Manual focus adapter problems

Nothing serious, but, on two occasions now, and with different types of adapter, I've had the flange that mates with the lens become loose from the body of the adapter. As might be expected, this results in out of focus shots, and that's the way that I have been able to identify the problem. Unfortunately this also means some spoiled images.

I now carry a small precision Phillips screwdriver that I can use to tighten the fixing screws. I guess a drop of loctite would provide a more permanent solution.

Sony NEX 6 death throes

It had been threatening for some time, with a tendency to automatically click through the menus - cured by rotating the top control wheels a few times, probably dirty contacts. Now, however, a more sinister fault has appeared the dreaded "Camera error. Turn power off then on."

Searching on the Internet this appears to be a fairly common fault and may be related to a small spring attached to the shutter mechanism. The cure would probably cost more than my battered camera is worth, but a get by fix is to switch off the Front Shutter Curtain. It clatters when used, but it works a bit.

The camera did well to survive as long as it did under adverse circumstances. I've taken many thousands of shots and it has been carried around on a bicycle, dropped and generally not looked after. The paint has long gone on the corners and the strap looks ready to snap. It did have the good sense to continue working until I had invested in a new Sony a6500.

I've enjoyed the NEX 6 immensely,  I had become tired of lugging a heavy DSLR around my neck. The NEX freed me from the volume and mass of the DSLR while it allowed me to shoot using my old film era lenses, the excellent electronic view finder enabling easy and precise focus. I have always admired the compact and beautifully made Leica rangefinders, but they were way out of my price bracket. The NEX provided a similar shooting experience and I suspect that the Sony sensor was as least as good as that fitted to the more prestigious marque!

So it has more or less died. It has served me well and I have no regrets!

NEX 6 versus Sony a6500

I was interested to see how the sensors compared in the two cameras. Was it indeed possible to cram all those extra pixels into the a6500 sensor without losing quality?

I set up a simple test. Both camera were configured for ISO1600, with no exposure compensation, and I fitted a Zuiko 50mm f1.8 lens. I know from previous testing that this lens will blow the standard Sony zoom out of the water, as far as the resolution of detail is concerned. The camera was mounted on a sturdy Manfrotto tripod and a 2 second delay selected. I focused with the lens wide open and at maximum viewfinder magnification, but the shooting took place at f8. Two shots were taken with each camera and the best selected for comparison - actually that was the difficult part as each of the two images taken by each camera looked to be pretty much identical.

I let the camera decide the exposure, choosing aperture priority.

The view is one within my untidy garage, and the lighting supplied by overhead fluorescent tubes. The door was open so there was also a touch of ambient light, but the predominant illumination came from the fluorescent tubes.

The a6500 chose to use 1/25th sec and the NEX 6 1/40th sec.  The histograms were quite different, with the NEX underexposing slightly and the a6500 getting it spot on.

I processed the RAW files using LR and the default setup without any further adjustment, creating 16 bit TIFFs in PS. Again no adjustments were made in producing JPGs from the TIFF files.

This is the overall view (not pretty)

and here are a couple of crops, first the NEX 6

then the a6500

Click on any image for an enlarged view, the crops are 100% pixels.

The a6500 is recording more detail without, in my view, incurring a greater noise penalty. Look in particular at the detail in the cloth, although that may be a result of the longer a6500 exposure.

To get a better idea of the noise performance of the two cameras I have selected a couple of crops showing less detailed areas of plain tone.

First the NEX 6

Then the a6500

The a6500 image looks cleaner to me.

Something else I should perhaps mention, the contrast detect feature on the a6500 was usable at maximum viewfinder magnification whereas it was not on the NEX 6.

You can't read too much into this simple comparison, but, for what it's worth, the a6500 sensor does appear to come out the stronger, you get both more detail and less noise. (Oh, and before you ask, the Acetone is used to make repairs to the ABS components of my caravan, ABS is dissolved in Acetone, so you can make up a repair solution using, for example, Lego bricks.)

