Win a Pentax Limited Lens: Raffle Now Live!

barbutz221 · 05-01-2019, 02:44 AM

Hi guys, i just acquired the Tokina 17mm RMC and it has some horible color banding, now it might be the camera or or the lens it's just a bad copy? The camera is a Sony a7III.

Attached Images

View Picture EXIF

View Picture EXIF

**TwoUptons** · 05-01-2019, 03:39 AM

Is that reflection off the sensor onto the back of the lens and back?

I know that’s a thing for some lens/sensor combinations, but I don’t know how to confirm it...

-Eric

barbutz221 · 05-01-2019, 03:56 AM

It might be, I read a little bit as well about it, now the question is, cat it be fixed?

**BigMackCam** · 05-01-2019, 04:15 AM - **1 Like**

This looks to me like colour shift due to the angle of light hitting the Bayer filter of the sensor. I have a couple of lenses (Russar MP-2 and Jupiter-12) that do something very similar, both of which have rear elements that sit very close to the sensor. It's not something that can be fixed - it's just an interaction between the lens, and a medium that it was never designed for.

If you process your photos as B&W, more often than not the colour shift isn't a problem. That's what I do

PePe · 05-01-2019, 05:42 AM

I have one of these lenses, use it mostly with the K-1. Have not seen anything like this. As mentioned above, it looks like light rays not hitting the sensor at the right angle in the edges of the frame. Does anyone know whether the sensor/pixel arrangements of the K-1 and A7III sensors differ in this respect?

**BigMackCam** · 05-01-2019, 06:04 AM

Searching online, it looks like the lens should work just fine with the A7 series:

TOKINA RMC 17mm 1:3.5

Given that, it could be a problem with one or more elements in the lens, or possibly - but unlikely, I think - reflections as a result of the specific adapter.

Have you tried looking through the lens to see if all looks normal?

barbutz221 · 05-01-2019, 06:52 AM

Just looked through the lens, with the naked eye I can still see the halo, it's like the coating was affected by something, think i will try and clean it, should i use some sensor cleaning liquid or some high grade cleaning alcohol?

barbutz221 · 05-01-2019, 08:39 AM

Same effect after the cleaning as well...

**BigMackCam** · 05-01-2019, 09:05 AM

That almost looks like a cemented group is delaminating...

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: Tokina RMC 17mm 3.5	krazykat	Sold Items	6	07-24-2018 07:49 PM
For Sale - Sold: Tokina RMC 17mm f/3.5 Lens – Pentax K Mount, Full Frame (Price Drop)	c.a.m	Sold Items	6	02-20-2018 06:08 PM
Tokina 17mm f3.5 RMC	-spam-	Pentax SLR Lens Discussion	4	10-23-2007 09:45 AM

05-01-2019, 03:39 AM	#2
TwoUptons Loyal Site Supporter Join Date: Nov 2015 Photos: Albums Posts: 4,225	Is that reflection off the sensor onto the back of the lens and back? I know that’s a thing for some lens/sensor combinations, but I don’t know how to confirm it... -Eric

05-01-2019, 03:56 AM	#3
barbutz221 New Member Join Date: May 2019 Posts: 4 Original Poster	It might be, I read a little bit as well about it, now the question is, cat it be fixed?

05-01-2019, 04:15 AM - 1 Like	#4
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,701	This looks to me like colour shift due to the angle of light hitting the Bayer filter of the sensor. I have a couple of lenses (Russar MP-2 and Jupiter-12) that do something very similar, both of which have rear elements that sit very close to the sensor. It's not something that can be fixed - it's just an interaction between the lens, and a medium that it was never designed for. If you process your photos as B&W, more often than not the colour shift isn't a problem. That's what I do

05-01-2019, 05:42 AM	#5
PePe Pentaxian Join Date: Nov 2007 Location: Helsinki, Finland Photos: Gallery \| Albums Posts: 597	I have one of these lenses, use it mostly with the K-1. Have not seen anything like this. As mentioned above, it looks like light rays not hitting the sensor at the right angle in the edges of the frame. Does anyone know whether the sensor/pixel arrangements of the K-1 and A7III sensors differ in this respect?

05-01-2019, 06:04 AM	#6
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,701	Searching online, it looks like the lens should work just fine with the A7 series: TOKINA RMC 17mm 1:3.5 Given that, it could be a problem with one or more elements in the lens, or possibly - but unlikely, I think - reflections as a result of the specific adapter. Have you tried looking through the lens to see if all looks normal?

05-01-2019, 06:52 AM	#7
barbutz221 New Member Join Date: May 2019 Posts: 4 Original Poster	Just looked through the lens, with the naked eye I can still see the halo, it's like the coating was affected by something, think i will try and clean it, should i use some sensor cleaning liquid or some high grade cleaning alcohol?

05-01-2019, 09:05 AM	#9
BigMackCam Digitiser of Film Join Date: Mar 2010 Location: North East of England Posts: 20,701	That almost looks like a cemented group is delaminating...

Tokina 17mm RMC fd mount, Bad copy?

Win a Pentax Limited Lens: Raffle Now Live!