this project, I used the milling attachment that came as part of my lathe.  It was used to mill the path for the focus guide to go through, and also used to hold the parts for drilling, as I don't have a drill press.  There is also a set of collets that came with my lathe but none fit the tiny drill bits, so I made a sleeve from the shaft of a Dremel bit.  A hole was drilled with the same drill bit that this sleeve will hold.  Once the hole was drilled, I cut a slit on one side of the shaft, thinking that should be good enough and it should give and clam on the drill bit when put on the collet.  But because it was made of hard steel, the sleeve didn't clam on the drill bit at all, so I had to cut more slits on the other side and is now working like a charm.

All done.  Looks pretty good, eh?  You can see the aperture index mark is off to one side.

This has been a good exercise for me.  This gives me more confidence that I could do more complex conversions later on.  Below are pictures I took after the new conversion, with the Sony A7.




Wednesday, July 27, 2016

Update on the Progress of the Lathe Project

I have been quite busy with other stuff lately so I haven't really spent as much time as I would have liked on learning to use the lathe.  But, so far, I have done a few small projects, mostly with positive results.  Now that I know what the lathe can do for me, it would be hard to live without one.  It is, of course, not without lots of frustration.  The learning curve is steep, especially since I had no prior experience with a lathe.  Below is a very condensed summary:
  • The 1/4 horsepower motor is not powerful enough to do quick, smooth deep cuts.  It often stalls when making what I consider reasonable thickness of cuts.  Boring a larger hole or making a parting cut could take a long time and this simply drives me crazy.  I have to remind myself that the Taig Micro Lathe was designed to make small parts and I need to be patient.
  • The lack of thread cutting capability as a default feature on this lathe is now a small annoyance.  I actually have a need to cut threads, and it's more often than I originally thought I would need.  Outfitting the Taig Micro Lathe II with thread cutting feature would mean an expensive upgrade (for me).
  • The small size of the lathe is one of the best features.  It sits on a small desk with space to spare.  That, alas, is something of an Achilles heel.  This means working with anything larger 3 inches in diameter is difficult.  Also see point #1.
  • It's hard to describe the feeling when a project is completed.  It's a feeling that should be experienced.  A sense of purpose, accomplishment, and the whole process was therapeutic. 
So far, I have used the lathe to help convert a few lenses to work on Sony E-Mount, from very simple turning of the lens barrel to actually making parts.  The pictures below shows few of the lenses I have done.  One thing I have learned, is that drilling and tapping small holes and making them aligned perfectly is no easy task without proper tools.

Three Amigos - Konica 45mm f1.8, Argus Cintagon II 48mm f2, and Minolta Rokkor-PF 45mm f2.  The Konica and Minolta lenses share the same 12-17mm focus helicoid for focus.  Both uses an M42 mount I savaged from old lenses to mount to the helicoid.  If I could cut threads, I would have no need to use old parts, because eventually, I will run out of them.  The Cintagon II modification is only partially successful.  It works, but not well.  You can see extra holes on the part that I made.  Those are mistakes :) I think I will get rid of its original focus mechanism and use a helicoid for focus instead, or converted to L39 or M mount.

In all, I really enjoy using the lathe to make lenses work better on my camera.  Hopefully my skills on using it will improve and the conversions will look and work better in the future.

Bokeh - Minolta Rokkor-PF 45mm f2 (from the AL rangefinder) & Sony A7.

Thursday, July 21, 2016

Meyer-Optik Trioplan 50mm f2.9

In case you have not heard, Meyer-Optik has crowd crowd-funded and released a "new" 50mm f2.9 Trioplan lens.  Great news for those who love the soap bubble bokeh, but you will have to shell out a cool $600.  The Trioplan is a very simple optical design based on the Cooke Triplet, and there are huge number of lenses with Triplet design in different focal lengths.  $600 is a ridiculous amount of money for a simple lens.  You can buy the same lens in the used market for a lot less.  In the mean time, a lot of alternative are available, but let's get on with the old 50mm f2.9 Trioplan.