23-5-2017

Sigma lens - Dodgy Contacts

I've had trouble with my Sigma 19 mm lens not responding when attached to my Sony mirrorless cameras. I was concerned that this was a warning of imminent failure, but, to date, cleaning the contacts has cured the problem.

I've tried cotton buds and that appeared to do the trick for a while, but after the latest episode of non response, this was not enough.

As a measure of last resort, I used the buds in conjunction with some Eclipse E2 sensor cleaning fluid. This worked, and saved me the cost of a new lens - I believe that Sigma regards these budget lenses as being disposable, and don't offer a repair service ( please correct me if that is wrong!).

Sony a6500 - First thoughts

My long suffering NEX 6 has been showing signs of age, in particular there were times when the camera would start clicking through the menu options. This I have been able to fix by switching off and rotating the control dials, so it is probably caused by dirt on the contacts. It's a very intermittent fault, and most of the time the camera is just fine, despite having taken a humengous number (39433) of shots.

So it came to pass that I decided to add an a6500 to this year's tax allowance.

First impressions, it's a bit heavier than the NEX and the grip is more ergonomically shaped and protrudes more. I'm not too keen on the extra mass, but the grip is better.

The electronic viewfinder is very good indeed, I had thought that it might be the same as that used in the NEX 6, but, combined with the extra pixels on the sensor, this does appear to be an improvement. I am finding that, with contrast detect set at minimum, I can now accurately focus using that aid and with the lower 5.9 x viewfinder  magnification. I was never fully confident of contrast detect on the NEX6, but this camera appears to have raised its game in that respect.

However the apparent increased sensitivity of the contrast detect function sometimes means that, even at the minimum setting, the focused image is a mass of colour, making composition more difficult. It would be useful if contrast detect could be switched off when not using a magnified view. I have programmed a button (C3) to allow me to quickly change the contrast detect mode, but I'm not sure if I will be making much use of it!

Then there are the menus, an overwhelming array of choices, but, for heritage lens users, the camera now appears to default to release without lens. whereas previously you would need to set that parameter.

I like the fact that you can program a button (C1 in my case) to select the focal length in use, in body stabilisation is a real boon for users of old lenses. It's early days as yet, but IS brings a real improvement to the use of heritage lenses on this camera. I've not carried out any rigorous testing, but I've used my 75-150 Pentax zoom (112-225 mm FF equivalent)  at 1/100th and obtained crisp results. It's not a panacea, if you bounce on the shutter release you will get blurred shots!

It also seems that you need to remember to change the focal length to be used with the IS system. I've inadvertently left it set at 150 mm and taken shots using a 12mm lens resulting in some motion blurred images. Of course this only applies to manual focus lenses, auto lenses automatically inform the camera of the focal length.

A further improvement is the ability to set the minimum shutter speed to be used with auto ISO, again I have programmed a button (C2) to set this. I need to do some rethinking about what those minimum values should be, now that I have IS in camera, but for static subjects, and shorter focal lengths, the previously available (NEX 6) 1/60th minimum is far too pessimistic.

Actually my needs are few, I normally shoot raw using auto ISO, and aperture priority, with the occasional descent into shutter speed priority and manual operation, so I don't need all those menus etc.

One slight negative, possibly due to my ignorance of the camera's capabilities, is the need to restore full frame magnification before shooting, whereas my NEX would jump back into shooting mode at a half press of the shutter. The manual states that this should happen with the a6500 too, but for some reason mine does not. It's probably user incompetence!

Update - a helpful chap on the DPreview forum pointed out that AF in Focus Mag. = OFF will enable the shutter release to cancel the magnification mode and jump back into shooting. I don't know if there are any drawbacks as yet, but my autofocus lenses seems to work fine with this setting.

My old lenses appear to be coping well with the increased pixel density, although the edge definition provided by my Pentax 28mm f2.8 is not great on distant views. It's fine close up, so I wonder if this is a field curvature problem?

