With film, especially slides and color prints where a color darkroom was not always practical or when battling grain, teleconverters could very useful in some cases. With today's newer sensors and the fact that nearly everyone has a computer between the camera and the print, it seems that a teleconverter's degradation of the lens system would have a larger adverse impact when compared to cropping, espeically with 16+ MP cameras. I can see it as a composition or focusing aid (with a larger subject image in the viewfinder), and certainly it can be satisfying looking through an instant 1.4x or 1.5x extra focal length with little added weight and cost. Granted, it's a different approach. I can see where some find it preferable to finish a print with all 24 million pixels present even with a slightly softer image than to steal pixels and make the best use of the lens. My question is addressed mainly to folks who used teleconverters with film. Have you found that cropping with digital has largely replaced their use?

Not at all.

In fact, teleconverters from the film era were mostly much lower quality than TCs today. Over the years I tried a bunch of different ones back in the good/bad old days, but ended up only satisfied with and using one particular 1.5X with one or two specific prime lenses. Most other TC and lens combos were pretty disappointing.

Today I use TCs a lot more often. High quality 1.4X and 2X, mostly with 300mm and 500mm prime lenses. But also sometimes with 135mm and 70-200mm. Recently I got a 100-400mm zoom, too, but I haven't had a chance to try it with 1.4X yet, even though it's said to work pretty well and my current cameras are capable of auto focusing the combo.

Cropping is no substitute for teleconverters (BTW, it was nearly as easy to crop film during the enlarging process, as it is to crop digital images in post-processing). There's much more loss of image quality due to cropping.

Better solutions than cropping are to get closer, or use a teleconverter, or if using a full frame camera you might switch to a "crop sensor" camera, which has some "free teleconverter" effect. By that I mean that when used on a crop camera the lens "acts" longer, but there's no penalty of lost light and/or reduced resolution, the way there is with an actual teleconverter.

Let me give you an example. We did a careful comparison a while back, with a Canon full frame camera (22MP 5D Mark II) and a Canon 1.6X APS-C model (18MP 7D). We took the same shot from the same place with the same lens... then cropped the full frame image down to match the APS-C image. Essentially, that's the same thing as cropping an image to emulate a 1.6X teleconverter, right?

By the time that's done, only about 8MP remained of the the 22MP FF image... while the 7D's 18MP image was still 18MP. The uncropped image from the APS-C camera was clearly superior to the cropped image from the FF camera.

What's happening in this example is that the difference in sensor area is more greatly reduced than you might initially expect. Same thing will happen if you crop to emulate a teleconverter's effect.

A full frame sensor is 24x36mm or 864 square mm... while a Canon APS-C sensor is about 22x15mm or 330 square mm. So only about 38% of that original FF image remains after cropping to match the smaller format. 38% of 22MP is 8.36MP. Personally, I'd rather have an 18MP image!

Similar would be true cropping any image to emulate the effects of a teleconverter. It would mean a little less loss with a 1.4X TC, slightly more for a 1.7X TC or a lot more cropping to emulate a 2X TC. In fact, cropping to the same image rendered with a 2X would leave little more than 25% of the original image data! Rather than a 22MP image made with that 5D Mark II camera and lens fitted with a 2X TC, cropping the image to the same angle of view you'd end up with an image of less than 6MP! Image quality would be greatly reduced, as a result.

So, in other words, your digital images will probably be a lot better using a teleconverter instead of cropping images

Yes, there's some loss if image quality whenever a TC is used, too. That's just the nature of optics... when you add a bunch of elements, there's going to be something lost from the light that has to pass through them. However, exactly how is lost much varies greatly depending upon the quality of the lens, as well as the strength and quality of the TC, plus how well the two complement each other. There are lots of variables. But in general 1.4X "cost" less image quality than 1.7X or 2X and teleconverters work best on prime lenses, as opposed to zooms. And, almost always, teleconverters work best on telephoto lenses.

It also greatly depends to upon the size of print being planned...

Yes, if you are using a $3500 50MP camera (such Canon 5DS-R) with a $10,000 400mm f2.8 lens.... cropping to a roughly 13MP image (equivalent to using a 2X teleconverter) would leave you with an image that could make a pretty nice 8x10 or 11x14 print. But perhaps not if yours is a $1500 20MP camera (such as a Canon 6D) and a $1500 400mm f5.6 lens.... which would end up cropped down to about 5MP, nowhere near as "enlargeable" for printing. OTOH, if you were using a cheaper 1.4X teleconverter and a consumer-grade $1500 150-600mm zoom, you might be better off just using a mild crop instead of the TC + 600mm combo.

Even with the high-end setup, if you wanted to print any larger you'd probably be better not cropping and instead putting a high quality 2X between that 400mm and camera, giving you a full 50MP image to work with. Of course, even better still would be to use an 800mm lens directly on the camera without any TC or any cropping at all.

