That which we call a Canon, with any other lens

Warning: this is going to be boring. It’s about comparing lenses, so the shots are all of the same thing and therefor rather dull from an aesthetic point of view. It can’t be helped; scientific evaluation requires elimination or compensation for known variables so that the results show specific differences for the aspect being studied.

The lens adapter finally arrived, and now it’s time to put the old Pentax M42 screw mount lenses on the new Canon EOS camera and see the results. The mount itself is a Neewer M42-EOS; a simple black metal ring that does the job, but could stand to be a tad thicker for purposes of gripping to get it off and on the camera. I put it on and then use the body as a ‘Pentax’, screwing the lenses on and off as required. Someone else might spring the $17+ per lens and use the bayonet mount, but not me. At least not before evaluating the lenses.

First of all, a list of the lenses to be tried: Pentax Super Takumar 28mm f3.5, Super Takumar 35mm f2, Super Takumar 50mm f1.4, Vivitar 135mm f2.8, and Soligor 85mm-205mm f3.8 macro zoom.


Second, an explanation that preliminary testing was done before setting up the actual evaluation shots. Think of it as the anecdotal evidence that spurred the scientific investigation. I knew these lenses to be very good from the results I had when shooting with film, something I haven’t done for about 15 years now. Also I had to try out the mount and see how easy/hard it was to change lenses and functions. For example these are old, manual lenses for a different type of camera altogether: there’s no autofocus and definitely no communication with the exposure system. As such the camera has to be operated on ‘Manual’ with exposure determined by a little experimentation. Fortunately the T100 is just the camera to do this with and I’ve already done some “guesswork” exposure shots so I should be able to get values set reasonably close. All photos will be at the same aperture/shutter/ISO/white balance to keep things as even as possible (ran into a problem with this plan on the Soligor lens). All shot from the same location on a tripod, so the variations in field of view are strictly according to the lens. We begin with the default Canon 18mm-55mm wide and full telephoto shots as the baseline. Exposure is ISO 100, 1/250 @ f8 on all shots (except for with the Soligor lens).



Super Takumar 28mm f3.5


This is a beautiful lens. In theory it should be the same as the Canon’s widest setting, but clearly it isn’t; the Canon is wider. Never mind, the Takumar is sharper and has better contrast. (There are factors which can cause this such as quality of the glass and coatings.) I can see myself using this often for landscape views. Handily it also takes the 58mm filters that the Canon lens uses.

Super Takumar 35mm f2


What the hell happened here? I don’t know. The image appeared yellowish in the finder, even with the UV filter off. Perhaps this lens hasn’t aged well and the coating has discoloured. I will look into it further. It’s a shame because in the full size image you can see that the 35mm is like the 28mm; very sharp and crisp. You can bet I’m going to try and colour-correct this.

Edit: reshot with the 35mm, this time colour is normal. I have no explanation except perhaps I twisted the aperture ring down too far the first time, resulting in underexposure which the camera tried to compensate for. This looks much more normal, similar to the 50mm but slightly sharper to my eye.


Super Takumar 50mm f1.4


The 50mm is sharp enough, but a bit ‘flat’ compared to the 28mm and 35mm lenses. This is possibly due to some sacrifices in designing what was a very ‘fast’ lens in its day at f1.4. I probably won’t be swapping this on often as it doesn’t offer much advantage over the standard lens in any way.

Vivitar 135mm f2.8


Although slightly soft (and I realize the sharpness characteristics do not show up well on the reduced-size images), the contrast on the Vivitar is quite good. It is also a nice “medium length” lens for getting just a bit closer to nature with. I don’t think I’d want to use it for taking pictures of bears, though, as it would be a bad idea to be that close to them.  I’ll continue to use the Nikon’s extreme zoom for that job.

Soligor 85mm-205mm f3.8 macro zoom


Predictably, this lens presented the most problems. For one thing it is too big and heavy to safely balance off the camera on the tripod, so I had to ‘cheat’ and support it a bit by hand lest the whole rig sag nose-down into the ground (which it tried to). Then there was the big problem of a lack of stop-down switch, which left me with wide-open aperture only. Somewhat disappointing as the macro function on this lens is quite an asset.

The first shot at 80mm is definitely soft and lacking contrast. It is sharper zoomed out to 205mm in the second image, but unsurprisingly the contrast does not improve. It’s not a bad lens, it’s just up against tough competition. Notice these two macro shots, the first at 80mm (physically closer for focus range) and the second at 205mm:


Keep in mind this is wide open aperture; if I could have stopped down no doubt the results would have been sharper and the exposure more accurate (I had to adjust shutter speed up to compensate for going from f8 to f3.5 and I’m not sure I got it close enough). Although the macro function is great, I don’t think I’ll be using this lens much for anything as there are too many drawbacks (specifically the aperture problem).


I’m pleased, disappointed, and somewhat confused by some of the results with the old lenses (especially the 35mm being so yellow). Nevertheless there is great potential here, as soon as I figure out what it is. Certainly the 28mm and 135mm show promise. Also there is the fact that I can get and use further M42 lenses (oh how many I gave away last year!) if I see one I fancy.

The Canon T100 is proving to be a great camera for experimenting with, and I’ve only just begun to experiment really. I think I’ve got its operation under control and now it’s time to turn my creativity loose, as soon as life will let me.

Oh and your suspicions are correct: I have ordered more accessories to play with.

Addendum: one thing I didn’t mention is that the Canon has an overhang above the lens caused by the built-in flash unit. This does a fairly effective job of blocking the view of the aperture ring on these lenses. You have to look at it from an angle off to the side. A minor but annoying inconvenience.

2 thoughts on “That which we call a Canon, with any other lens

  1. Marc, the adapters available these days offer such a wealth of options with old lenses. As far as I’m aware, Canon EOS mount cameras are the most adaptable as they have a wide “throat” and can accommodate other mounts that are narrower.

    I used some C/Y (Contax/Yashica) lenses on a film EOS and they gave great results. The Yashica ML lenses are excellent and more affordable than many vintage lenses.

    M42, as you know, offers a massive range of options. You’ve gathered together some excellent ones, I’m a big fan of Takumars.

    Your comment about the Tak 28mm – “In theory it should be the same as the Canon’s widest setting, but clearly it isn’t; the Canon is wider”. This is because both lenses have the focal length marked in 35mm equivalent terms. The 28mm is 28mm on a 35mm camera. The Canon has I expect an APS-C sensor with a 1.6x crop factor. This means your 18-55mm zoom at 18mm is an equivalent field of view (ie how much of the scene it captures) of 18 x 1.6 = 28.8mm, in 35mm film terms.

    The Tak 28mm,on an EOS with a 1.6x crop factor gives a field of view of 44.8mm. Which is actually a great “normal” field of view. Anyway, this is why there’s a lot more in the photograph taken with the 18-55mm at 18mm compared with the Tak 28mm – 28.8mm is significantly wider than 44.8mm.

    I’m sure you’ll continue to find that despite their performance and reputation shooting film, some M42 lenses just seem to work better on APS-C digital than others. I had a couple of 35/3.5 Taks that I had high hopes for, but were both just really bland and disappointing on a Pentax DSLR. But a 55/1.8 Tak is excellent, as it my 35/2.4 Zeiss Flektogon.

    Look forward to hearing about more experiments in the future!

    Liked by 1 person

    1. I specifically went with the Canon for the reason you mention; its adaptability. Some of the reports of using the old lenses with, say, Nikon were disappointing; inaccurate focusing, many lenses too long in the back to fit, etc.
      I’ve still got some extension tube to try out, but I probably won’t be buying anything new (or used) for a while yet.


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