I've now published the results of a quick test comparing the NEX 6 and a6500 at ISO1600

Revised 12-8-17

Jesmond Flint Mill

I walked from Newcastle's Freeman Hospital to Gateshead, following the valley of the Ouseburn.

Once this was a major trading route from the river Tyne northwards, the valley providing a steady incline for the horse drawn vehicles of the day. Years ago the burn was enclosed in a culvert, south of Armstrong Park, and material heaped above, so blocking off the road. You can still walk the route but it involves climbing over the substantial man made barrier that stands in the way.

I had to ask for directions as I approached the covered section and was fortunate to come across a local resident who knew all of the history of the area, and who drew my attention to the site of Jesmond Flint Mill, close to where he lives. Sadly I didn't get his name, but this information and photos are down to his kindness.

The flint mill was built to grind flint, carried as ballast by colliers on the London trade. The ground material was used in the local pottery industry, presumably including the nearby Malings factory.

Originally the mill was powered by a water wheel, supplied by a mill race dug alongside the Ouseburn to an upstream location near Jesmond Dene.

Later a stationary steam engine was installed, rumoured to have been engineered by a young George Stephenson, who was at that time employed as a colliery engineer nearby. The photo above shows the site of the mill and the plinth in the foreground might have been the engine base.

Further evidence of the mill seen in this stone wall built into the west bank of the burn.

The stone arch may have been the discharge from the water wheel.

Sony NEX 6, Pentax lenses.

Spectacles and Photography

In my late sixties I need reading glasses, but my distance vision is not too bad. How does this impinge upon my photography?

Well I find it difficult to read the control dials on the top of a camera, and data on the rear screen, without the aid of specs.

However my compact mirrorless Sony NEX 6 camera can be controlled almost exclusively from the electronic viewfinder (EVF), as that has a built in dioptre correction that enables me to see all of the necessary information without using glasses. I also find that I can manually focus using the 9.6x magnification that the camera provides through the EVF.

Moving from camera to computer screen it's a different story. I need to use glasses to clearly see what I am doing. Question is, what is the best solution overall?

I've tried bifocals and varifocals. My bifocals were setup to allow me to read at a close distance or see my computer screen, i.e. two distinct degrees of magnification. This worked well enough, but further deterioration in my eyesight has meant that I now need assistance for viewing middle distance objects, i.e. small road signs maybe 20 yards away etc.

Solution, a pair of varifocals, providing a continually variable range of magnification from close up to distant viewing.

Nothing is perfect, there are pros and cons.

They are great for reading, and using a small computer tablet, while in the car they allow me to read the Satnav clearly, and give an enlarged view of those middle distance objects. In the shops I can read the prices on the products etc. So far so good.

How about the negatives?

In order to best use the range of magnification, you need to look through different parts of the lenses. I.e. Lower down for close up and higher for distance. This involves moving your head.

They are not good for reading the large computer screens that I use for image processing. This involves far too much head movement to keep the required zone of vision in focus. Similarly they are not good for reading music, there I've enough to worry about without having to constantly adjust my line of sight! For distance vision they do provide a slightly enlarged image, but at some expense in the level of contrast and brightness. As a consequence I tend not to wear them when out and about.

The computer screen/music problem has been resolved by the purchase of a pair of specs of fixed magnification optimised for objects  18 to 24" away. They are far superior to the varifocals within their limited range of application.

Now everyone's eyes are different and what works for me won't necessarily work for you. Consult a qualified optician for advice!

Progress on new river Wear bridge, Sunderland

I missed the raising of the supporting pylon, combination of a bad cold and a horrible day!

However these two shots were taken shortly afterwards.  Look out for the heron in the foreground of the vertical format shot.

Tidal Surge Roker

A combination of a tidal surge and strong north westerly winds led to some impressive waves crashing over the pier at Roker, Sunderland. Friday 13th January 2017.

