Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-01-2016, 01:30 AM   #1
New Member




Join Date: May 2016
Posts: 5
Micro Contrast and Corner Sharpness difference between 645 35mm A 3.5 MF and HD

Hi,


Does anyone here had the chance to compare the Micro Contrast and Corner Sharpness between the old 645 35mm A 3.5 MF and new HD PENTAX-D HD FA 645 35mm F3,5 AL [IF] ?

I actually don't need Autofokus and the MF version of this lens is very affordable.


Thank you in advance for your help!

05-01-2016, 02:02 AM   #2
Senior Member




Join Date: Feb 2014
Posts: 111
Sample files here for each lens: https://www.pentaxforums.com/forums/48-pentax-medium-format/312720-testing-35mm-options-4.html

You can do your own comparison.
05-01-2016, 04:10 AM   #3
Joa
New Member




Join Date: May 2016
Posts: 5
Original Poster
Thanks a lot!

Do you know what focal you get if you adapt the Pentax 645 35mm FA to a Canon Full Frame Body?

---------- Post added 05-01-16 at 04:17 AM ----------

sorry, I meant focal lenght.
05-01-2016, 04:37 AM   #4
Senior Member




Join Date: Oct 2013
Photos: Gallery | Albums
Posts: 157
oh dear, with this question you open the pandoras box on this forum...

the noted focal length on lenses always(?) refers to the focal length a full frame body would make use of[*]. In your case that would simply mean the 35mm will stay a 35mm on a full frame body[*].

However the 35mm on a medium format camera would exercise a much wider field of view, which would equal a fraction of the focal length on a full frame body. I believe the ratio for focal length conversion from full frame body to a medium format is about .75 if i am not mistaken. but i am sure somebody can help out

[*] with its respective field of view


cheers,

05-01-2016, 05:08 AM   #5
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 10,872
QuoteOriginally posted by Joa Quote
Do you know what focal you get if you adapt the Pentax 645 35mm FA to a Canon Full Frame Body?
The lens is 35mm, so if you put it on a certain camera, it will look like all other 35mm lenses will look on that camera. However, the field of view will be different depending on the camera - 35mm on 645 camera is really wide angle; on FF it is medium wide; on APSC it is normal.
You can easily adapt from a bigger format down, but not necessarily the other way around, just because the smaller format lenses have a smaller image circle, so you would end up with dark corners on a larger format camera.

That said, adapting 645 lenses to other formats can have its problems. For example, lack of automation, loss of contrast (because so much light is bouncing around inside of the camera), and so on. Usually medium format lenses get adapted to APSC or FF format with tilt/shift adapters. Otherwise, it generally makes more sense to buy a smaller lens that is made, optimized, for the format that you want to use it on
05-01-2016, 05:33 AM   #6
Joa
New Member




Join Date: May 2016
Posts: 5
Original Poster
Yes, thank you, I was aware of that, my intention is to use it as a tilt/shift, just wasn't sure how wide it would be on my Canon 5D MKII.
05-01-2016, 02:05 PM   #7
Site Supporter




Join Date: Mar 2016
Location: La Vienne (86), France
Posts: 151
QuoteOriginally posted by Joa Quote
Yes, thank you, I was aware of that, my intention is to use it as a tilt/shift, just wasn't sure how wide it would be on my Canon 5D MKII.
You'd get 54.4 degrees horizontally and 37.8 degrees vertically......exactly the same as a 35mm lens from Canon or Zeiss.

Bob
05-01-2016, 04:20 PM   #8
Senior Member




Join Date: Feb 2014
Posts: 111
QuoteOriginally posted by Joa Quote
Ymy intention is to use it as a tilt/shift..
What adapter will you use?

05-01-2016, 10:40 PM   #9
Joa
New Member




Join Date: May 2016
Posts: 5
Original Poster
Really?

I always thought it should be wider? Why does a 35mm lens on APSC built for APSC cover a more narrow field of view on APSC than a 35mm lens built for full frame on full frame? Wouldn't a 35mm medium format also cover a wider field of view on full frame than a 35mm full frame lens on full frame?

---------- Post added 05-01-16 at 11:10 PM ----------

QuoteOriginally posted by Joa Quote
Really?

I always thought it should be wider? Why does a 35mm lens on APSC built for APSC cover a more narrow field of view on APSC than a 35mm lens built for full frame on full frame? Wouldn't a 35mm medium format also cover a wider field of view on full frame than a 35mm full frame lens on full frame?
I was planning on using a kenko shift adapter. Thought that might have an effect on the field of view like a 21mm ring.
Kipon shift Pentax 645 P645 mount lens to Canon EOS EF adapter 5D II III 6D 700D | eBay
05-02-2016, 02:47 AM   #10
Pentaxian




Join Date: Apr 2014
Location: Baltimore
Posts: 557
QuoteOriginally posted by Joa Quote
Really?

I always thought it should be wider? Why does a 35mm lens on APSC built for APSC cover a more narrow field of view on APSC than a 35mm lens built for full frame on full frame? Wouldn't a 35mm medium format also cover a wider field of view on full frame than a 35mm full frame lens on full frame?

---------- Post added 05-01-16 at 11:10 PM ----------


I was planning on using a kenko shift adapter. Thought that might have an effect on the field of view like a 21mm ring.
Kipon shift Pentax 645 P645 mount lens to Canon EOS EF adapter 5D II III 6D 700D | eBay
Well, for use as a T/S it's the image circle that's key. You ought to have plenty with this lens, as it was designed for (oh, boy, here we go....) FF 645. How it looks in terms of FOV is another matter---there's a handy table on this website you can find here
05-02-2016, 05:58 AM   #11
Joa
New Member




Join Date: May 2016
Posts: 5
Original Poster
Thanks everyone, but it seems there are a lot of different views regarding this issue I was hoping to get a 21mm tilt shift for my Canon since the Canon 24mm TSE II is too narrow for my needs and the 17mm to wide. Would have loved to get something in between those two for a bargain price.
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!
24x36mm, 35mm, 645d, 645z, adapter, apsc, camera, contrast, contrast and corner, corner, field, format, frame, full-frame, hd, lens, medium, medium format, mf, pentax, pentax 645 35mm, sharpness, shift, view
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Difference between 645 FA and DFA lenses? prohtex Pentax Medium Format 12 09-27-2015 01:39 AM
Difference Between 21mm HD and DA Non HD rollsman4 Pentax SLR Lens Discussion 21 05-15-2015 05:12 PM
A difference between K-5 and K-3 retention of aperture or shutter speed settings at p MNCurt-K10D Pentax DSLR Discussion 10 04-21-2015 03:08 PM
What's the difference between Unsharp mask and sharpness & blur? Dewman Digital Processing, Software, and Printing 4 07-27-2014 06:13 AM
How much of a difference between 2.8 and 3.5 epqwerty Pentax SLR Lens Discussion 16 04-21-2010 01:00 AM



All times are GMT -7. The time now is 10:36 PM. | 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