Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-05-2018, 07:24 PM   #1
New Member




Join Date: Jul 2018
Posts: 5
Hey everyone! And a question about manual focal length input?

Hey everybody! I'm new as you can til. I just started getting serious into photography, And I was attracted to the Pentax cameras because of their internal shake reduction, I thought most cameras companies had internal shake reduction build-in to their bodies but, I guess that isn't so. LoL! Having purchases a G7 micro 4/3 and a 500mm mirror lens with a rickety tripod didn't yield many good moon photo sorry to say. Now that I have a Pentax K-50 I'm at least able to take shots hand held with the mirror lens, The 500mm bower lens came with a 2X converter which turns the mirror lens to 1000mm lens. My dilemma is my manual focal length input only go to 800mm so I've been leaving it at 500mm on the manual input thinking half of 1000mm is 500. Can anyone guild me on what the manual focal input does and doesn't do.

Here a photo I took with my 500mm mirror lens.

Attached Images
View Picture EXIF
PENTAX K-50  Photo 
07-05-2018, 08:44 PM - 1 Like   #2
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 49,705
Setting it as close to 1000mm as possible would deliver optimal results, so you can safely go for 800mm.

However I have a hunch the image quality would be just as good (if not better) at 500mm, without the 2x

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

07-05-2018, 11:13 PM - 1 Like   #3
pjv
Otis Memorial Pentaxian
Moderator
Loyal Site Supporter
pjv's Avatar

Join Date: Mar 2015
Location: Melbourne, Australia
Photos: Gallery
Posts: 7,286
Hi, and welcome aboard.
07-06-2018, 12:01 AM - 1 Like   #4
Site Supporter
Site Supporter




Join Date: Oct 2017
Location: Lancaster
Photos: Gallery
Posts: 1,822
Hi, welcome nice picture. I have a mirror lens but so far it has defeated me. I agree with what Adam said about the tc. It shortens your dof alarmingly and decreases the light on what is already a medium to small aperture (mine is f8). If you are going to do much manual focus you could try a Pentax magnifying eyepiece. The magnification is not huge but it makes a big difference.

07-06-2018, 12:19 AM - 2 Likes   #5
PJ1
Site Supporter
Site Supporter
PJ1's Avatar

Join Date: Jul 2012
Location: Mosquito Creek, Australia
Photos: Gallery | Albums
Posts: 4,400
Welcome to the Forums. Putting it simply, the "in body" SR responds to the movement of the camera body. As the effect of movement will be magnified at longer focal lengths, it is necessary to input the focal length so the camera knows how much to compensate. However, if you are using the camera on a very steady tripod, it may be best to switch the SR off and use a 2 second shutter delay so your camera is still when the shutter fires. Adam's advice about not using the TC is probably the way to go. Just compare your results with and without the TC and see what the result is.
07-06-2018, 01:53 AM - 1 Like   #6
Loyal Site Supporter
Loyal Site Supporter
twilhelm's Avatar

Join Date: Feb 2009
Location: Florida
Photos: Gallery | Albums
Posts: 2,355
Welcome to the forum! They’ve already covered the SR advice, so enjoy your time here.
07-06-2018, 04:39 AM - 1 Like   #7
smf
Loyal Site Supporter
Loyal Site Supporter
smf's Avatar

Join Date: Feb 2008
Location: Midland, MI
Photos: Gallery | Albums
Posts: 4,033
Welcome and best wishes.
07-06-2018, 05:39 AM - 1 Like   #8
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 17,442
What is the subject of your shot?

07-06-2018, 11:40 AM - 1 Like   #9
PEG Moderator
Loyal Site Supporter
Kerrowdown's Avatar

Join Date: Aug 2008
Location: Hielands o' Scootlund
Photos: Gallery
Posts: 50,125
As usual I'm late to the party... so I'll just say welcome to the forum.
07-06-2018, 01:41 PM - 1 Like   #10
Loyal Site Supporter
Loyal Site Supporter
Mikesul's Avatar

Join Date: Sep 2009
Location: Phoenix, AZ
Posts: 6,472
Welcome and great introductory photo! Keep them coming.
07-09-2018, 04:49 AM   #11
New Member




Join Date: Jul 2018
Posts: 5
Original Poster
QuoteOriginally posted by UncleVanya Quote
What is the subject of your shot?
mostly the moon at night
07-09-2018, 06:15 AM   #12
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 17,442
QuoteOriginally posted by jonnie_webb Quote
mostly the moon at night
I was asking about the shot you posted early in the thread. If that's the moon I'm really confused. Lol. I would love to see how the moon shots turn out though.
07-09-2018, 11:55 PM   #13
New Member




Join Date: Jul 2018
Posts: 5
Original Poster
QuoteOriginally posted by UncleVanya Quote
I was asking about the shot you posted early in the thread. If that's the moon I'm really confused. Lol. I would love to see how the moon shots turn out though.
That photo was a 500mm mirror lens close-up of the Legion of Honor fountain, A museum in San Francisco CA. USA
07-10-2018, 07:21 AM   #14
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 17,442
QuoteOriginally posted by jonnie_webb Quote
That photo was a 500mm mirror lens close-up of the Legion of Honor fountain, A museum in San Francisco CA. USA
It is fascinating and abstract in this context.
07-30-2018, 11:52 AM   #15
Junior Member




Join Date: May 2014
Photos: Albums
Posts: 36
Welcome to the forums. Stay away as much as possible from a low-budget 2X, and put the money on a steady tripod. Have fun !
Reply
« Nature | Hello »

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!
1000mm, 500mm, cameras, input, length, lens, mirror, pentax, photo, reduction
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K mount adapter, focal length input question NoCo Pentaxian Pentax Q 2 04-03-2018 02:41 PM
Manual Focal Length Input WhichWayIsUp? Troubleshooting and Beginner Help 11 12-15-2016 05:32 AM
Input focal length with a manual not prime Amcsorley Troubleshooting and Beginner Help 12 01-09-2016 08:35 AM
SR Focal Length Input for a Manual Zoom Lens? frank Pentax SLR Lens Discussion 13 03-15-2009 03:04 PM
Input focal length for a manual lens jpzk Photographic Technique 11 01-14-2009 08:50 PM



All times are GMT -7. The time now is 07:38 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