Canon 5DII Sigma 100-300 f4

Christmas Day, Alnmouth beach, Northumberland

We went for a walk around Alnmouth, it was very warm for the time of year, with occasional full sun, but a very strong south westerly wind blowing sand on the beach and spume from the waves.

Marsden Bay, late December 2016

A break in the overcast winter weather allowed me to walk from Marsden to South Shields along the north east coast. There was fabulous sunshine and a deep blue sea.

Sony NEX 6 manual focus lens.

Autumn Colour in Weardale

Shittlehope Burn, which runs into the river Wear from the north at Stanhope.

There is a circular walk from Stanhope taking in the burn and, later, the great disused Ashes quarry.

It was muddy underfoot at this time of year, and you need to hop across the burn at a couple of locations, but on a bright autumn day, a magical journey.

Work progresses on new Wear Bridge, Sunderland

Work is progressing on the new road bridge over the river Wear in Sunderland. The deck is being assembled on the south bank and pushed out across the river on temporary supports. There will be a tall pylon to carry the suspension cables, but that has as yet to be installed.

Sony NEX 6 probably Zuiko 50mm f1.8

Hadrian's Wall

The section of the wall just to the west of Housesteads is one of the most dramatic. I probably used my old Olympus 50mm f1.8 Zuiko lens for this shot, which takes in Hotbank Crags, looking east.

Photoshop - The Pen Tool

There is a variety of selection tools available within Photoshop, and they all have their area of application.

Perhaps the most difficult to use, and the most time consuming, is the pen tool, where you painstakingly draw an accurate boundary around the parts of the subject that you wish to work on.

I came upon the pen tool quite late in my PS career, but I regard it as being one of the most valuable selection methods, as it can accurately select to the nearest pixel.

You can use the pen tool in conjunction with say the Quick Selection tool, tidying up edges that have been missed, or ensuring that a straight line is indeed straight.

I normally work at either actual pixels view or one stage of  magnification above that when using the pen, in order to ensure an accurate selection.

There is a learning curve, but take heart, it's worth persevering. As with most things in PS, you can easily step back if you make a mistake.

Where do I use the pen tool?

It provides a nice clean boundary for a cutout (when you want your object surrounded by, normally, white space)

To preserve a section of an image when cloning, particularly if straight lines are involved. You pick the bit that you want to keep, and then select the inverse of your selection. Any cloning will then not impinge upon your important area.

To improve the accuracy in drawing a layer mask.

etc

26-7-16

Frogs in the pond

This is the froggy mating season, and they have been at it in my garden pond

I don't have a proper macro lens, and the only extension tubes in my possession are M42 screw thread, so my solution is to use an elderly Takumar 135mm f 3.5 lens along with an 11 mm extension tube.

Click for a bigger image.

Not bad for a lens maybe 45 years old! This is the M42 Super Multi Coated version, in production from 1971-1975.

Sony NEX 6

Snow on The Cheviots

Travelling on the top deck of the X1 express bus to Newcastle through the heights of Gateshead, you get a fabulous view of the city of Newcastle with the Cheviot Hills in the background. This promoted me to set out to capture a view of the Cheviots with some aspect of the city in the foreground.

St James Park with snow covered Cheviot Hills

I took this shot using a Sony NEX 6 camera fitted with a 500 mm Tamron SP mirror lens, giving an angle of view equivalent to a 750 mm lens. This lens has a fixed aperture of f8. A tripod would have been a good idea, but, in its absence  I used shutter speed priority and chose 1/1000th second to reduce the effect of camera shake to a minimum. With auto ISO selected the camera decided upon ISO 250.

On the full size image you can read the writing above the entrance to the football stadium, Gallowgate Stand.

Photo available from Alamy stock number FK5871

Coal Train day on the Tanfield Railway

On the coal train day they run a demonstration coal train in addition to the normal passenger service.

