All teleconverters degrade the image to some extent, 2x more than 1.4x. In film & 6Mp days cropping wasn't really an option so they did give more reach without the expense of a longer lens. Long ago I had an M42 Vivitar 2x which made my SuperTak 55/2 a useful 110/4. Given a high quality TC and a fast host lens, good results are possible. However with the high Mp sensors now in common use, a cropped image without the TC may be just as good or even better so what is the point? Only perhaps cropping options of the TC image which starts with full Mp? Alan C

The short answer is no they're not a scam.  However, most TCs will magnify any shortcomings in the system they are added to. Cheap TCs come with their own sets of optical problems and failings, but a good one, or a matched TC will give good enough results, for a price.  The problem is as time goes on you often don't get what you pay for.  I played around with a number of TCs inexpensive and in some cases very expensive during and after the film era and the only ones that really were worth while that I used, were the Pentax 1.7 AF adapter, not strictly a TC but it works as one on lenses up to the * 300mm f4.0 twins, with decent results.  Though neither of those lenses is the most optically stellar Pentax telephotos.  The Vivitar 2x Macro focusing TC worked very well with shorter focal lengths say between 40mm and 100mm, especially on film, on digital it was a little less useful and the images sometimes left a bit to be desired.  The Vivitar 70-150mm with it's matched multiplier gave results that were very close to the lens alone, unfortunately that lens was subject to an incredible amount of veiling flair so unless the photo gods were smiling the results were pretty poor most of the time. On 7/16/2021 5:00 AM, Alan C wrote: > All teleconverters degrade the image to some extent, 2x more than > 1.4x. In film & 6Mp days cropping wasn't really an option so they did > give more reach without the expense of a longer lens. Long ago I had > an M42 Vivitar 2x which made my SuperTak 55/2 a useful 110/4. Given a > high quality TC and a fast host lens, good results are possible. > However with the high Mp sensors now in common use, a cropped image > without the TC may be just as good or even better so what is the > point? Only perhaps cropping options of the TC image which starts with > full Mp? > > Alan C > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and > follow the directions. -- America wasn't founded so that we could all be better. America was founded so we could all be anything we damn well please. - P.J. O'Rourke -- This email has been checked for viruses by AVG. https://www.avg.com

Most of my bird photos are shot with the DA 1.4x. Excellent glass, Paul > On Jul 16, 2021, at 1:55 PM, P. J. Alling <webstertwentysix@gmail.com> wrote: > > The short answer is no they're not a scam. However, most TCs will magnify any shortcomings in the system they are added to. Cheap TCs come with their own sets of optical problems and failings, but a good one, or a matched TC will give good enough results, for a price. The problem is as time goes on you often don't get what you pay for. I played around with a number of TCs inexpensive and in some cases very expensive during and after the film era and the only ones that really were worth while that I used, were the Pentax 1.7 AF adapter, not strictly a TC but it works as one on lenses up to the * 300mm f4.0 twins, with decent results. Though neither of those lenses is the most optically stellar Pentax telephotos. The Vivitar 2x Macro focusing TC worked very well with shorter focal lengths say between 40mm and 100mm, especially on film, on digital it was a little less useful and the images sometimes left a bit to be desired. The Vivitar 70-150mm with it's matched multiplier gave results that were very close to the lens alone, unfortunately that lens was subject to an incredible amount of veiling flair so unless the photo gods were smiling the results were pretty poor most of the time. > >> On 7/16/2021 5:00 AM, Alan C wrote: >> All teleconverters degrade the image to some extent, 2x more than 1.4x. In film & 6Mp days cropping wasn't really an option so they did give more reach without the expense of a longer lens. Long ago I had an M42 Vivitar 2x which made my SuperTak 55/2 a useful 110/4. Given a high quality TC and a fast host lens, good results are possible. However with the high Mp sensors now in common use, a cropped image without the TC may be just as good or even better so what is the point? Only perhaps cropping options of the TC image which starts with full Mp? >> >> Alan C >> -- >> %(real_name)s Pentax-Discuss Mail List >> To unsubscribe send an email to pdml-leave@pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. > > -- > America wasn't founded so that we could all be better. > America was founded so we could all be anything we damn well please. > - P.J. O'Rourke > > > -- > This email has been checked for viruses by AVG. > https://www.avg.com > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.

Yes, Paul, I agree. Your images are excellent. Do you crop the TC images & if you cropped an image without the TC to the same size would it be just as good? Alan C On 16-Jul-21 08:41 PM, Paul Stenquist wrote: > Most of my bird photos are shot with the DA 1.4x. Excellent glass, > > Paul > >> On Jul 16, 2021, at 1:55 PM, P. J. Alling <webstertwentysix@gmail.com> wrote: >> >> The short answer is no they're not a scam. However, most TCs will magnify any shortcomings in the system they are added to. Cheap TCs come with their own sets of optical problems and failings, but a good one, or a matched TC will give good enough results, for a price. The problem is as time goes on you often don't get what you pay for. I played around with a number of TCs inexpensive and in some cases very expensive during and after the film era and the only ones that really were worth while that I used, were the Pentax 1.7 AF adapter, not strictly a TC but it works as one on lenses up to the * 300mm f4.0 twins, with decent results. Though neither of those lenses is the most optically stellar Pentax telephotos. The Vivitar 2x Macro focusing TC worked very well with shorter focal lengths say between 40mm and 100mm, especially on film, on digital it was a little less useful and the images sometimes left a bit to be desired. The Vivitar 70-150mm with it's matched multiplier gave results that were very close to the lens alone, unfortunately that lens was subject to an incredible amount of veiling flair so unless the photo gods were smiling the results were pretty poor most of the time. >> >>> On 7/16/2021 5:00 AM, Alan C wrote: >>> All teleconverters degrade the image to some extent, 2x more than 1.4x. In film & 6Mp days cropping wasn't really an option so they did give more reach without the expense of a longer lens. Long ago I had an M42 Vivitar 2x which made my SuperTak 55/2 a useful 110/4. Given a high quality TC and a fast host lens, good results are possible. However with the high Mp sensors now in common use, a cropped image without the TC may be just as good or even better so what is the point? Only perhaps cropping options of the TC image which starts with full Mp? >>> >>> Alan C >>> -- >>> %(real_name)s Pentax-Discuss Mail List >>> To unsubscribe send an email to pdml-leave@pdml.net >>> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. >> -- >> America wasn't founded so that we could all be better. >> America was founded so we could all be anything we damn well please. >> - P.J. O'Rourke >> >> >> -- >> This email has been checked for viruses by AVG. >> https://www.avg.com >> -- >> %(real_name)s Pentax-Discuss Mail List >> To unsubscribe send an email to pdml-leave@pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.

