Half Frame's under exposed

DDampney · 08-24-2020, 08:26 PM

Hi, I've got an old Pentax 67, that I've had consistent results with over the years but for some reason after not having used it for awhile, I'm now finding that a large proportion of my the right side of my frames are totally underexposed. See attached.

Attached Images

View Picture EXIF

Silent Street · 08-24-2020, 11:01 PM

Have you ruled out developing faults such as loading on the reel for processing/uneven development?
This wouldn't apply as a consideration if your negatives are processed by a lab.

Otherwise, the possibility of shutter curtain drag during the exposure — only exposing part of the film and not of the other.

It is not light piping, which would manifest as a bright streak from the extremities of the film.

Inaccurate shutter speed might be an issue. Have shutter speeds been checked as correct? I would like to see another roll exposed at each marked shutter speed rather than pass judgement on one sample only.

Jonathan Mac · 08-25-2020, 04:07 AM - **1 Like**

Looks like shutter capping, where the two curtains don't both move at the right speed and exposure is therefore unequal across the frame. Usually happens (or at least starts) at higher shutter speeds. If it were a development problem I'd expect there to be differences between the top and bottom of the frame rather than one side and the other.

stevebrot · 08-25-2020, 09:13 AM

I vote shutter capping.

Steve

MikeMcE · 08-25-2020, 05:24 PM

I suspect it was left in the set position and as noted above the curtains aren't traveling at the proper speeds. Time for a tuneup and retensioning.

You can see this when you set too fast of shutter speed using flash, partial frame exposure. Higher speeds are caused by a "slit" traveling across the plane. narrower slit width equals faster speeds. due to this both curtains have to have tensions set properly to maintain consistant width for equal exposure across the entire plane.

DDampney · 08-26-2020, 02:56 PM

Hi guys, I so appreciate your feedback! It's shutter capping for sure. One of the other key indicators that you guys mentioned is that its significantly more apparent at higher shutter speeds.

Now for my next question:

I live in Ulladulla on the New South Wales South Coast (4 hours south of Sydney). I'm wondering where I'd send my camera in for a tune up? And how much I'd expect to pay? OK that was two questions!

Thanks again!

Dean

Silent Street · 08-26-2020, 05:25 PM

Originally posted by DDampney

I live in Ulladulla on the New South Wales South Coast (4 hours south of Sydney). I'm wondering where I'd send my camera in for a tune up? And how much I'd expect to pay? OK that was two questions!

Lynchpin (https://www.pentaxforums.com/forums/private.php?do=newpm&u=124943) here on pentaxforums, a resident of Adelaide, has had his P67 examined by a tech somewhere. PM him to get details. The other place might be VinTech in Melbourne/Victoria (03) 9602 1820, Level 5, 358 Lonsdale Street. Whoever and wherever the camera goes, avoid sending your camera by post at this time: use road freight: Australia Post is having an appalling game getting mail to go anywhere, on time or delivered at all. I'm still waiting on two letters posted in Melbourne 2 weeks ago!!!

08-26-2020, 02:56 PM	#6
DDampney New Member Join Date: Aug 2020 Posts: 2 Original Poster	Gratitude and.....One Further Question Hi guys, I so appreciate your feedback! It's shutter capping for sure. One of the other key indicators that you guys mentioned is that its significantly more apparent at higher shutter speeds. Now for my next question: I live in Ulladulla on the New South Wales South Coast (4 hours south of Sydney). I'm wondering where I'd send my camera in for a tune up? And how much I'd expect to pay? OK that was two questions! Thanks again! Dean

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
K70 images under exposed when using ND or polarizer.	J. Lee	Visitors' Center	9	04-16-2020 05:04 PM
Full frame vs half frame	Paul Charlier	Pentax K-1 & K-1 II	13	06-28-2019 04:12 AM
Every shot under exposed, K-S1	gvguy	Repairs and Warranty Service	6	02-02-2019 04:45 AM
cloudy day setting/ under exposed?	KPsplash	Troubleshooting and Beginner Help	3	06-29-2017 03:39 AM
K-50 Live View vs Viewfinder (Viewfinder photos Under exposed)	jackloganbill	Pentax K-30 & K-50	11	06-10-2016 08:01 AM

08-24-2020, 11:01 PM	#2
Silent Street Veteran Member Join Date: Nov 2011 Location: Castlemaine, Victoria, AUS Photos: Albums Posts: 1,151	Have you ruled out developing faults such as loading on the reel for processing/uneven development? This wouldn't apply as a consideration if your negatives are processed by a lab. Otherwise, the possibility of shutter curtain drag during the exposure — only exposing part of the film and not of the other. It is not light piping, which would manifest as a bright streak from the extremities of the film. Inaccurate shutter speed might be an issue. Have shutter speeds been checked as correct? I would like to see another roll exposed at each marked shutter speed rather than pass judgement on one sample only.

08-25-2020, 04:07 AM - 1 Like	#3
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Looks like shutter capping, where the two curtains don't both move at the right speed and exposure is therefore unequal across the frame. Usually happens (or at least starts) at higher shutter speeds. If it were a development problem I'd expect there to be differences between the top and bottom of the frame rather than one side and the other.

08-25-2020, 09:13 AM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	I vote shutter capping. Steve

08-25-2020, 05:24 PM	#5
MikeMcE Pentaxian Join Date: Jun 2020 Photos: Albums Posts: 1,093	I suspect it was left in the set position and as noted above the curtains aren't traveling at the proper speeds. Time for a tuneup and retensioning. You can see this when you set too fast of shutter speed using flash, partial frame exposure. Higher speeds are caused by a "slit" traveling across the plane. narrower slit width equals faster speeds. due to this both curtains have to have tensions set properly to maintain consistant width for equal exposure across the entire plane.

08-26-2020, 05:25 PM	#7
Silent Street Veteran Member Join Date: Nov 2011 Location: Castlemaine, Victoria, AUS Photos: Albums Posts: 1,151	Originally posted by DDampney I live in Ulladulla on the New South Wales South Coast (4 hours south of Sydney). I'm wondering where I'd send my camera in for a tune up? And how much I'd expect to pay? OK that was two questions! Lynchpin (https://www.pentaxforums.com/forums/private.php?do=newpm&u=124943) here on pentaxforums, a resident of Adelaide, has had his P67 examined by a tech somewhere. PM him to get details. The other place might be VinTech in Melbourne/Victoria (03) 9602 1820, Level 5, 358 Lonsdale Street. Whoever and wherever the camera goes, avoid sending your camera by post at this time: use road freight: Australia Post is having an appalling game getting mail to go anywhere, on time or delivered at all. I'm still waiting on two letters posted in Melbourne 2 weeks ago!!!