Photo used by the Times newspaper 29th Feb

Sony NEX 6 Samsung 35 mm f2

New Bridge over the river Wear at Sunderland

Work has started on the new road bridge over the river Wear at Sunderland.

Sony NEX 6

Using Manual Focus Lenses on Sony Mirrorless cameras

It's horrible outside, windy and raining, so I've time to kill. Just the opportunity to write about my experience of using manual focus (MF) lenses on the Sony NEX 6. I guess that all of this is transferable to the a6000, and some to other Sony mirrorless cameras.


First of all, why use a manual focus lens?

In my case I have a collection of them most of which I acquired in film camera days, but, having found them to be superior in many instances to the kit lenses supplied by Sony, I have since bought additional manual focus lenses. The emergence of the Chinese company Rokinon/Samyang now means that you can buy a quality MF lens new that will fit directly onto your Sony camera.

Then there is the consideration of cost. Cheap secondhand manual focus lenses, even those made many years ago, often provide superior image quality to the Sony zooms.

I should add that I have tried using manual focus lenses on my Canon DSLRs, but not obtained satisfactory results, as their viewfinder screens are not designed for the purpose. Live view is better, but not convenient for many purposes. Enter the Sony NEX 6 with an excellent electronic viewfinder  (EVF) and we have a game changer. It brings back fond memories of focusing with an old Pentax film camera which had a large, bright, optical viewfinder, complete with focusing aids.


What are the snags?

If your manual focus lens was made to fit a Pentax, Canon or Nikon etc camera, you will need an adapter to fit it to your Sony camera. There is an incredible range of adapters available to suit most marques, but do check that one exists before you buy. I have found that adapters costing as little as £20 are perfectly acceptable for use.

As the name suggests, manual focus means just that, no autofocus. There are times when autofocus is a real benefit, for example when trying to photograph your young children or grandchildren, but most of the time you don't need it. Buildings don't move, while cars, trains boats and planes normally follow fixed trajectories and you can pre-focus to get a sharp shot. OK planes are a bit tricky! Using a lens wide enough to get interesting shots in the street, the depth of field is usually enough to see you through in most circumstances.

I have lost some shots due to not being able to focus rapidly enough, but I have also lost shots due to auto focusing systems missing the target completely!

Then there is the aperture. Automatic cameras focus with the aperture fully wide and then stop down to the required setting immediately before shooting. You do the same with manual glass, but you have to remember to stop down before you press the trigger.

You might miss lens stabilisation, although the new Sony full frame cameras have that built into the body. I'm hoping that, should it ever appear, the replacement for the NEX 7 will have that feature.

Finally not all old lenses are entirely happy with digital sensors, and this can result in the appearance of colour fringing due to chromatic aberration (CA), or ( I am told, never seen it) occasionally edge effects.  CA can very largely be dealt with by a single key press in a raw converter like Lightroom. Again cheap, and not so cheap,  modern lenses also produce CA but often software is used to reduce or eliminate the effect. I have a very nice copy of a Canon 24-105 L lens that revels in CA.


Lenses to avoid

You need to restrict your choice to those lenses that have a manual aperture ring - most modern lenses don't as the aperture is controlled from the camera.

Cheap plastic bodied consumer grade zooms from the film era are often pretty poor, even from the major players.

You can't go too far wrong with fixed focal length lenses badged by the original camera company e.g. Minolta et al, or lenses fitted as standard by some of those companies. e.g. Zeiss. Third party lenses are more problematic, there are no doubt some very good ones about, with Tamron and Sigma probably better than average, but we are getting into murky waters here.

Old lenses might have developed faults in use, sticky apertures, tight focusing, or be infected with internal fungus growth. You need to be vigilant and reject anything that isn't as it should be. Don't be put off by external condition, if the glass is clear and everything works properly, it could be a real bargain. Your'e not buying a collectible, rather something to use and earn its keep.