Meyer-Optik Trioplan 50mm f2.9 & Sony A7

This lens came from a Beltica folder camera that I bought from the Trunk Sale organized by the Photographic Historical Society of Canada (PHSC) last Sunday.  The camera (lens, actually, since all the shutter/timing etc are in the lens, not the camera) still works perfectly, but I took it out (but is easy to put back in if needed) and adapted it with an M42 mount.  The lens has its own focus mechanism which is good from about 3 feet (1 meter) to infinity.  I am not a big fan of very long minimum focus distance, such as this one, so I put the lens on a Pentax focus helicoid and uses the helicoid to focus instead.  If I really want macro level close focus, I could use both the focus on lens and the helicoid, but I found that the lens' bokeh is destroyed/masked when focuses too close; all you will see is very shallow depth of field with pretty much uniformly blurred background, which to me, is boring.
Meyer-Optik Trioplan 50mm f2.9 & Sony A7

The lens is coated and looks quite nice, but still very susceptible to flare, even with a hood in place.  Care should be taken when shooting against the light.

As expected, the Trioplan 50mm f2.9 produces very similar rendering as other Triplets, but each has its own unique traits.  For comparison, I used the Balda-Werk Rigonar 50mm f3.5 quite a bit, which is also a triplet.  I much prefer the Trioplan.  Perhaps the extra 1/3 stop of light makes a bit of a difference, but I find the Trioplan much more pleasing with less harshness in the out of focus area.



Like most Triplet lenses I have used, the corners of most of them are not very good, even when stopped way down.  So this is not really a landscape kind of lens.  The center of the lens, however, is quite sharp.

I quite like shooting with this lens, especially when mounted on the butterly smooth Pentax focus helicoid.  I like the rendering of the lens, but most importantly, I didn't have to pay the exorbitant price for one.

Tuesday, June 28, 2016

First "Real" Lathe Project - Argus Cintagon II 48mm f2

My buddy Cliff got me some aluminium rounds and now I can actually do some "real" lathe project :)

The aluminium rounds came in 12-inch lengths.  I really should have them cut into 2 inch pieces, because cutting a 2.5" diameter round took almost 20 minutes with a hack saw by hand.  I originally thought that I would cut each piece to the lengths I want, so I won't waste any materials as they are quite expensive, but that does not seem like a great idea now.  In any case, the very first lens I want to make usable on my A7 is the Argus Cintagon 48mm f2 lens that came from a Argus rangefinder.

The reason I choose this lens is because it's the easiest one to do.  All it needs is a proper length of tube between a mount and the lens.  I thought it would be a piece of cake.  I just needed to bore out the piece, drill and tap the screw holes and it's done.  What could be simpler?

The pieces - Left: thin mount, middle: tube I worked on, left: the lens 

Well, it's not really hard, but it has taken far longer than I thought.  As my first time turning and facing a piece of solid metal, there were (and still are) lots of things to learn.  What tool bits to use, truing the work piece, etc.  While boring out the required space to fit the lens, the weakness of a micro lathe is quite apparent.  There is simply not much power/torque for deep cuts/turns.  Everything must be done slowly, even on soft metal like aluminium.

I am happy to say, the piece is is almost done, except I need to drill, and tap the screw holes for the tube on the side, and the mount at the back, and there is only one problem.  I don't have any small tap tools, drill bits, and a drill stand.  This whole business of lens conversion takes so many other tools and accessories that I didn't think of at first.  In any case, I ordered a Flexshaft for my Dremel 4000 from Amazon, and it came in a couple of days.  I am going to mount it on the cross-slide, somehow, and drill the holes on the side with the tube/lens mounted on the lathe chuck.  For the mount, the holes need to be drilled on the back, I think I will mount the Flexshaft on the tail-stock and hold the mount/tube with the chuck.  For all this to work, I have to make a mounting jig for the Flexshaft and secure it on the cross-slide and tail-stock.

All fitted together.  Still need to be screwed together.

It's almost impossible to buy a set of micro tap and tiny screws locally at reasonable prices, if you could find them at all.  I order a thousand pieces of M2 (two millimeter x 5mm) screws, a set of small drill bits and a set of 10 micro taps with size from M1 to M3.5, with handle for about $40 from AliExpress. The only problem is, shipping usually takes at least a month, and on top of that, Canada Post is likely going on strike next week and who know for how long.  In the mean time, I have an urge just glue this thing together until all the parts arrive :)

It's very gratifying to see all the pieces fit together and I am very glad I bought the lathe.  I think I am going to enjoy this.

Argus Cintagon II 48mm f2 Sample