FF TC for the DA* 300mm F4

**Carpon** · 03-09-2017, 02:35 AM

Thank you all for your comments and enlightening information, it made me decide to stick to APS-C. For Macro and wildlife is 90% off what I do. I did however take the DA* 300mm and will pare it with the 1.4 HD TC and now it's practice and more practice. Will post some results soon, wildlife and birds is a totaly difrent ballgame

lot to learn.

normhead · 03-09-2017, 08:21 AM

How do you time this, I was thinking of recording the sound and using the time stamps of the sound file. Is there an easier method?

**Carpon** · 03-09-2017, 12:28 PM

Originally posted by Michaelina2

For what it's worth, a K-3II+DFA 100/2.8 WR+HD 1.4TC is like using the camera paired to a 210mm f/4.0 lens...

The 'snap to focus' time from infinity to the same subject (all other things being equal & both set to f/4.0) at (say) 8 feet takes about half the time for the DFA+HD over the my screw-drive converted DA*200/2.8. So if you are looking for a compact 210/4 kit with excellent IQ, the K-3II paired to a DFA 100/2.8WR+HD 1.4TC should be a no brainer.

Cheers... M

Great tip, I have both so will try this, thanks

zapp · 03-09-2017, 02:02 PM

Originally posted by shardulm

Macro lenses are usually 1:1 magnification and a D-FA 100WR is 1:1 meant for a FF. In theory if you use an APS-C for this lens you are getting increased magnification so it is better or not better depending upon what you want. In general a high megapixel crop sensor with a Macro lens is the best bet for Macro shots. The DOF is also a little more forgiving on an APS-C. So your K-3 is still very useful in that sense IMO.

Not sure what you are smoking in theory, but 1:1 on the sensor means 1:1 on the sensor. Sensor size does not matter at all here. It is 1:1 on FF and 1:1 on APS-C. 1 mm in reality equals 1 mm on your sensor. With a smaller sensor you cover less area. The concept is very simple.
DOF is exactly the same on FF as it is on APS-C then using the same lens, distance setting and aperture, but the area of coverage may change. Pixel size is often different between APS-C and FF cameras and can change per pixel coverage, but pixel size and crop factor are not directly related.

Sandy Hancock · 03-09-2017, 02:11 PM

Here we go again.
I practical terms, using the same lens, a smaller sensor + higher pixel density = more magnification in the resultant image.

**shardulm** · 03-09-2017, 04:02 PM

Originally posted by zapp

Not sure what you are smoking in theory, but 1:1 on the sensor means 1:1 on the sensor. Sensor size does not matter at all here. It is 1:1 on FF and 1:1 on APS-C. 1 mm in reality equals 1 mm on your sensor. With a smaller sensor you cover less area. The concept is very simple.
DOF is exactly the same on FF as it is on APS-C then using the same lens, distance setting and aperture, but the area of coverage may change. Pixel size is often different between APS-C and FF cameras and can change per pixel coverage, but pixel size and crop factor are not directly related.

Thanks for clarifying and good luck with your theory.

normhead · 03-09-2017, 05:23 PM

Originally posted by Sandy Hancock

Here we go again.
I practical terms, using the same lens, a smaller sensor + higher pixel density = more magnification in the resultant image.

The same principal used to apply with Mocrofiche film. It was extremely fine grained. ( size reduction is from 8x11 down to about 1/4 x1/4. ) In a sense fine grain was the same as smaller pixels. And the result was the same. But in this case where the DNG is measured in MP. and output devices are pretty much standard, the tighter pixels spacing provides more magnification and detail, because the output devices are standard across formats and sensors. So unlike microfiche, where you had to have more magnification of your negative in a machine designed for the purpose, in digital, the extra magnification is available to everyone sitting at home in front of their computer.

Some will say that is not really magnification, it's smaller pixels being displayed on the same output devices as bigger pixels. So functionally, it's magnification.

Last edited by normhead; 03-09-2017 at 06:26 PM.

sculptor666 · 03-12-2017, 08:35 AM

the pentax-f 1.7 teleconverter is fine with the da*300mm on full frame. no vignetting.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: DA* 300mm f4 with HD 1.4x TC	Lewser89	Sold Items	3	10-18-2016 06:57 PM
SMC Pentax-DA 55-300mm F4-5.8 ED vs SMC Pentax-DA* 300mm F4 ED [IF] SDM	Budster48	Pentax SLR Lens Discussion	12	06-30-2013 11:00 AM
For Sale - Sold: DFA 50mm F2.8 Macro, DA 300mm F4, DA 17-70mm F4, Sigma 10-20mm F4-5.6 (US/CAN)	Doczi	Sold Items	8	08-16-2010 12:13 PM
For Sale - Sold: Pentax-A 135mm, DA 55-300mm, Tamron MC4 1.4x TC & Tokina 2x TC	Light_Horseman	Sold Items	8	07-08-2009 07:03 PM

03-09-2017, 02:35 AM	#16
Carpon Site Supporter Join Date: Mar 2015 Location: Utrecht, The Netherlands Photos: Albums Posts: 330 Original Poster	Thank you all for your comments and enlightening information, it made me decide to stick to APS-C. For Macro and wildlife is 90% off what I do. I did however take the DA* 300mm and will pare it with the 1.4 HD TC and now it's practice and more practice. Will post some results soon, wildlife and birds is a totaly difrent ballgame lot to learn.