Camera Settings and Use

Firstly you have to tell your camera that a manual focus lens is fitted, as otherwise the lack of electronic contacts will have it assume that there is no lens at all and it will refuse to work. On the NEX 6 you need to tell the camera to "Release w/o lens", an option in the Setup menu. This does not affect the operation of your auto focus lenses in any way, so you might as well just leave it at that setting.

There are three viable settings on the control dial for use with MF lenses: -

A - Aperture priority, you set the aperture and the camera selects the shutter speed
S - Shutter speed priority, I'll come back to that.
M - Manual, you set both the aperture and the shutter speed.

Then there is the ISO setting on the rear control wheel

I try to shoot at the lowest ISO that will give me a fast enough shutter speed to avoid camera shake.

There is an Auto ISO setting, which will choose a value to enable a shutter speed of 1/60 th second or faster. Unfortunately 1/60 th is not fast enough for many situations, while it's over generous for others. A better system would enable users to select the minimum shutter speed associated with auto ISO, but read below for more on that.

(Edit - Apparently the Sony a6300  has the ability to select the minimum shutter speed to use with Auto ISO, a very welcome improvement, how about a software upgrade Mr Sony? - Pigs might fly)

Depending upon the circumstance I therefore either use Auto ISO or I set the ISO myself.

Most of the time I use Aperture priority, and keep a weather eye on the shutter speed that the camera has selected, adjusting the ISO if necessary. I probably use this setting for 90% of my shots.

Interestingly Auto ISO enables a greater number of possible choices than the dial provides.

When I want to freeze the action, or, conversely force auto ISO to allow a slower speed,  I will occasionally select Shutter speed priority. Auto ISO then performs in a more reasonable fashion, selecting an ISO to enable that shutter speed. The problem with this selection is that it can lead to overexposure, as occasionally you need a faster shutter speed than the one that you have selected, even at the base ISO of 100.  I therefore don't leave this as my default setting.

I normally only employ the Manual setting either when using an external flash, or when I take Panoramas and need a guaranteed uniformity of exposure.

I find that the exposure provided with manual focus lenses tends to be rather less than the optimum, you normally get a usable shot, but it's often beneficial to dial in a half stop or more of over exposure. The (exposed) histogram is your friend, adjust the exposure and take another shot if necessary. Lenses vary in this regard, you have got to learn by experience, while, of course a white cat against a white wall will fool all metering systems, and you occasionally have to make quite radical adjustments.

Perfectionists might use an incident light exposure meter and set the camera accordingly, but life is too short, take a few shots, look at the histogram and adjust if necessary.


Focusing

The NEX 6 has a very good electronic view finder, enabling a 5x and almost 10x magnified view. This, coupled with full aperture focusing, generally allows a very precise focus to be obtained. The viewfinder on the a6000 does not have as many pixels, and I've not had the chance to try it, so I can't comment on that.

An alternative is the contrast detection system that the camera provides, when sharp edges show up in colour. There are three levels of contrast detection available for selection on the NEX6 and my camera is permanently set at the lowest level. Despite this, it occasionally picks out a false positive, so I much prefer to rely upon the magnified viewfinder image.

As a pensioner, my eyes are not getting any younger, but I find that the range of dioptre correction on the viewfinder eyepiece is more than sufficient for my purposes, allowing me to focus without glasses.

Do be aware that many adapters do not provide a sufficiently accurate register to allow you to use the distance scale on the lens, most providing focus beyond infinity. I guess that this is in order to enable rather slacker manufacturing tolerances and so hold the cost down. I do have some cheap Pentax bayonet adapters that provide a sufficiently accurate alignment for the shorter focal lengths - and this is very convenient, shooting a distant object you just wind the lens up to infinity on the scale  and fire away - but even they go slightly past infinity with the longer telephotos. You need to test your gear!

