1.4 or 1.7 teleconverter ?

dewolf · 12-21-2016, 08:32 AM

I have the K5iis, and the DA* 300 F4. I am looking to extend that reach on occasion for smaller birds. I would like to see an actual visual comparison between a 300mm without a TC and then an example of the same image with the 1.4 and 1.7x. I couldn't find a forum specific to my request, and I don't even know if someone has already posted such a series . If they have could you direct me to the link ?

Many thanks.

DeWolf

**marcusBMG** · 12-21-2016, 08:42 AM

normhead has posted a number of comparative results with TC's in the 300mm lens club (albeit mainly with the DA 200*mm). Use advanced search...

**Scorpio71GR** · 12-21-2016, 10:32 AM

One thing with the 1.7 adapter to remember is that is not true autofocus. You have to manually focus the lens first to get it close and then finish with autofocus. Also the adapter focuses not the lens and it is screwdrive.

dewolf · 12-21-2016, 11:51 AM

Originally posted by marcusBMG

normhead has posted a number of comparative results with TC's in the 300mm lens club (albeit mainly with the DA 200*mm). Use advanced search...

tried advanced search, no results. apparently My brain and the advance search do not agree lol. I will just go through the listings, im sure I will find it eventually

**marcusBMG** · 12-21-2016, 12:08 PM

Originally posted by dewolf

tried advanced search, no results. apparently My brain and the advance search do not agree lol. I will just go through the listings, im sure I will find it eventually

Search Results - PentaxForums.com

dewolf · 12-21-2016, 12:46 PM

Originally posted by marcusBMG

Search Results - PentaxForums.com

Thank you Very much. I tried his name, TC, Teleconverter, 1.4 and 1.7 and just got 0 results. I must not understand whats wanted in that form.
I just need to visualize what 1.4 and 1.7 looks like as apposed to no TC. I guess I could take a fixed image of something at 175mm and again at 245 mm to get a comparison of a 1.4 and at 297mm for a 1.7 or thereabouts. looking into the Pentax HD 1.4 and Kenco 1.7. I almost always have to pre-focus on small subjects anyway so AF isn't so much an issue. I was not aware however that the screw drive was used. Interesting.

**onlineflyer** · 12-21-2016, 01:50 PM

I also have the K-5iis and the DA 300mm lens, along with a 1.7x AF adapter. Why the 1.7x? Becuase I also have the A*300mm and K 200mm F2.5 that are manual focus lenses. I can use the 1.7x on all three lenses,although I never use it on the DA 300mm. If I only had the DA 300, I would have purchased the 1.4x since they are all (Kenko, Sigma, Tamron, Pentax) true teleconverters that allow the lens to focus, rather than the adapter..

narual · 12-21-2016, 01:54 PM

You could use the Focal length comparison tool, Tamron USA, it doesn't have birds, but it should give you an idea.

It's not a very large difference between 1.4 and 1.7 on the 300mm though. You're going from a 5.2 degree angle at 300 to a 3.7 degree with the 1.4, and the 1.7 gets you to 3.1 -- and given teh comparitive quality between the 1.4 HD and the kenko 1.7, you're probably better off with the 1.4 and doing a little cropping. (the Kenko 1.5 gets good reviews though, and gets you to 3.4 degrees, while being considerably cheaper than the 1.4 HD)

**Scorpio71GR** · 12-21-2016, 02:19 PM

I use the 1.7 on the DA*60-250 which islso f4 nd it works well if you have enough light. I really do jot notice any difference with or without the converter.

**onlineflyer** · 12-21-2016, 02:31 PM

Another thing to remember is the 300mm on a APS-C sensor has a field-of-view of approximately 450mm. Add a 1.4x teleconverter and it becomes 630mm. Add a 1.7x and it's 765mm. Sometime is begins to be too close.

---------- Post added 12-21-16 at 04:36 PM ----------

Originally posted by Scorpio71GR

I use the 1.7 on the DA*60-250 which is f4 and it works well if you have enough light. I really do not notice any difference with or without the converter.

That's one of the reason the 1.7x mates so well with the 200mm f2.8 and 200mm f2.5. Both fast lenses.

