Hello I'm Graham and I hope everyone's having a great day welcome to today's
video which is a presentation on the pros and cons of using legacy lenses on
the Canon EOS m 50 camera. now the m50 is a beautiful camera for shooting stills
and 4k video now quite a lot of critics of the m50 criticized the crop factor
that's been applied to the video especially if you shooting in 4k mode
but for some instances if you're a long-life photographer or videographer
that extra crop can be beneficial so it depends whether your landscapes
videographer I'm on that wide Vista or you're a one line photographer and want
that extra reach that the extra crop factor gives you now I fall into the
latter category I want the extra reach that the crop
factor gives me now we're going to discuss the merits of using some of the
old film camera lenses on the m54 video now it's different if you're gonna
be shooting stills were the high resolution requirements of the modern
sensor may be beyond the realization of the film camera lenses if you're
shooting 4k video again that resolution isn't quite as severe as you need for
stills and again if you're shooting 1080p you can get away with some fairly
low resolution lenses as that requirement for shooting video is very
low so I'm going to be discussing lenses which I find a suitable for shooting 4k
video no the lens system I've chosen to use is the pentax k mount you can use
any of the aps-c modes providing that the lens flange back distance can be
accommodated by a suitable packing adaptor between the lens flange of the
camera and your lens flange of your legacy lens so the k mounts only needed
a 2 millimeter thickness between the PK lens and the EF 2 ESM Canon adapter now
you can get a one-piece adapter this goes from Pentax K down to EOS m but I
just decided to use a ringing I didn't want the etic complexes
they have used an additional adapter so this little ring between the lens itself
and the EF TSM adapter is always required to give me the Infinity focus
of this lens now remember we are talking using fully manual lenses so focuses
manual and the aperture control is manual no way of controlling either
those from the camera as there's no system to communicate from the processes
in the camera to the lens itself but that's not really a bad thing it does
teach you how to use a camera correctly in a manual stills or video production
now what I'm talking about video production I'm talking about amateur
methods here I'm not talking about fully professional methods where you're going
to be using much more sophisticated lens set ups than you're gonna get with these
simple manual lenses one of the reasons I suggest that is if you're using these
manual lenses you may notice what's called focus breathing so as you're
changing focus position within a shot you may see that the actual outside
periphery of your frame is moving as well and that's called breathing so that
could be disturbingly shooting in a professional mode but for most amateurs
it wouldn't be noticed and it's probably inconsequential now with the legacy
lenses these were designed for a film based system and the film itself had a
matte surface so when the film was running in the back of the camera and
light was shining through the lens onto that film during the exposure there was
very little reflection from that matte surface back to the final element of the
lens itself so reflections weren't really a consideration but now with a
modern digital camera at that sensor it's got a highly polished surface and
lens reflection becomes an issue some of these older legacy lenses have got a
plane or convex final element so light coming through the lens being reflected
off the sensor back to this plane surface here is reflected back down to
the surface of the sensor so you get either hot spots or a reduction in
contrast not a lot you can do about that you can just test your lens and if it's
fine you've got a good winner there if you've got these hot spots there's not
one force much you can do to eliminate that
problem some of the more recent unlock lenses if you want to call them that
I've got a convex lens at the back and you don't get as much reflection now
another issue you may come across when you're using wide-angle lenses is the
fact that with these digital sensors each of the pixels has its own like
covering lens and then sort of a light gathering tube which takes the light
from that lens down to the center itself so the angle of incidence of light rays
needs to be fairly tight to the lens axis with these wider angle lenses
especially the film lenses are been designed for digital systems those
arrays are quite obtuse and you start to get a little more vignette engaging of
your image so if you're shooting with a wide-angle lens and you see you've got
big missing if you can't correct for that in Photoshop then again the lens
probably isn't going to be used in a digital environment I just mentioned a
big netting with digital lenses you can profile that into the JPEG processing
system within the camera and you get automatic correction for vignette and
lens distortions with using a manual system obviously the camera doesn't know
what lens have been attached so you've got no correction for big netting or
barrel or pincushion distortion so you're going to have to correct that in
post-processing might be a bit of a pain if you're shooting video but obviously
easier if you're shooting stills
with these lenses most of them were designed for full frame systems so you
are going to be talking about a crop factor of 1.7 of the camera self plus
the additional crop when you're shooting 4k so something like this 50 millimeter
lens will be something like 85 millimeters of our shooting stills and
something like a hundred and five millimeters if I'm shooting video now
that could be about an advantage if you're shooting video if you use in
wildlife or it could be a disadvantage if you using it for wider shots ideal
for portraits of using it instills mode you've got a nice 85 millimeter F one
point seven light gathering capabilities so again some nice low-light shots an
equivalent of about F 2.2 2.4 sand like that in terms of equivalent depth of
field from a 35 millimeter lens so 50 millimeter F one point seven lens is an
ideal portrait lens adapted on this camera with these zoom lenses the only
way you can correct for the changing light as you zoom and you lose in
aperture from F 3.5 to F five point six is in the semi-automatic mode that the
camera will take and that will adjust either the shutter speed or the ISO to