Using Unstabilised Lenses

Modern lenses generally have some kind of anti shake mechanism built in, while older manual focus lenses do not. I was taught to shoot at at least 1 over the effective focal length in order to have a decent chance of getting a sharp result, e.g. a 100 mm lens would require a minimum of 1/100 th second. Of course the angle of view is reduced by the crop frame Sony, effectively increasing the focal length by 1.5x, so you need to fire at 1/150 for a 100 mm lens etc. Always check to see what speed the camera is coming up with, and, if necessary,  use Shutter speed priority along with Auto ISO to ensure that you have a realistic chance of avoiding camera shake.

Being brought up with unstabilised lenses this does not bother me, and I use the techniques learned with film cameras to get sharp results. For example if you are shooting with a telephoto try to find a wall, post, or doorway etc to lean against, while you might also employ the delayed time setting on the camera so that you don't vibrate it while the shutter is released. Don't snatch at the shutter button, squeeze it gently. I rarely use a tripod, but for long telephotos you need to, while, a monopod is better than nothing.

It is relatively difficult to get sharp images with a handheld unstabilised telephoto lens, I generally take a few shots in order to increase my chances of a success.

Of course if you are considerably more affluent than me, you might just shell out for a Sony a6500, which comes with in body stabilisation.


Practice Makes Perfect

You can't reasonably expect to fit a manual focus lens and immediately start taking super sharp, perfectly exposed, photos, there's so much to remember and to do. Take heart, and persevere, with practice you will become a very slick and skillful manual focus operator!


Personal Favourites

I'm not, I hope, a "fanboy" having used a range of photo gear over time, including Rollei, Bronica, Canon, Pentax, Sony and Olympus, so I don't have any axes to grind or want to get into Canikon warfare.

The NEX is a wonderfully compact and light camera, and I see no sense in hanging large and heavy lenses onto it. I therefore tend to use a collection of Pentax and Olympus lenses that were notable in their day for their compact dimensions. Old rangefinder camera lenses would also be a worth a look, although many are out of my price range.

I have experimented with some old Canon FT lenses, but don't see any significant difference in their performance over the Pentax or Olympus glass of the same period, while they are more bulky and require a more complex adapter. If I had an arsenal of FT glass I would probably use it, but I'm more than content with my other gear.

The bargains have to be those lenses that were fitted as standard to film cameras during that era, and the popular additional lenses that most people bought to enhance their range of shooting opportunities, i.e. those lenses that were mass produced by the leading marques.

The "Standard Lens" would normally have been a 50 mm at around f1.8 (Pentax f1.7) and you can buy these very cheaply. There are also f1,4 variants that command higher prices, but they are larger and heavier and not necessarily any better at say f8 where most of your shooting is going to happen.

A 50 mm lens on a NEX 6 or a6000 is equivalent to a 75 mm lens on a full frame camera, it makes a good portrait lens, but I also find it a generally useful focal length out and about.

The next choice of our film era photographer might have been a 28 mm, at f2.8 or f3.5. There's loads of these about and they are not expensive. 28 mm was harder to get right than a 50 in days gone by, so you will probably see some distortion and CA, but nothing that would break the deal.

A 28 becomes a 42 on a Sony NEX, which is a very useful general purpose focal length. It's my fitment of choice as I leave the house.

The next buy for many photographers in the past would have been a 135mm lens, but this is becoming 202 mm on the NEX, and not abundantly useful.

Both Pentax and Olympus made 75-150 f4 zooms however and they provide a more practical solution. They're both sharp, but the Olympus design lacks contrast and I prefer the Pentax. A 2x zoom at this focal length range was not too much of a challenge at that period, so the lens is more than OK. I bought a Pentax 75-150 new for around £75 many years ago, but, much more recently, picked up a pristine example for less than £20.

Very wide is much more of a problem. Wider tends to be harder to get right, and I would be tempted to steer you in the direction of a new Samyang/Rokinon lens rather than an antique. Voigtländer (Cosina) make some very nice lenses, but you need deep pockets to be able to afford them.

Last edit 28-01-2017