There are just a lot of variables. I can only say from my own experiences that I use teleconverters a lot more frequently and freely today shooting digital, than I ever did back in the days of film. Partly that's because the lenses and TCs are better than they were back then. But also because I always try to minimize cropping, since it generally has a lot more effect than people realize. OTOH, the 20MP and larger cameras I use today allow for a bit more cropping than the 6 and 8MP DSLRs that I used ten or twelve years ago. And, it also depends upon the final use... such as print size (BTW, film was more tolerant of enlargement, than digital is).

Not at all.

In fact, teleconverters from the film era were mostly much lower quality than TCs today. Over the years I tried a bunch of different ones back in the good/bad old days, but ended up only satisfied with and using one particular 1.5X with one or two specific prime lenses. Most other TC and lens combos were pretty disappointing.

Today I use TCs a lot more often. High quality 1.4X and 2X, mostly with 300mm and 500mm prime lenses. But also sometimes with 135mm and 70-200mm. Recently I got a 100-400mm zoom, too, but I haven't had a chance to try it with 1.4X yet, even though it's said to work pretty well and my current cameras are capable of auto focusing the combo.

Cropping is no substitute for teleconverters (BTW, it was nearly as easy to crop film during the enlarging process, as it is to crop digital images in post-processing). There's much more loss of image quality due to cropping.


Better solutions than cropping are to get closer, or use a teleconverter, or if using a full frame camera you might switch to a "crop sensor" camera, which has some "free teleconverter" effect. By that I mean that when used on a crop camera the lens "acts" longer, but there's no penalty of lost light and/or reduced resolution, the way there is with an actual teleconverter.

Let me give you an example. We did a careful comparison a while back, with a Canon full frame camera (22MP 5D Mark II) and a Canon 1.6X APS-C model (18MP 7D). We took the same shot from the same place with the same lens... then cropped the full frame image down to match the APS-C image. Essentially, that's the same thing as cropping an image to emulate a 1.6X teleconverter, right?

By the time that's done, only about 8MP remained of the the 22MP FF image... while the 7D's 18MP image was still 18MP. The uncropped image from the APS-C camera was clearly superior to the cropped image from the FF camera.

What's happening in this example is that the difference in sensor area is more greatly reduced than you might initially expect. Same thing will happen if you crop to emulate a teleconverter's effect.

A full frame sensor is 24x36mm or 864 square mm... while a Canon APS-C sensor is about 22x15mm or 330 square mm. So only about 38% of that original FF image remains after cropping to match the smaller format. 38% of 22MP is 8.36MP. Personally, I'd rather have an 18MP image!

Similar would be true cropping any image to emulate the effects of a teleconverter. It would mean a little less loss with a 1.4X TC, slightly more for a 1.7X TC or a lot more cropping to emulate a 2X TC. In fact, cropping to the same image rendered with a 2X would leave little more than 25% of the original image data! Rather than a 22MP image made with that 5D Mark II camera and lens fitted with a 2X TC, cropping the image to the same angle of view you'd end up with an image of less than 6MP! Image quality would be greatly reduced, as a result.

So, in other words, your digital images will probably be a lot better using a teleconverter instead of cropping images

Yes, there's some loss if image quality whenever a TC is used, too. That's just the nature of optics... when you add a bunch of elements, there's going to be something lost from the light that has to pass through them. However, exactly how is lost much varies greatly depending upon the quality of the lens, as well as the strength and quality of the TC, plus how well the two complement each other. There are lots of variables. But in general 1.4X "cost" less image quality than 1.7X or 2X and teleconverters work best on prime lenses, as opposed to zooms. And, almost always, teleconverters work best on telephoto lenses.

You are living in the PAST-

I am here to say that I do not believe ANYONE here has EVER actually tried cropping with pixel enlargement and made good sized prints. 20+ mp on a crop frame works very well with Sony's CIZ - yes I know JPEG - and that is for another argument ....but you could do the same thing with raw - just takes longer. The better sensors (higher pixel density) , lenses, and software today are what allow very good cropping - with - pixel enlargement for larger prints. Many here, would view this as "CHEATING" - but I will take it - cause it WORKS.

IMO, Teleconverters/extenders are a thing of the past .......and I have shot both ways - with GOOD lenses and extenders ( Canon 300 2.8 and 2XII). The loss of 2-stops ISO, shallow DOF, and the size/ weight and AF deterioration were always a burden.

Does a 600mm f4 lens show better IQ than a 300mm f4 with 2X CIZ - in most cases YES. But if you do not have the money OR the inclination to carry/manage the 600 f4, I say the 300 with 2X Sony CIZ (or equivalent) on a crop sensor is the best substitute ! ( and NOT with extenders). There are NO cost, weight or compatibility issues with cropping. And, when you use a M4/3 or a 1 inch sensor - again, you are basically CROPPING. This my experience......