**Scorpio71GR** · 12-21-2016, 03:58 PM

Originally posted by onlineflyer

That's one of the reason the 1.7x mates so well with the 200mm f2.8 and 200mm f2.5. Both fast lenses.

Very true, it get much better success with my Tamron 70-200 2.8. I also use it on my Rokinon 85 1.4.

dewolf · 12-21-2016, 06:50 PM

Originally posted by onlineflyer

I also have the K-5iis and the DA 300mm lens, along with a 1.7x AF adapter. Why the 1.7x? Becuase I also have the A*300mm and K 200mm F2.5 that are manual focus lenses. I can use the 1.7x on all three lenses,although I never use it on the DA 300mm. If I only had the DA 300, I would have purchased the 1.4x since they are all (Kenko, Sigma, Tamron, Pentax) true teleconverters that allow the lens to focus, rather than the adapter..

so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. amd I getting that right ?

---------- Post added 12-21-16 at 08:52 PM ----------

Originally posted by narual

You could use the Focal length comparison tool, Tamron USA, it doesn't have birds, but it should give you an idea.

It's not a very large difference between 1.4 and 1.7 on the 300mm though. You're going from a 5.2 degree angle at 300 to a 3.7 degree with the 1.4, and the 1.7 gets you to 3.1 -- and given teh comparitive quality between the 1.4 HD and the kenko 1.7, you're probably better off with the 1.4 and doing a little cropping. (the Kenko 1.5 gets good reviews though, and gets you to 3.4 degrees, while being considerably cheaper than the 1.4 HD)

that'svery good information. I can see where the 1.4 would likely do the job for me then. I don't need a lot of extra reach, just a little. and I would hate to degrade the sharpness of this 300F4 by over doing it. I can get within 60 ft of most the small birds during the season, and crop up. I would likel to reach in a little more for detail, and the the extra bokeh, sometimes the bokeh on the 300 is a little grainy

**onlineflyer** · 12-21-2016, 07:00 PM

Originally posted by dewolf

so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. and I getting that right ?

Yes, that is correct.

**Scorpio71GR** · 12-22-2016, 03:24 PM - **1 Like**

Originally posted by dewolf

so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. amd I getting that right ?[COLOR=Silver]

Yes the 1.7 adapter was designed to allow autofocus with manual focus lenses. The 1.7 adapter has a screwdrive connection to the camera body only and does the focusing. You have to prefocus the lens first so the adapter can finish. The adapter does not have much of a focus throw. The 1.4 teleconverter has focus connectionsthat go straight from the camera to the lens. Focusing will be done either by the screwdrive or the in lens motor.

I do not own the DA*300 but I have the DA*60-250 and I do use that with the 1.7. This at 250mm with the 1.7 for 425mm at f7.1.

dewolf · 12-22-2016, 05:10 PM

Originally posted by Scorpio71GR

Yes the 1.7 adapter was designed to allow autofocus with manual focus lenses. The 1.7 adapter has a screwdrive connection to the camera body only and does the focusing. You have to prefocus the lens first so the adapter can finish. The adapter does not have much of a focus throw. The 1.4 teleconverter has focus connectionsthat go straight from the camera to the lens. Focusing will be done either by the screwdrive or the in lens motor.

I do not own the DA*300 but I have the DA*60-250 and I do use that with the 1.7. This at 250mm with the 1.7 for 425mm at f7.1.

I have heard great things about the 60-250. That was on my short list when choosing the 300. I realize now a 450mm might have been a better choice lol. But I am happy with the sharpness of the 300. Your image with the 1.7 is beautifully sharp, more so than I would have imagined for having a TC on it.

