BirdForum

BirdForum (https://www.birdforum.net/index.php)
-   Kowa (https://www.birdforum.net/forumdisplay.php?f=298)
-   -   Kowa 884 with Sony A7r - Very Soft Focus (https://www.birdforum.net/showthread.php?t=393158)

socratic Friday 14th August 2020 01:42

Kowa 884 with Sony A7r - Very Soft Focus
 
Hello all, just registered on this forum. I am new to digiscoping but wanted to augment my tools for photographing wildlife from a distance. I picked up a used 884 and purchased the adapters necessary for my Sony A7r. I have spent the last couple of days testing out the scope and having a heck of a time getting focus. I do have focus assist on the camera turned on. Have tried shutter speeds from 1/30 all the way up to 1/2000 and ISO of 100 all the way up to 20000!!! I just can't see anything really sharp at various settings from 20x all the way up to 60x (very tough getting enough light for anything above 35x or so). I use a video tripod and head that is probably overkill, but wanted to be sure not to blur by shake....also use remote trigger. Am I missing something? Am I expecting too much from the scope? Or could the scope be out of calibration? Or something else? Any suggestions very much appreciated. Jim

jring Friday 14th August 2020 08:07

Hi,

first of all, welcome to birdforum!

Do you have an eyepiece for the scope? If yes, do you get an easy to find point of best focus at 60x? You could also do a star test then and see if the glass is good.

Depending on how you digiscope, getting a good focus manually can take some practice and certainly needs help like focus peaking and a magnification function.

You said you have a remote trigger - that is a good idea. As for a tripod being overkill for a digiscoping setup - that is rarely the case.

But questions on how to get good images are best asked in the digiscoping forum - in here it's all about optics.

Joachim

mayoayo Friday 14th August 2020 11:23

Welcome to the forum.. The Digiscoping forum, as Joachim pointed, would provide more answers and advice.. For what is worth, even excellent scopes and good digiscoping cameras,get best results working at close range and low magnification

socratic Friday 14th August 2020 15:14

Thanks to both of you for your advice. Will re-post in the other forum and see if anyone has suggestions.

jring Friday 14th August 2020 17:17

Hi,

do you have an eyepiece to test the scope alone?

Joachim

socratic Friday 14th August 2020 17:23

Yes, I have a 20-60 Kowa Zoom that seems (to my eye) to be sharp as a tack. Only when I use my A7r do I see softness. I fugured I simply had some setting like APS-C vs full frame in wrong mode, but have checked that along with almost any setting that can affect the focus issue. :(

mayoayo Saturday 15th August 2020 14:52

I read recently that the AR7 IV needed specific lenses in order to take advantage of the resolution of the sensor, and that the camera was developed around specific lenses to avoid field curvature etc etc.. I don't know what model camera you have or if the full size sensor resolution can be the matter here.. I am sure in the digiscoping forum you will find more answers.. I will be interested in the subject..
Regards

socratic Saturday 15th August 2020 15:59

2 Attachment(s)
Ran this optics test to see the difference between my Sony 70-200 zoom lens and the 20-60 zoom with the 884. In order to match up the size of the two targets, I had crop the Sony image - probably 300-400x normal. I did do some touch up with contrast and exposure to get each as crisp as I could. Resizing for this platform could incorrectly show difference. Guess I will look after post. Could be that I am simply expecting too much from the scope? Took a look, pretty good representation. The Sony is the small of the two photos.

Vollmeise Friday 25th September 2020 09:05

Socratic, could you post a picture of your setup here (scope with camera mounted)? I'm sure there will be some ideas just from takeing a look at that.

Cheers

socratic Saturday 26th September 2020 14:22

I actually gave up on getting good results and picked up a Sony 200-600 zoom lens. I had been using the Kowa T and camera adapter directly connected to the scope. I haven't had a chance to use the Sony lens yet other than testing it out, so don't have any comparisons, but the extra couple of stops coupled with faster focus options and better portability influenced the purchase. I imagine will be getting about the same sharpness as some have squeezed out of the Kowa Scopes, but for me, this might be a better option. I'll post a few shots when I get some.


All times are GMT. The time now is 14:34.

Powered by vBulletin®, copyright ©2000 - 2020 vBulletin Solutions, Inc.
BirdForum Ltd 2002 - 2018