Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-31-2021, 11:33 AM - 1 Like   #76
Senior Member




Join Date: Feb 2021
Location: Hautes Pyrenees, France.
Posts: 121
QuoteOriginally posted by robgski Quote
The only problem is you might spend more time worrying about the lenses instead of using them and seeing if you like the results.
Less yapping, more snapping
..ls the right answer.

08-31-2021, 12:13 PM   #77
New Member




Join Date: Aug 2020
Photos: Gallery
Posts: 13
I have used APSC, but most FF lenses for more than 15 years, the first many years on APSC crop cameras. From my experience, there are no issues with flare and ghosting, and no issues with anything else. Because you only use 2/3 of the image circle, you get sharper sides and corners on the vast majority of lenses. Of course, you miss the lens' unique expression on FF. Look at an MTF chart, it is often about 2/3 out that the curves roll off.
08-31-2021, 02:08 PM   #78
Site Supporter
Site Supporter
RobA_Oz's Avatar

Join Date: Nov 2008
Location: Tasmania, Australia
Photos: Gallery
Posts: 8,182
QuoteOriginally posted by Lloyd_Christmas Quote
Hi all,
I'm curious about any negative effects of using full frame lenses on APS-C body.
Since the image circle is larger where it hits the sensor, is there extra light perhaps reflecting/bouncing around?
I don't notice anything so perhaps this is negligible.
Anyway, just curious..
Those who talk about people “worrying” about this issue, should re-read the original post (above). “Curious” isn’t “worrying”.

I think by now the matter of the larger image circle creating stray light that may affect image quality has been largely addressed, but three of us have noted the more significant issue of lower contrast caused by rear-element reflection on some older lenses, so continuing to harp on with posts basically saying “Well, I haven’t noticed anything, so there can’t be a problem” only serves to point out that many people don’t read through threads before posting.

08-31-2021, 02:14 PM   #79
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,442
QuoteOriginally posted by RobA_Oz Quote
Those who talk about people “worrying” about this issue, should re-read the original post (above). “Curious” isn’t “worrying”.

I think by now the matter of the larger image circle creating stray light that may affect image quality has been largely addressed, but three of us have noted the more significant issue of lower contrast caused by rear-element reflection on some older lenses, so continuing to harp on with posts basically saying “Well, I haven’t noticed anything, so there can’t be a problem” only serves to point out that many people don’t read through threads before posting.

But is that an FF vs APS-c issue? It's hard to imagine that it would happen on FF but not APS-c. Maybe we did understand it. We just didn't think it was relevant. When the question is "what problems are there with older lenses?" jump right in.

08-31-2021, 03:04 PM - 1 Like   #80
Veteran Member
Eyewanders's Avatar

Join Date: Jan 2008
Location: Land of the Salish Sea
Photos: Gallery | Albums
Posts: 3,343
This is a typical PF conjecture and circle-talk thread.

QuoteOriginally posted by Lloyd_Christmas Quote
Hi all,
I'm curious about any negative effects of using full frame lenses on APS-C body.
Since the image circle is larger where it hits the sensor, is there extra light perhaps reflecting/bouncing around?
I don't notice anything so perhaps this is negligible.
Anyway, just curious..
The answer is found in the question.
Negligible. At best.
They're larger. That's it. Go use them more. You'll see.
08-31-2021, 03:21 PM   #81
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,442
QuoteOriginally posted by Eyewanders Quote
This is a typical PF conjecture and circle-talk thread.



The answer is found in the question.
Negligible. At best.
They're larger. That's it. Go use them more. You'll see.
The PF MO. I you don't know, speculate.
08-31-2021, 04:17 PM - 2 Likes   #82
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,161
The succinct answer is, "No there isn't any discernable negative to using FF glass on a crop sensor outside of weight and size and possibly cost."

The more complex answer is "In theory there may be a chance for some additional flare etc. However most users have never seen this in practice."


Proving a negative is essentially impossible, all we can really do is say how it is statistically unlikely based on the number of non-events we collectively have experienced. On a related but different note: I personally have had one full frame lens flare badly when adapted - and it was on a full frame camera. The takumar 135 f2.5 bayonet is not known for being superb... and the coatings are not the best. But in my case I think what I experienced was sensor reflection. It probably could have happened in the same composition and location on my Pentax K-3 or KP, but perhaps it was specific to the Sony A7rII sensor stack.

08-31-2021, 04:34 PM - 1 Like   #83
Site Supporter
Site Supporter
RobA_Oz's Avatar

Join Date: Nov 2008
Location: Tasmania, Australia
Photos: Gallery
Posts: 8,182
QuoteOriginally posted by normhead Quote
But is that an FF vs APS-c issue? It's hard to imagine that it would happen on FF but not APS-c. Maybe we did understand it. We just didn't think it was relevant. When the question is "what problems are there with older lenses?" jump right in.
I’m with you on the FF vs APS-C issue, as far as the bodies are concerned.