12-21-2016, 08:32 AM	#1
dewolf Guest	1.4 or 1.7 teleconverter ? I have the K5iis, and the DA* 300 F4. I am looking to extend that reach on occasion for smaller birds. I would like to see an actual visual comparison between a 300mm without a TC and then an example of the same image with the 1.4 and 1.7x. I couldn't find a forum specific to my request, and I don't even know if someone has already posted such a series . If they have could you direct me to the link ? Many thanks. DeWolf

12-21-2016, 06:50 PM	#12
dewolf Guest	Originally posted by onlineflyer I also have the K-5iis and the DA 300mm lens, along with a 1.7x AF adapter. Why the 1.7x? Becuase I also have the A300mm and K 200mm F2.5 that are manual focus lenses. I can use the 1.7x on all three lenses,although I never use it on the DA 300mm. If I only had the DA 300, I would have purchased the 1.4x since they are all (Kenko, Sigma, Tamron, Pentax) true teleconverters that allow the lens to focus, rather than the adapter.. so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. amd I getting that right ? ---------- Post added 12-21-16 at 08:52 PM ---------- Originally posted by narual You could use the Focal length comparison tool, Tamron USA, it doesn't have birds, but it should give you an idea. It's not a very large difference between 1.4 and 1.7 on the 300mm though. You're going from a 5.2 degree angle at 300 to a 3.7 degree with the 1.4, and the 1.7 gets you to 3.1 -- and given teh comparitive quality between the 1.4 HD and the kenko 1.7, you're probably better off with the 1.4 and doing a little cropping. (the Kenko 1.5 gets good reviews though, and gets you to 3.4 degrees, while being considerably cheaper than the 1.4 HD) that'svery good information. I can see where the 1.4 would likely do the job for me then. I don't need a lot of extra reach, just a little. and I would hate to degrade the sharpness of this 300F4 by over doing it. I can get within 60 ft of most the small birds during the season, and crop up. I would likel to reach in a little more for detail, and the the extra bokeh, sometimes the bokeh on the 300 is a little grainy Last edited by dewolf; 12-21-2016 at 06:58 PM.*

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12-21-2016, 08:42 AM	#2
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,870	normhead has posted a number of comparative results with TC's in the 300mm lens club (albeit mainly with the DA 200*mm). Use advanced search...

12-21-2016, 10:32 AM	#3
Scorpio71GR Loyal Site Supporter Join Date: Nov 2014 Location: Michigan Photos: Gallery \| Albums Posts: 6,036	One thing with the 1.7 adapter to remember is that is not true autofocus. You have to manually focus the lens first to get it close and then finish with autofocus. Also the adapter focuses not the lens and it is screwdrive.

12-21-2016, 11:51 AM	#4
dewolf Guest	Originally posted by marcusBMG normhead has posted a number of comparative results with TC's in the 300mm lens club (albeit mainly with the DA 200*mm). Use advanced search... tried advanced search, no results. apparently My brain and the advance search do not agree lol. I will just go through the listings, im sure I will find it eventually

12-21-2016, 12:08 PM	#5
marcusBMG Site Supporter Join Date: Nov 2012 Location: North Wales Photos: Gallery \| Albums Posts: 2,870	Originally posted by dewolf tried advanced search, no results. apparently My brain and the advance search do not agree lol. I will just go through the listings, im sure I will find it eventually Search Results - PentaxForums.com

12-21-2016, 12:46 PM	#6
dewolf Guest	Originally posted by marcusBMG Search Results - PentaxForums.com Thank you Very much. I tried his name, TC, Teleconverter, 1.4 and 1.7 and just got 0 results. I must not understand whats wanted in that form. I just need to visualize what 1.4 and 1.7 looks like as apposed to no TC. I guess I could take a fixed image of something at 175mm and again at 245 mm to get a comparison of a 1.4 and at 297mm for a 1.7 or thereabouts. looking into the Pentax HD 1.4 and Kenco 1.7. I almost always have to pre-focus on small subjects anyway so AF isn't so much an issue. I was not aware however that the screw drive was used. Interesting.

12-21-2016, 01:50 PM	#7
onlineflyer Loyal Site Supporter Join Date: Jul 2010 Location: NW Ohio Photos: Gallery \| Albums Posts: 2,094	I also have the K-5iis and the DA 300mm lens, along with a 1.7x AF adapter. Why the 1.7x? Becuase I also have the A*300mm and K 200mm F2.5 that are manual focus lenses. I can use the 1.7x on all three lenses,although I never use it on the DA 300mm. If I only had the DA 300, I would have purchased the 1.4x since they are all (Kenko, Sigma, Tamron, Pentax) true teleconverters that allow the lens to focus, rather than the adapter..

