What is the crop factor?!

jcasey52 · 03-22-2013, 09:38 AM

Funny but I've recently decided to stop using zoom lenses, regardless of how 'good' they are! I've shot primes for years and always had better luck with them. Recently I sold my last zoom and went back to older Super Takumar and Zeiss Flektogon lenses. Amazingly, the saying of "they don't make 'em like they used to" can be true! I've bought some mint condition lenses for a fraction of what you would pay for newer, plastic barrel lenses and the image quality is superb! Two lenses I'm fond of in particular are the Flektogon 20mm F2.8 and the Flek 35mm F2.4. These two lenses have very low distortion, especially the 20mm, they are MC (multi-coated) lenses so they have better light transmission and less flare than earlier models and the picture quality is impressive.

Distortion will ALWAYS be a factor with any lens design but the better the lens maker, typically the less distortion there is. Zeiss for example was originally made in Germany, then they licensed the name and their recipes to manufacturers in other countries. Amazingly, altitude and atmospheric pressure seem to play a big role in lens quality. It's been discovered that lenses made high in the mountains of Germany, where the oxygen was lower, have less distortion and better overall image quality, than Zeiss lenses made in Japan closer to sea level. Go figure!

One benefit I really like with my M42 lenses (older Tak's and Flek's) is that I can use an adapter and mount them both on my Pentax K5IIs AND a Nikon D800E. To me this is huge benefit to be able to work with the same lenses for two different formats and still be able to get incredible image results. In reality, crop sensor or FF doesn't really matter as much, it's the lens that makes the biggest difference IMO.

littledrawe · 03-22-2013, 06:09 PM

How does the apparent increased magnification of the Q fit into all of this then?

vonBaloney · 03-22-2013, 06:44 PM

Originally posted by littledrawe

How does the apparent increased magnification of the Q fit into all of this then?

Q has a 5.5x crop factor, but remember that's compared to full-frame. So compared to Pentax APS-C, which is believe is 1.54, that means a lens on the Q is 3.57x that of (say) a K-5. Now, most people are using adapted lenses on the Q for super-telephoto, but to keep in the realm of focal lengths we are used to seeing we might use a shorter length for example. So for instance, to get the FOV that you'd get from a 100mm on the K-5, you'd use a 28mm on the Q.

Yamanobori · 03-27-2013, 09:22 AM

The 90m is a 1.6X lens. Simply take the format diagonal and use it to divide the focal length. It is much easier to work in the format you are using than one you are not. BTW, that is 48mm in APS or 69mm in 35mm.

jcasey52 · 04-01-2013, 09:59 PM

Throw the Q in the T can and go buy a K-5! ;-)

04-01-2013, 09:59 PM	#20
jcasey52 New Member Join Date: Oct 2012 Posts: 13	Even Better... Throw the Q in the T can and go buy a K-5! ;-)

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03-22-2013, 09:38 AM	#16
jcasey52 New Member Join Date: Oct 2012 Posts: 13	Funny but I've recently decided to stop using zoom lenses, regardless of how 'good' they are! I've shot primes for years and always had better luck with them. Recently I sold my last zoom and went back to older Super Takumar and Zeiss Flektogon lenses. Amazingly, the saying of "they don't make 'em like they used to" can be true! I've bought some mint condition lenses for a fraction of what you would pay for newer, plastic barrel lenses and the image quality is superb! Two lenses I'm fond of in particular are the Flektogon 20mm F2.8 and the Flek 35mm F2.4. These two lenses have very low distortion, especially the 20mm, they are MC (multi-coated) lenses so they have better light transmission and less flare than earlier models and the picture quality is impressive. Distortion will ALWAYS be a factor with any lens design but the better the lens maker, typically the less distortion there is. Zeiss for example was originally made in Germany, then they licensed the name and their recipes to manufacturers in other countries. Amazingly, altitude and atmospheric pressure seem to play a big role in lens quality. It's been discovered that lenses made high in the mountains of Germany, where the oxygen was lower, have less distortion and better overall image quality, than Zeiss lenses made in Japan closer to sea level. Go figure! One benefit I really like with my M42 lenses (older Tak's and Flek's) is that I can use an adapter and mount them both on my Pentax K5IIs AND a Nikon D800E. To me this is huge benefit to be able to work with the same lenses for two different formats and still be able to get incredible image results. In reality, crop sensor or FF doesn't really matter as much, it's the lens that makes the biggest difference IMO.

03-22-2013, 06:09 PM	#17
littledrawe Veteran Member Join Date: Jan 2010 Location: Red Rock Photos: Gallery \| Albums Posts: 2,514	How does the apparent increased magnification of the Q fit into all of this then?

03-22-2013, 06:44 PM	#18
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by littledrawe How does the apparent increased magnification of the Q fit into all of this then? Q has a 5.5x crop factor, but remember that's compared to full-frame. So compared to Pentax APS-C, which is believe is 1.54, that means a lens on the Q is 3.57x that of (say) a K-5. Now, most people are using adapted lenses on the Q for super-telephoto, but to keep in the realm of focal lengths we are used to seeing we might use a shorter length for example. So for instance, to get the FOV that you'd get from a 100mm on the K-5, you'd use a 28mm on the Q.

03-27-2013, 09:22 AM	#19
Yamanobori Veteran Member Join Date: Feb 2011 Photos: Gallery Posts: 573	The 90m is a 1.6X lens. Simply take the format diagonal and use it to divide the focal length. It is much easier to work in the format you are using than one you are not. BTW, that is 48mm in APS or 69mm in 35mm.