correct for the change in light so bear that in mind of using these lenses in
the fully manual mode where you set the ISO and the shutter speed to the amount
of light coming through your lens of whatever aperture you've got if you zoom
with the lens then you will see a change of exposure because the camera won't
correct for that if you're shooting in that fully manual mode if you have the
camera set to the semi-automatic mode rather than the fully manual mode then
obviously the camera will correct for the change in exposure by either
changing the shutter speed or changing the ISO too much that looking at this
particular adapter I just dismount the lens you can see we've got here on the
back the three millimeter lens flange adapter which makes the lens flange back
distance from the lens to the sensor correct for this particular lens and it
does give me in finiti focus you can use the embody
stabilization of the camera to correct for the fact that you've got no lens
stabilization so you've got the digital stabilization and enhanced digital
stabilization if you're prepared to put up with some of the rolling shutter
effects if you're going to be hand holding the camera if you've got it on a
tripod then the extra crop if you're using it for wildlife is again an
advantage to you but if you're hand holding this you do suffer from the
rolling shutter effect as the image moves around on the sensor and iPhone
the quality of these piqué lens is superb especially this 50 millimeter
it's really sharp even at F 1.7 from Center to edge because of the extra crop
of the full frame lens used on the aps-c sensor so that gives you that advantage
so let's look at some practical examples that I shot today using these two lenses
at Liverpool castle which is built as a replica ruin off the real prolific bull
castle built on the site of Louisville waterworks reservoirs at Rivington
so some close-ups and some wine angle telephoto shots just to give you an idea
of the quality of these lenses and ones that they would be suitable for your
application your stills all your video productions well we're here at the
replica ruins of Louisville castle built by Liverpool corporation some years ago
and it's on the banks of the reservoir which actually feeds Liverpool itself
so here to test the quality of the Pentax lenses mounted on the canon eos m
50 body we're using the standard EF 2 es m adapter and then a PK 2 EOS adapter
which screws onto the front of that particular adapter mark we're using a 28
millimeter setting capitis a 3.5 and my shutter speed is about a three hundred
and twentieth of a second now ideally I should be using a shutter speed which is
roughly twice a frame rate so I should be using about a 50th of a second but
unfortunately haven't got the right step-up ring to adapt my variable ND
filter down to 58 millimeter so I can only use that on the Pentax 50
millimeter lens that will be tested next I'm roughly about three metres away from
the camera so you can see the amount of crop we get using the adapted lens on
the body first of all we've got the 1.6 times crop of the full frame lens to
consider and then we've got another one point seven times crop when we're using
4k video so we've got quite a severe crop now in introduction I said that
could be a disadvantage if you're shooting wide-angle shots but if you're
a wildlife shooter you get in that extra focal length which is all important when
you're shooting small birds and small animals okay let's now test this at
different apertures at the moment we're at 3.5 let's have a look at it at 5.6
f/8 and f/11 just to see the sharpness on this brick wall behind me I've now
got the aperture set to f/8 and now the aperture is f11 I'm going to go in for a
close-up shot I can see a small flower growing in that window there so I'm
going to try and get a close-up shot of that particular flower well at the
moment I'm using an aperture of f/4 5.6 and my shutter speed is currently one
fiftieth of a second which is twice a frame rate so that is the suggested
speed of the shutter to give you that cinematic look but in the wind that's
blowing and that flower is moving about we might be seeing some motion blur so
I'm going to open up the lens f 3.5 so I can get a faster shutter
speed which should reduce some of that motion blur so now that is with the
aperture F 3.4 leave the shutter speed has gone up to 1/100 of a second but you
can probably notice a little bit of blooming around that flower itself so
the lens is given a little bit of reflection bike which is causing that
little bit of blooming which you didn't see at a smaller aperture of F 5 point 6
the lens is currently set to 18 millimeters which has given us something
like 115 120 millimeters effective focal length before we apply the 1.7 x factor
of the 4k video so I'm shooting it at about 18 inches away from the flower
itself I'm using f4 and I moved a little bit closer again I used a little bit of
exposure compensation here of minus one because of the darkness of the
background causing the Flint to overexpose and again the exposure is
we're using aperture f/8 and the shutter speed was about a 50th of a second so
the ISO in the shot is ISO 320 just a sweeter thirtieth of a second and up Joe
is f/8 so this is a shot of Rivington moorland you can see Rivington Pike on
left-hand side which is one of the beacons used to warn of the approach of
the Spanish Armada I believe and behind that is the Winter Hill television
transmitter and because of the brightness of the sky I've got plus 2/3
of an AV dialed in so that's it for this video I hope you found that useful if
you are a new viewer please do click the subscribe button and the Bell
notification icon and you'll be notified when I upload new videos to any of this
series also check out my photographic blog and I'm going to put a link to that
in the video description below on that video blog you'll find lots more
information on camera systems the Micro Four Thirds system aps-c systems the
canon eos m and panasonic lumix bridge cameras also check out the invitation
there too during the monthly three-to-one also on
the homepage is the application form there to join my newsletter group and
that's a newsletter that's published every three weeks it's more than news
it's almost a technical publication in its own right on camera systems and
anything photographic that takes my fancy as I work through that three-week
period so that's so for the video hope you do find that useful as usual thanks
again for watching please do take care and I hope to see you all in the next
one good bye for now
you