Not always true. For instance, the Olympus EX-14 is a 1.4x tele converter specifically optically matched with the first series ZD 50-200/2.8-3.5 and ZD 150/2 lenses. While the lenses are super performers all by themselves, they’re actually even better performers when used with the converter. But that’s rare because most tele converters are intended as an inexpensive way to acquire a longer lens rather than as a serious optical complement for high performance. G >>>>> On 7/16/2021 5:00 AM, Alan C wrote: >>>> All teleconverters degrade the image to some extent, 2x more than 1.4x.

Teleconverters are just another tool available to the photographer. I've used teleconverters occasionally for many, many years. I used to have a Tamron 300/f2.8 (and the matched teleconverter). That got replaced by the A* 300/2.8. Although I did (and still do) have the 1.4x and 2x TCs, much of the time I used that lens with the 1.7x AF adapter on a PZ-1p or MZ-S; it's a lot easier to carry (and a lot cheaper) than a lens that can go to 500mm. When we got to the digital era, of course, I was effectively already cropping images - the sensor in the *ist-D was smaller than a frame of 35mm film. I've stuck with that sensor size for now; for what I tend to take photographs of it is a better fit (and easier on the wallet, not to mention making less demands on my computer). But I did pick up the new 1.4x TC that knows how to talk to the SR system. I've even tried using it with the 60-250 zoom. I'm sure there is some loss of image quality from using a TC. But there are a whole lot of other things that can degrade images, too. If you're doing studio shots with an absolutely rigid camera stand, locking the mirror up to avoid vibration, etc. you can get rid of quite a few possible causes. Image processing software gets better every year, too - lens profiles can correct for non-linearities. In fact from what I've seen you can often compensate for a lack of actual pixels - the latest "upscaling" algorithms are astonishing. Looking back on the set of images that rotate through my desktop background, there are far more significant things for me to take care of before I start to worry about using a teleconverter.

I crop the TC images. Heavily cropping an image shot without the TC is usually inferior due to the loss of resolution, Paul > On Jul 17, 2021, at 12:15 AM, Alan C <cole@lantic.net> wrote: > > Yes, Paul, I agree. Your images are excellent. Do you crop the TC images & if you cropped an image without the TC to the same size would it be just as good? > > Alan C > >> On 16-Jul-21 08:41 PM, Paul Stenquist wrote: >> Most of my bird photos are shot with the DA 1.4x. Excellent glass, >> >> Paul >> >>>> On Jul 16, 2021, at 1:55 PM, P. J. Alling <webstertwentysix@gmail.com> wrote: >>> >>> The short answer is no they're not a scam. However, most TCs will magnify any shortcomings in the system they are added to. Cheap TCs come with their own sets of optical problems and failings, but a good one, or a matched TC will give good enough results, for a price. The problem is as time goes on you often don't get what you pay for. I played around with a number of TCs inexpensive and in some cases very expensive during and after the film era and the only ones that really were worth while that I used, were the Pentax 1.7 AF adapter, not strictly a TC but it works as one on lenses up to the * 300mm f4.0 twins, with decent results. Though neither of those lenses is the most optically stellar Pentax telephotos. The Vivitar 2x Macro focusing TC worked very well with shorter focal lengths say between 40mm and 100mm, especially on film, on digital it was a little less useful and the images sometimes left a bit to be desired. The Vivitar 70-150mm with it's matched multiplier gave results that were very close to the lens alone, unfortunately that lens was subject to an incredible amount of veiling flair so unless the photo gods were smiling the results were pretty poor most of the time. >>> >>>> On 7/16/2021 5:00 AM, Alan C wrote: >>>> All teleconverters degrade the image to some extent, 2x more than 1.4x. In film & 6Mp days cropping wasn't really an option so they did give more reach without the expense of a longer lens. Long ago I had an M42 Vivitar 2x which made my SuperTak 55/2 a useful 110/4. Given a high quality TC and a fast host lens, good results are possible. However with the high Mp sensors now in common use, a cropped image without the TC may be just as good or even better so what is the point? Only perhaps cropping options of the TC image which starts with full Mp? >>>> >>>> Alan C >>>> -- >>>> %(real_name)s Pentax-Discuss Mail List >>>> To unsubscribe send an email to pdml-leave@pdml.net >>>> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. >>> -- >>> America wasn't founded so that we could all be better. >>> America was founded so we could all be anything we damn well please. >>> - P.J. O'Rourke >>> >>> >>> -- >>> This email has been checked for viruses by AVG. >>> https://www.avg.com >>> -- >>> %(real_name)s Pentax-Discuss Mail List >>> To unsubscribe send an email to pdml-leave@pdml.net >>> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. >> -- >> %(real_name)s Pentax-Discuss Mail List >> To unsubscribe send an email to pdml-leave@pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. > > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to pdml-leave@pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.