Are Celitic lenses really that bad?

Discussion in 'Sony/Minolta' started by jon_sak, Jun 28, 2005.

  1. I recenlty aquired a 28mm f2.8 celtic lens and I can't see any differnce between its performance when compared to the older MC lenses and the later MD lenses. I do however see that the rokkor-x 28mm is a tad sharper. Outside of flare I don't think the celtic 28mm are all that bad. As for the zooms I don't know for sure, but I can say the 28mm is pretty good.
     
  2. Their main drawback is that the resale value is significantly less than for a Rokkor lens, but as long as you get them for a good price, I see no reason to avoid them. Eshewing Celtics is a snob thing ;-)
     
  3. Celitics have more edge illumination falloff at the fastest fstops; than Rokkors. With slide film; this is more noticeable.
     
  4. Some of the Celtic lenses are of the same optical design as the rokkors (I do not know which ones). The main differences lie in the lens coatings and the materials used. chad
     
  5. My understanding is that ALL celtics were new designs; a value line of lens. Most of the lese reports for them were in the late 1970's; and decent. Several reviewers mentioned the light falloff being worse at the edges; than Rokkors; and the faster 2 f stops. The mounts were a lighter duty too. Remember these were brought out when there was a major downsizeing in camera design for size and weight; and computer lens design was alot cheaper to do of tolerancing. The Celtics were a new lens line; designed sometimes many years after some of the older existing rokkors. Thus in some cases a Celtic can be a more trick design than an older rokkor. In Nikon; there was the E series of Economy lenses; with the same design goals.
     
  6. I used to use a Minolta Celtic 135mm f/3.5 MC frequently. The results were perfectly fine, though I often wished for something faster. But who doesn't?
     
  7. My understanding is that ALL celtics were new designs That is true in that all Celtic lenses differ in some features from their Rokkor counterpart, but it is not true that they always have a different optical construction. In some Celtic lenses only the coatings and the label seem to differ from their Rokkor counterpart - of course the marketing department would not hesitate to call this a "new design ;-) The only lens I have ever owned in Celtic and Rokkor version at the same time is the 100-200mm f5.6 - admittedly not a stellar performer in either version. However, from all I could tell it was the same lens, and I was not able to distinguish from the pictures between the difference in coatings. At any rate, both have a 8 elements in 5 groups optical construction. The 28mm f2.8, which this thread is about, has a 7 elements in 7 groups optical construction, in both the Rokkor and Celtic version. Only the late style MD version without the Rokkor designation differs, and has 5 elements in 5 groups.
     
  8. The MC Celtic 28/2.8 and first MD Celtic 28/2.8 have the same optical design as the late MC W. Rokkor-X 28/2.8 and 1st generation MD Rokkor-X 28/2.8 lenses: the 7 elements in each lens have the same profiles and arrangements. For the 28/2.8's, these four lenses share the same bodies. The MC Celtic 28/2.8 was a concurrent (not "new") design alongside the then-new MC W. Rokkor-X 28/2.8 from around 1973. I believe the only differences lie in the coatings.
     
  9. I have 50mm f/3.5 MC Celtic macro lens. From what I have been able to tell it has the same optical design as the Rokkor but the cosmetics of the barrel look different. Nikon, Konica, Pentax and Yashica sold less expensive lens lines but a fixed focal length macro lens was never included. Only Minolta did this. For the record, the Celtic macro lens performs very well.
     
  10. Unless you worked for the lens design group; one would never know if they were a different design or not. The classical Tessar loooks the same after 100 years; but there have been thousand of variants; by dozens of makers; with the same appearing optical diagram. The library of lens glasses has increased each decade. A lens can be improved with higher index; high cost glass; and the design can have the same optical diagram for the marketing chaps; same lens groupings; just different glass. The optical barrels can be better in the premium lens line; bores better toleranced; for less tilt and less shifts in centration. Several of the lens test reports in the 1970's mentioned more vignetting with the Celtics than Rokkors. Vignetting is often a lens design tradeoff to squash pesky edge rays some; to get the imagery up; with some loss of illumination.
     
  11. In the later 1970's in the midwest; KMART sold Celtics ; and the Rokkors were at the camera shops.
     
  12. Camera makers tried to 'counter-actack' the price advantage of independant lens makers (mostly Vivitar, Tokina, Sigma and Tamron) by making a cheaper 'value line'. Among these, Nikon series E have the best reputation and Minolta Celtic probably the worst. That said, any fixed focal lens within 28mm and 200mm will perform fine at reasonnable apertures (here F5.6 to F11) but to one aspect : flare and related contrast. As for zoom, i would trust only a moderate one (like 70-150mm F3.5 or F4) So, are these worth having ? Yes if you are on a low budget or if that specific focal is very secondary in your arsenal (you use it little) and, of course, if found very cheap. I will add that in today's used market, a higher end 28mm or 135mm (like Rokkor but not Zeiss or Leica) is very afordable since 24mm and zoom are more popular. Also, 'third brand names' (mostly the big 4 but also Kiron and some forgotten) could be better buys than Celtics. Finally, flare is one of the important aspects to consider with a wide angle and not to be neglected.
     