With film, especially slides and color prints where a color darkroom was not always practical or when battling grain, teleconverters could very useful in some cases. With today's newer sensors and the fact that nearly everyone has a computer between the camera and the print, it seems that a teleconverter's degradation of the lens system would have a larger adverse impact when compared to cropping, espeically with 16+ MP cameras. I can see it as a composition or focusing aid (with a larger subject image in the viewfinder), and certainly it can be satisfying looking through an instant 1.4x or 1.5x extra focal length with little added weight and cost. Granted, it's a different approach. I can see where some find it preferable to finish a print with all 24 million pixels present even with a slightly softer image than to steal pixels and make the best use of the lens. My question is addressed mainly to folks who used teleconverters with film. Have you found that cropping with digital has largely replaced their use?

Sony's CIZ is an algorithm that makes assumptions, very logical assumptions, but still assumptions. The pixels generated by the software emulates as if the pixel was really there. But does it actually create the exact pixel value if there had been an actual pixel there to produce a value? I have no doubt that the algorithm produces a value close to it, but it is not quite the same. For maybe most people like you and others this is acceptable. But for my taste, if I paid for a camera with 20 mp, then I want to produce an image as close to that 20 mp as possible without any type of cropping. Will there be a noticeable difference between the CIZ picture and a full pixel picture? As the size of the file gets smaller such that the CIZ program has to generate more and more pixels for the image, the answer will eventually be yes. There is a limit to the generation of false data.

For you and others that may be acceptable. But for amfoto1, myself, and others, we actually want the pixels.

I will still assert you have not actually seen the differences .......

Re:pure optical IQ - using CIZ vs an extender you will see a slight difference - in my eyes, the "differences" are neither good nor bad , just different. But, there are other IQ contributors where CIZ ( and other pixel enlargement schemes) clearly beats extenders such as maintaining ISO, AF and DOF performance as well as cost and compatibility issues.

Those of us who can afford big long lenses and can carry/manage them, will prefer the native lens - and rightfully so ! Most of us who can't, should forget about extenders and crop with pixel enlargement - that is my assertion.

When you consider that at 2X the CIZ is making 4 pixels from 1 it is truly amazing - but very counter intuitive I know! Rather than sticking our nose up at this, maybe we ( most of us) should be embracing it ?

Why should we embrace it just because you do?? I won't stick my nose up at it either, it's just an option. "At 2X the CIZ is making 4 pixels from 1" almost sounds like virtual sex, something that's not real. I'm glad you enjoy it and that it is working for you but as to "most of us" how about some of us. We all know that your in the business of selling and that's great, we need you but I'm on the other side and I buy and I hope people will learn how to use the things that they have already before spending so much more on a new system. Buying a 1.4, 1.7 or a 2X TC and learning how to use it is a lot cheaper then having to change everything. I'm from the old school and much prefer optical zoom to digital. Just my thoughts because I remember how much $$ it cost me to go from film , Hasselblads' to digital.

Because it works ! ......and is amazing.

- and, you do not HAVE to buy a new ( Sony) system - use what you have. You do need a good lens and sensor though - and good technique to extract the most from what you have - Now, was'nt that CHEAP enough for you ?? You can use the default Adobe "Bicubic smoother " pixel enlargement in their programs - at 10% or less per each enlargement step - just to be safe -and use raw if you MUST.

I just get tired of people whining they need more "reach" ! .........and complaining about extenders !

Pony up for the 600 f4 or CROP what you have and do not be afraid to pixel enlarge !

Because it works ! ......and is amazing.

- and, you do not HAVE to buy a new ( Sony) system - use what you have. You do need a good lens and sensor though - and good technique to extract the most from what you have - Now, was'nt that CHEAP enough for you ?? You can use the default Adobe "Bicubic smoother " pixel enlargement in their programs - at 10% or less per each enlargement step - just to be safe -and use raw if you MUST.

I just get tired of people whining they need more "reach" ! .........and complaining about extenders !

Pony up for the 600 f4 or CROP what you have and do not be afraid to pixel enlarge !

I don't see the point of bringing film into the question. You are asking about TC versus crop on digital cameras. But, the answer is essentially the same for film or digital. If you have sufficient resolution without TC, then don't use a TC. If your lens has better resolution than the sensor, then you will most likely see improvement in using a TC versus crop. If not, then you will most likely see degradation in using a TC versus crop.

So don't put a TC on a crappy zoom lens. And don't overdo the TC on a quality zoom lens. I'll use a 1.4 on a good zoom, but I'll go as high as 2.0 on a good prime lens. My 300 f/2.8 is great with 2x on my D750. Not so good on my D7100; I only use a 1.7 on it. And I only us a TC because I can't get closer to my subject.