Kenko Teleplus HD 1.4x

Kenko Teleplus HD 1.4X works well with EOS M5.

With Kenko the aperture goes down by 1 stop automatically. For example, F/4 lenses become F/5.6 lenses. But interestingly, my 28/1.8 and 50/1.4 maintain their own apertures. Does it happen because they are primes or because they are so old lenses? Is the converter doing something with electronic ICs other than electrical wired between the front and back pins?

Now my 55-250/4-5.6 IS STM can become 77-350/5.6-8 with the teleconverter. If the cropped factor is considered, it is 123-560. Wow!

Enjoy!

I was just looking at getting this teleconverter yesterday and would be very interested to know how it performs with the 55-250 STM lens you have. I've been seriously impressed by that lens but it's not quite long enough for capturing small wildlife - birds, otters, mountain hares etc. Anything that can give a bit more reach without having to buy a much more expensive lens would be great. Do you have any example shots you could post, please?

I posted few shots somewhere on the DPR forum, but I don´t really remember what and where. I had very busy summer, so I didn´t get out to stretch this particular combo.

Well, I found my last one on the PC desktop:



Too bad it seems I won´t continue for long time, as I´m most probably leaving Canon brand. This combo is quite magic for its price, and I will always recommend it to Canon users with crop sensors...

That's very impressive! Thanks for posting, crashpc. I'll have to put one of these teleconverters on my wanted list. Also on this list is a speedbooster that will allow EF lenses to be fitted to EF-M mount cameras that will divide the focal length by 1.6 and make the lens over a stop brighter! I was wondering if one could also be made for the new 'R' mount lenses to achieve this, too? Wouldn't that be something? But who will make these for us?

t0adst00l said:

I was just looking at getting this teleconverter yesterday and would be very interested to know how it performs with the 55-250 STM lens you have. I've been seriously impressed by that lens but it's not quite long enough for capturing small wildlife - birds, otters, mountain hares etc. Anything that can give a bit more reach without having to buy a much more expensive lens would be great. Do you have any example shots you could post, please?

Click to expand...

I got these for you just a few minutes ago. All are SOOC. Hope they will be helpful.

1. Near (about 2-3m away)


55-250@250mm with TC 1.4X


55-250@250mm without TC, F/5.6



2. Far (100m?)


55-250@250mm with TC 1.4X


55-250@250mm without TC, F/5.6

Keep in mind that SOOC, images with teleconverter and without might not be fully comparable, as you will see more atmospheric distortions, and the camera will see different situation, thus giving different exposure settings and such.

Of course, contrast takes little hit, but that one can be repaired in PP. The sharpness is still there and it is plenty for 4K Viewing I would say.

Hope you like it!

t0adst00l said:

That's very impressive! Thanks for posting, crashpc. I'll have to put one of these teleconverters on my wanted list. Also on this list is a speedbooster that will allow EF lenses to be fitted to EF-M mount cameras that will divide the focal length by 1.6 and make the lens over a stop brighter! I was wondering if one could also be made for the new 'R' mount lenses to achieve this, too? Wouldn't that be something? But who will make these for us?

Click to expand...

I was interested in focal reducer seriously. But now my interest was gone. First of all, the newly coming 32mm looks awesome. EF 50mm adapted is useful. EFM 22 and 11-22 are wonderful. I want to have a good standard zoom, but such EF and EFS are big and heavy. For what focal ranges or lenses do you need it? I am satisfied just with enjoying the multiplied forcal length by a simple adapter. My heart wants a focal reducer, but my reason does not allow me to have it.

Many thanks for doing these shots, lumenite. I can see there's a little loss of contrast and the red of the sign looks less vibrant but, as you say, the detail is there so those can be boosted in post processing. The converter is around £130 here in the UK so it will be a cheap way to get more reach. I'll have to do some hunting around to find the best price now!

Thanks again! Mark

Less than optimal teleconverters are no better than just cropping the original image. Often, it is actually worse.

Here is your original image with the teleconverter


55-250mm STM plus Kenko 1.4X TC



Here is your 2nd image without the TC, but cropped to 12.2mp and then upscaled back to 24MP


55-250mm STM cropped to match above image and then upscaled back to 24mp



Detail is nearly identical between the two images, but the cropped and upscaled version shows noticeably better contrast. This was just a very quick example in photoshop. The 2nd image could be even better by using more sophisticated scaling algorithms.

Well, I did my comparison on charts where resolution can be seen. Both 1.4x, 2x and even 1.4x + 2x gave more real resolution than lens without TC.

Resolution and contrast are two differen parameters. Also what I see is that the teleconverted lens gets more exposure, making the image effectively brighter.

So I canno agree on that conclusion.

nnowak said:

Less than optimal teleconverters are no better than just cropping the original image. Often, it is actually worse.

Click to expand...

...

nnowak said:

Detail is nearly identical between the two images, but the cropped and upscaled version shows noticeably better contrast. This was just a very quick example in photoshop. The 2nd image could be even better by using more sophisticated scaling algorithms.

Click to expand...

I agree with you in many ways. But two Fs remain in my mind.

1. Framing. I would like to see what I will get through viewfinder while taking the shot. It is impossible with OVF, if the image is cropped or upscaled after taken. Although some OVFs of the rangefinder cameras have the frame lines for several focal lengths, it is not convenient. However, the age of EVF and digital can give this function easily with some loss of image quality.

2. Focusing. If the image is cropped, its focus point gets large and the accuracy will lose its precision. Here Canon may show its strength. Every pixel consists of dual phases, which means every pixel can be AF point virtually. So EOS R can be said to have 5655 AF points. IMHO, if Canon wants to operate the cropping option with DPAF, they can adjust and remap the focus points relatively.

So, as the one who does not use full resolution by and large, I wish Canon would give digital zoom or crop mode just as Sony does or other compact cameras provide.

If camera does not give digital zoom option, those who want these two might need a teleconverter.

Okay guys, here is another comparison:

Bare lens 55-250mm IS STM, random shot at home:



55-250mm IS STM with 1,4x Kenko TC:



For real viewing sizes and distances, I would still consider this flawless.

55-250mm IS STM with Kenko 2x TC:



Okay, the image quality took a hit here. BUT, the resolution is there, and it is perfectly usable for 4k Viewing. I would not hesitate to shoot with this combo if reach really was primary goal. The reach is there.

55-250mm IS STM with both 1,4x and 2x teleconverters on:



The image is significantly degraded here, but still OKAY for 4K usage and expected viewing distance. It gets quite good for 2560p viewing and very good for FullHD after some more processing. Still usable for need of absolute resolution.

All images are processed in LR to taste, but I didn´t lose much time with these.

Here is original of bare lens shot:

http://leteckaposta.cz/514506521

Feel free to do whatever magic is available, to upscale it to the 2x+1,4x resolution of the image with the same amount of detail. Please, take it as friendly challenge. I will take both better and worse result. As I´m a rookie in upscaling tech, I might be pleasantly surprised...

I would also like to do direct comparison with some superzooms, but that would need cooperation with someone else. This is effectively 1120mm combo. BUT, AF is rather not usable with this setup.