  13. I personally would dispute the bad reputation of the Celtics, and the better reputation of the Nikon Series E. IMHO, both of these series optics were comparable to the main brand, the question was, how much down-spec'd was the mechanical construction. Having owned a couple of Celtic lenses (135mm f2.8 and 28mm f2.8) for many years, it's my view that they were closer to the Rokkor lenses in mechanics than the Nikon Series E was to the Nikkors. I always thought that the images from those two Celtic primes were indistinguishable from the Rokkors, and mechanically, they were not too far down either.
     
  14. It is unlikely that Minolta would have spent the time, money and effort designing a whole new 50mm macro lens. I also have a 50mm f/3.5 Rokkor-X bellows lens. This lens is supposed to be optically the same as the Rokkor with the focusing mount. I have not seen any difference in performance between this lens and the Celtic. Yesterday I got a 50mm f/1.8 AIS Nikkor from an eBay seller. As far as I know this is the last version of the non-AF 50mm f/1.8 lens Nikon made. The test shots I did today show that it is decently sharp. Mechanically it seems quite cheaply made. The infinity focus is off and as you turn the focusing ring the image moves slightly from side to side. This would be a sign that the lubrication needs to be redone or that the helical mount is worn. To add insult to injury the lens has no prong. Now I will have to add an FT3 to my Nikkormat collection. This lens reminds me of the 40mm f/1.8 Konica Hexanon lens which was sold in kit form with the ill fated FS-1. It is a very sharp lens but mechanically it leaves much to be desired. The 50mm f/1.8 AIS Nikkor is supposed to be based on the design of the E series lens. That one must have been really cheaply made. Konica made three Hexar lenses in AR mount. There was a 28mm f/3.5, a 135mm f/3.5 and a 200mm f/4. The 28 and 135 lenses are not the same as their Hexanon counterparts. The 200 is optically the same as the Hexanon but it comes, oddly enough, in a much larger barrel. Some of the independent lenses were opticaly excellent but mechanically mediocre. I would include the following lenses in that group: 28mm f/2 Vivitar Fixed Mount, 28mm f/2.5 Vivitar Fixed Mount, 35mm f/1.9 Vivitar Fixed Mount, 135mm f/2.8 Vivitar Fixed Mount, 135mm f/2.8 Vivitar Close Focusing Fixed Mount. The Kiron fixed focal length lenses seem not only optically good but mechanically better than the Vivitars. This is true even though Kino made some of the same focal lengths/speeds for Vivitar. The Vivitar Series 1 fixed focal length lenses and the heavier shiny fast Soligor C/D lenses were built more sturdily but were more expensive and did not all sell so well. By the late 1970s many camera manufacturers started to make cheaper lenses even if they didn't have separate lens lines. At the same time that Nikon was making its flimsy 50mm f/1.8 AIS, Canon had a 50mm f/1.8 New FD with only 5 blades and not very sturdy construction. Minolta's 50mm f/1.7 MD didn't look very sturdy compred to the older MD Rokkor-X but internally it was made well and was very sharp. Konica went from a sturdy 50mm f/1.7 to a more flimsy looking 50mm f/1.8 and there was even a plastic barreled version of this lens for foreign markets. By now prices on many manual focus lenses are so low that getting a Celtic or E series or Yashikor or Hexar doesn't save that much. I have a 35mm f/2.8 MD Celtic which I find to be very good and the three Hexars I have are all decent performers. Mechanically they are not up to the Hexanon standard.
     
  15. I disagree about the older Vivitar 28mm f2.5 lens. I've owned it in 4 or 5 different mounts over the years. It's built like a tank, and I've NEVER had one go bad in any way, even though most of them are 30-35 years old. It's also a heavy enough hunk of metal and glass to make a formidable projectile and VERY sharp. It's only optical shortcoming is, it's susceptible to flare wide-open. It's MUCH better constructed, say, than the Kiron/Vivitar 28mm f2.0, which has a reputation of having the diaphragms go bad. It can also be easily found for sub $20 at used camera shows and on ebay (it typically sells for low teens plus shipping on the bay, and at that price, makes a great starter wideangle).
     