12-21-2016, 01:54 PM	#8
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	You could use the Focal length comparison tool, Tamron USA, it doesn't have birds, but it should give you an idea. It's not a very large difference between 1.4 and 1.7 on the 300mm though. You're going from a 5.2 degree angle at 300 to a 3.7 degree with the 1.4, and the 1.7 gets you to 3.1 -- and given teh comparitive quality between the 1.4 HD and the kenko 1.7, you're probably better off with the 1.4 and doing a little cropping. (the Kenko 1.5 gets good reviews though, and gets you to 3.4 degrees, while being considerably cheaper than the 1.4 HD)

12-21-2016, 02:19 PM	#9
Scorpio71GR Loyal Site Supporter Join Date: Nov 2014 Location: Michigan Photos: Gallery \| Albums Posts: 6,036	I use the 1.7 on the DA*60-250 which islso f4 nd it works well if you have enough light. I really do jot notice any difference with or without the converter.

12-21-2016, 02:31 PM	#10
onlineflyer Loyal Site Supporter Join Date: Jul 2010 Location: NW Ohio Photos: Gallery \| Albums Posts: 2,094	Another thing to remember is the 300mm on a APS-C sensor has a field-of-view of approximately 450mm. Add a 1.4x teleconverter and it becomes 630mm. Add a 1.7x and it's 765mm. Sometime is begins to be too close. ---------- Post added 12-21-16 at 04:36 PM ---------- Originally posted by Scorpio71GR I use the 1.7 on the DA60-250 which is f4 and it works well if you have enough light*. I really do not notice any difference with or without the converter. That's one of the reason the 1.7x mates so well with the 200mm f2.8 and 200mm f2.5. Both fast lenses.

12-21-2016, 03:58 PM	#11
Scorpio71GR Loyal Site Supporter Join Date: Nov 2014 Location: Michigan Photos: Gallery \| Albums Posts: 6,036	Originally posted by onlineflyer That's one of the reason the 1.7x mates so well with the 200mm f2.8 and 200mm f2.5. Both fast lenses. Very true, it get much better success with my Tamron 70-200 2.8. I also use it on my Rokinon 85 1.4.

12-21-2016, 07:00 PM	#13
onlineflyer Loyal Site Supporter Join Date: Jul 2010 Location: NW Ohio Photos: Gallery \| Albums Posts: 2,094	Originally posted by dewolf so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. and I getting that right ? Yes, that is correct.

12-22-2016, 03:24 PM - 1 Like	#14
Scorpio71GR Loyal Site Supporter Join Date: Nov 2014 Location: Michigan Photos: Gallery \| Albums Posts: 6,036	Originally posted by dewolf so the 1.4 allows the lens to focus and the 1.7 focuses for the lens. amd I getting that right ?[COLOR=Silver] Yes the 1.7 adapter was designed to allow autofocus with manual focus lenses. The 1.7 adapter has a screwdrive connection to the camera body only and does the focusing. You have to prefocus the lens first so the adapter can finish. The adapter does not have much of a focus throw. The 1.4 teleconverter has focus connectionsthat go straight from the camera to the lens. Focusing will be done either by the screwdrive or the in lens motor. I do not own the DA300 but I have the DA60-250 and I do use that with the 1.7. This at 250mm with the 1.7 for 425mm at f7.1.

12-22-2016, 05:10 PM	#15
dewolf Guest	Originally posted by Scorpio71GR Yes the 1.7 adapter was designed to allow autofocus with manual focus lenses. The 1.7 adapter has a screwdrive connection to the camera body only and does the focusing. You have to prefocus the lens first so the adapter can finish. The adapter does not have much of a focus throw. The 1.4 teleconverter has focus connectionsthat go straight from the camera to the lens. Focusing will be done either by the screwdrive or the in lens motor. I do not own the DA300 but I have the DA60-250 and I do use that with the 1.7. This at 250mm with the 1.7 for 425mm at f7.1. I have heard great things about the 60-250. That was on my short list when choosing the 300. I realize now a 450mm might have been a better choice lol. But I am happy with the sharpness of the 300. Your image with the 1.7 is beautifully sharp, more so than I would have imagined for having a TC on it.