Nonetheless, the OP’s opening statement expressed general curiosity about any negative effects of using FF lenses on APS-C bodies, before going on to the specific matter of the image circle. The fact that the rear-element reflection issue occurs with some older (and of necessity, FF) lenses doesn’t exclude noting them from a response. Maybe it’s a fine point. Anyway, I think we’ve covered everything the OP was asking about, and maybe a bit more.
09-01-2021, 02:36 AM   #84
SFX
Junior Member




Join Date: Jun 2013
Posts: 32
No issues at all. I use both Pentax Full Frame body & lenses and APS-C body & lenses (10mm till 500mm) by each other.
09-02-2021, 07:53 AM   #85
Veteran Member




Join Date: Jul 2018
Posts: 505
QuoteOriginally posted by Henrico Quote
3. FF's on APS-C deliver better IQ because the bigger sweet spot.
Not necessarily, as APS-C pixel size is generally smaller. At a given print size, lack of central sharpness or LoCA may be more noticeable on APS-C than on FF
09-02-2021, 08:13 AM   #86
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,161
QuoteOriginally posted by Dan Paris Quote
Not necessarily, as APS-C pixel size is generally smaller. At a given print size, lack of central sharpness or LoCA may be more noticeable on APS-C than on FF
That isn’t at all lens related however. The question is not what’s better about using a FF lens on FF but what if any downside exists to using a FF Lens on APSC. taking the same focal length APSC lens as the FF one in your example and taking an image offers no advantage over the FF lens pertaining to your stated concerns. In fact the apsc lens is likely to have more vignetting and weaker corners due to the way lenses perform. The concerns you stated are sensor related only. Also to be fair pixel pitch is more varied now than in the past. I can shoot a 16mp apsc sensor that has a larger pixel pitch than a full frame 61mp sensor for example.
09-02-2021, 08:57 AM - 1 Like   #87
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,442
^ plus one

It's amazing how many people just want to jump in and say "FF is better" even when no one is actually discussing that.
09-02-2021, 07:02 PM   #88
New Member




Join Date: Aug 2021
Location: Elkton, MD
Posts: 2
QuoteOriginally posted by othar Quote
The native lens hoods of FF lenses are too short for optimum performance on APS-C
A better way to think of this is that a longer lens hood could be used on a FF lens possibly yielding better results than the lens had on a FF when mounted on an APS/C. So, test it out with some black construction paper and tape!

Mike
09-03-2021, 08:18 AM   #89
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 40,442
QuoteOriginally posted by mikeporterinmd Quote
A better way to think of this is that a longer lens hood could be used on a FF lens possibly yielding better results than the lens had on a FF when mounted on an APS/C. So, test it out with some black construction paper and tape!

Mike
Given that no one has provided credible images showing the shorter lens hood is inadequate it would seem unlikely that one could actually produce different results. This is one of those situations where I say "Stop speculating, show me some images that prove your speculation."

My guess is that in 100 trials you won't be able to find a single image where there is ghosting or flare using a lens hood that is shorter than it needs to be. You might be able to produce a few with no lens hood, on some lenses, because many lenses like my FA 50 macro and Sigma 24 macro, effectively have the lens hood built into the lens. So we aren't even talking all lenses here, we are talking only about lenses with protruding front elements, and not ones with recessed front elements.

But that's what we need to know with any of these hypothetical differences. Does the phenomena what ever it is happen often enough to warrant remedial action? Until you know that, further discussion is meaningless. You have to establish there is a real world problem, before you start remedial practices to solve the problem.

The biggest problem, again based on my experience with ghosting and flare, is the sun is in the frame. It has little to do with the size of lens hoods.

Last edited by normhead; 09-03-2021 at 08:24 AM.
09-03-2021, 01:58 PM   #90
New Member




Join Date: Aug 2021
Location: Elkton, MD
Posts: 2
QuoteOriginally posted by normhead Quote
Given that no one has provided credible images showing the shorter lens hood is inadequate it would seem unlikely that one could actually produce different results. This is one of those situations where I say "Stop speculating, show me some images that prove your speculation."

My guess is that in 100 trials you won't be able to find a single image where there is ghosting or flare using a lens hood that is shorter than it needs to be. You might be able to produce a few with no lens hood, on some lenses, because many lenses like my FA 50 macro and Sigma 24 macro, effectively have the lens hood built into the lens. So we aren't even talking all lenses here, we are talking only about lenses with protruding front elements, and not ones with recessed front elements.

But that's what we need to know with any of these hypothetical differences. Does the phenomena what ever it is happen often enough to warrant remedial action? Until you know that, further discussion is meaningless. You have to establish there is a real world problem, before you start remedial practices to solve the problem.

The biggest problem, again based on my experience with ghosting and flare, is the sun is in the frame. It has little to do with the size of lens hoods.
Agree. Which is why I suggested a test with construction paper and tape if you really want to know. Pretty low cost way to test something.

... and a longer shade would allow you to put the sun that much closer, but yet outside of the image frame. Doesn't seem to be worth the trouble except in some special case.

Mike
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aps-c, darkroom, distance, dof, elements, enjoy, f/8, ff, focus, frame, frame lenses, glass, hood, images, issue, lenses, mask, photography, pity, post
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Full-frame vs. cropped lenses on APS-C camera Pentaxxoid Pentax SLR Lens Discussion 188 02-22-2021 06:43 AM
Some questions about buying sony full frame + adapters + pentax full frame lens jhlxxx Pentax Full Frame 7 06-14-2017 05:13 PM
Full frame or no full frame.... Deedee Pentax K-3 & K-3 II 14 10-08-2013 05:39 AM
Full Frame Full Frame vanchaz2002 Pentax DSLR Discussion 30 12-11-2008 07:09 AM



All times are GMT -7. The time now is 03:47 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top