  16. I think you misunderstood me. I love the 28mm f/2.5 Vivitar Fixed Mount lens. I have it in the following mounts: Konica AR, Minolta SR, Canon FD, Pentax screw and Olympus OM. It is one of the sharpest 28mm lenses I have owned. I would like to find one in Pentax K mount and one in Nikon F mount. Last summer I shot part of a wedding with it and the results were excellent. If I compare the lens mechanically to my 28mm f/1.8 UC Hexanon or 28mm f/2.5 Minolta MC or 28mm f/3.5 Canon FD it is not quite up to those standards but it is very sharp and still reasonably sturdy. In 1972 I bought a second lens for my Konica Autoreflex T2. I was traveling with my parents and brothers in Europe and did not know much about cameras and lenses yet. I wound up buying a Chinon brand 28mm f/2.8 lens. It was a dog. A year or two later I replaced it with a 28mm f/2.5 Vivitar and the improvement was tremendous. When I had more money I eventually traded both the 28mm f/2.5 Vivitar and a 20mm f/3.8 Vivitar for a 24mm f/2.8 (first version) Konica Hexanon. I missed those two lenses and years later when I began to collect I found examples of them again. I also have 20mm f/3.8 Vivitar lenses in Minolta SR and Pentax screw mounts. Some years later Vivitar came out with the TX lenses (replacements for the T4 series) and they sold a 28mm f/2.5 model with interchangeable mounts. It is also a good lens but I like the older f/2.5 model better. It is true that many of the 28mm f/2 and 24mm f/2 Vivitar lenses have sticky diaphragms. These can be repaired. The Kiron versions seem less prone to this problem. I wish photo.net had a Vivitar forum.
     
  17. I don't know what there was to misunderstand. You included the Vivitar 28mm f2.5 in a list of 3rd party lenses that you considered to be optically excellent but mechanically mediocre. I merely stated that I thought that Vivitar 28mm f2.5 was FAR better than mediocre mechanically, as well as being a fine optical performer. IMHO, it's one of the best-constructed 3rd party lenses from the circa 1970s timeframe. I think it's as well made and substantial an optic as the Series One lenses were.
     
  18. The 28mm f/2.5 Vivitar Fixed Mount is a very nice lens indeed. I forgot to mention that I also have a pre-set T-mount version. The following Vivitar Series 1 lenses are in my collection: 28mm f1.9 in M42 mount, 90mm f/2.5 w/1:1 adapter in FD mount, 135mm f/2.3 K/AR, 200mm f/3 K/AR, 200mm f/3 M42, 35-85mm f/2.8 M42, 28-90mm f/2.8-3.5 OM, 28-105mm f/2.8-3.8 FD (2 of these) and 90-180mm f/4.5 K/AR. I would say that the 28mm f/1.9 Series 1 lens is more sturdy than the 28mm f/2.5 Fixed Mount but perhaps including the Fixed Mount lens in the mechanically mediocre category was a bit too harsh. The first version of the Fixed Mount lens in Konica AR mount had a screw to hold in the spring for the EE lock button. It would sometimes come loose, releasing the spring. Later models had a cap without a screw head and that worked better. My first SLR was a Konica. If I did not use a flash I usually kept the aperture ring locked to EE (later AE). If I had to make small exposure adjustments I would tilt the camera up or down and lock the meter reading before recomposing. Years later when I began to collect and use other SLR makes I saw that some lenses had smoother aperture rings than others. Of the lenses in my collection some of the smoothest aperture rings are on the Canon FL models. I now have some Nikkor lenses with smooth aperture rings too.
     
  19. Well, since I've never had the Vivitar 28mm f2.5 lens in Konica mount, I'll have to concede that perhaps that mount was not so well made. But I've had the lens in Nikon F (which I AI converted), Minolta MC, Pentax M42 and K, and Canon FD - and these were all built like tanks.
     
  20. I have the vivitar 28mm f2.5 in M42 which was made by Kiron. It is sharp and well made. I use it for weddings and have made 12 by 16 inch enlargements which are sharp. hugh
     
  21. My 28mm f2.8 MD Celtic seems fine to me so far, though I haven't thoroughly tested it yet, especially for flare. Mechanically it seems a little less heavily built than my Rokkors, but still well done. I'll be testing a 135mm f3.5 MD Celtic soon, too. I don't expect that with such a relatively simple lens as the 135mm that there's much difference between the Rokkors and the Celtics, mainly mechanical and cosmetic variations and possibly the coatings. From what information I've been able to gather the optical formulas are the same. As far as the Vivitar 28mm f2.5, I've got one too, in TX mount for Konica AR-it's built like a tank (probably by Tokina; all the Tokinas I have are heavily built, very tough), and is generally sharp too, though again I haven't challenged it for flare or wide open. It was probably made in about 1976, so I doubt that it's multi-coated and is probably pretty flare-prone if pushed. But then it cost about $10 plus shipping, so who's complaining..!?
     

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