03-09-2017, 08:21 AM	#17
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	How do you time this, I was thinking of recording the sound and using the time stamps of the sound file. Is there an easier method?

03-09-2017, 12:28 PM	#18
Carpon Site Supporter Join Date: Mar 2015 Location: Utrecht, The Netherlands Photos: Albums Posts: 330 Original Poster	Originally posted by Michaelina2 For what it's worth, a K-3II+DFA 100/2.8 WR+HD 1.4TC is like using the camera paired to a 210mm f/4.0 lens... The 'snap to focus' time from infinity to the same subject (all other things being equal & both set to f/4.0) at (say) 8 feet takes about half the time for the DFA+HD over the my screw-drive converted DA*200/2.8. So if you are looking for a compact 210/4 kit with excellent IQ, the K-3II paired to a DFA 100/2.8WR+HD 1.4TC should be a no brainer. Cheers... M Great tip, I have both so will try this, thanks

03-09-2017, 02:02 PM	#19
zapp Pentaxian Join Date: Jul 2011 Posts: 2,388	Originally posted by shardulm Macro lenses are usually 1:1 magnification and a D-FA 100WR is 1:1 meant for a FF. In theory if you use an APS-C for this lens you are getting increased magnification so it is better or not better depending upon what you want. In general a high megapixel crop sensor with a Macro lens is the best bet for Macro shots. The DOF is also a little more forgiving on an APS-C. So your K-3 is still very useful in that sense IMO. Not sure what you are smoking in theory, but 1:1 on the sensor means 1:1 on the sensor. Sensor size does not matter at all here. It is 1:1 on FF and 1:1 on APS-C. 1 mm in reality equals 1 mm on your sensor. With a smaller sensor you cover less area. The concept is very simple. DOF is exactly the same on FF as it is on APS-C then using the same lens, distance setting and aperture, but the area of coverage may change. Pixel size is often different between APS-C and FF cameras and can change per pixel coverage, but pixel size and crop factor are not directly related.

03-09-2017, 02:11 PM	#20
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275	Here we go again. I practical terms, using the same lens, a smaller sensor + higher pixel density = more magnification in the resultant image.

03-09-2017, 04:02 PM	#21
shardulm Loyal Site Supporter Join Date: Jul 2013 Location: Cumming, GA Posts: 793	Originally posted by zapp Not sure what you are smoking in theory, but 1:1 on the sensor means 1:1 on the sensor. Sensor size does not matter at all here. It is 1:1 on FF and 1:1 on APS-C. 1 mm in reality equals 1 mm on your sensor. With a smaller sensor you cover less area. The concept is very simple. DOF is exactly the same on FF as it is on APS-C then using the same lens, distance setting and aperture, but the area of coverage may change. Pixel size is often different between APS-C and FF cameras and can change per pixel coverage, but pixel size and crop factor are not directly related. Thanks for clarifying and good luck with your theory.

03-09-2017, 05:23 PM	#22
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by Sandy Hancock Here we go again. I practical terms, using the same lens, a smaller sensor + higher pixel density = more magnification in the resultant image. The same principal used to apply with Mocrofiche film. It was extremely fine grained. ( size reduction is from 8x11 down to about 1/4 x1/4. ) In a sense fine grain was the same as smaller pixels. And the result was the same. But in this case where the DNG is measured in MP. and output devices are pretty much standard, the tighter pixels spacing provides more magnification and detail, because the output devices are standard across formats and sensors. So unlike microfiche, where you had to have more magnification of your negative in a machine designed for the purpose, in digital, the extra magnification is available to everyone sitting at home in front of their computer. Some will say that is not really magnification, it's smaller pixels being displayed on the same output devices as bigger pixels. So functionally, it's magnification. Last edited by normhead; 03-09-2017 at 06:26 PM.

03-12-2017, 08:35 AM	#23
sculptor666 Pentaxian Join Date: Dec 2013 Location: PA Photos: Gallery Posts: 675	the pentax-f 1.7 teleconverter is fine with the da*300mm on full frame. no vignetting.