[hrishi]

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8540tomg,

Mine snaps with the 900/8 were very similar to urs..

Good luck with tripod..
use remote release if possible..or timer if the subject is static..

[8540tomg]

Hrishi,

That is my plan. I have a remote and this is the time for it. I think any subject I photograph with this rig had better be static. It would take a miracle to get an image of a moving target. On the other hand I can get shots that would be impossible any other way. I any case I'm having fun!

Cheers,

Tom G

[danielchtong]

I took Daniel’s challenge and used the following combination of gear: Pentax K10, Pentax Rear Converter K T6-2X, and monopod in conjunction with my K 300mm f 4 lens. The 2x converts the K 300 to roughly a 900mm f8. Depth of field is non- existent with the 2x attached. Focusing is difficult and if you breathe heavily your subject disappears and dances out of the frame. I think my heartbeat knocked it around a bit too. As a result 99% of the shots were trash. I only spent half an hour and if time allowed I might have done better. In any case the three remaining shots were the best I could do today with this rig. The chickadees are a bit out of focus. The red wing blackbird is a little better. I like the bokeh in this shot. Not exactly ready for National Geographic are they Daniel? I’m not ready to concede it is impossible to get a good shot with this combo but it will be difficult. No post processing with any image. This is the way they came out of the K10. I think I might have better luck with the tripod. I’ll give that a go when I get some more time.

Hey Tom,
The first one works at least in theory. Likely Pentax Rear Converter K T6-2X is a better match to the 300F4. My Tamron/Kenko just won"t work at 1.5x (IMO only) . Lack of light and small DoF kills the whole thing as a birdie lens. In your case F8 is actually wide open at F4.
Judging from the shade of the first image, you have good light already.
I always push hard on the performance of my lens like doing portrait with long lens and shooting bird with fisheye. The whole thing is good exercise in furthering our knowledge and skill.
Keep posting and I look forward to more input from you

Daniel
edited later: use burst as the 2nd shot has less vibration shake than the first one. Just like using a remote

[Ben_Edict]

While looking for 300mm lenses on Fleabay, I found a listing for a collar that's supposed to work on this lens:
Support Collar for SMC Pentax 300 mm 1:4 ,FA 300 1:4.5 - eBay (item 230261061409 end time Jun-21-08 01:39:00 PDT)

The overseas shipping looks to be quite reasonable.

Heather (who's trying to resist the lure of this lens and a TC)

Heather, forget this "collar". I was dumb enough to buy one. It is made of plastic and a very soft one on top. So it bends and cannot give the support one would expect from a tripod collar. It is crap!

Ben

[clawhammer]

8540- The one thing that bugs me about the 200 f/2.5 is the super slow focusing- is the 300 f/4 similar?

[Ben_Edict]

8540- The one thing that bugs me about the 200 f/2.5 is the super slow focusing- is the 300 f/4 similar?

in one word: Yes.

All of these old telephoto lenses have nearly a full 360 degs. rotation from nearest to infinity. The problem is, that they don't have IF (internal focusing), but only focus by shifting the whole lens assembly away (for near distances) or towards (at infinite distances) the mount. The amount of travel required is directly connected to 1.) the focal length of the lens and 2.) the the minimum focusing distance. So telephoto lenses require much more travel and as such, need much more rotation.

One could implement steeper focusing threads, but this makes precise focusing very hard. So it might be much faster (and requieres more force) to get the rough focus, but fine focusing would be a more tedious and slower process, then.

Ben

[8540tomg]

Clawhammer,

The 300 f4 and 200 f 2.5 are similar in this regard. I've been using them so long I don't even think about focusing anymore. I have not found focusing to be an issue.


Tom G

[8540tomg]

Ben,

Thanks for the explanation of focusing on the K series teles. I was unaware of those details. This forum continues to amaze.

Daniel,

There may be some advantage to using the K T6 – 2X with the K 300. The fact it was designed for use with the K series telephoto lenses may be responsible. I had a Takumar 2x for a while and the K T6-2X works far better with the 300mm. I shot the birds at high noon as I find things get a little dim in the finder with this rig at most other times of day. Trying to manually focus in dimmer light would be too frustrating for me.

I’ll go back to the pond with the tripod later this week. If the birds cooperate I’m sure it will improve the results. Looking forward to some more K300 shots from you as well.

Cheers

Tom G

[clawhammer]

Thanks for the replies. Maybe now I have my excuse *not* to get the 300.... maybe....

[NaClH2O]

Heather, forget this "collar". I was dumb enough to buy one. It is made of plastic and a very soft one on top. So it bends and cannot give the support one would expect from a tripod collar. It is crap!

Ben

I have this collar and like it muchly. Yes it is plastic, but hard phenolic plastic and not soft at all. I've found the mount to be rock steady even in portrait orientation.

NaCl(maybe the manufacturer changed materials?)H2O

[Lowell Goudge]

why not use the 1.7x AF TC? I do, and it works very well with the 300mm F4.

I use this with my *istD for nature, along with a flash (*istD does TTL and can use old lenses for flash photography.

See first shot in the post below

https://www.pentaxforums.com/forums/106132-post4.html

for the tripod mount, please see attached post, I made it myself with 1/2 inch and 1 inch aliminum bar 1/8 inch thick. Lined ring with leather to protect the lens, and attached parts with rivits and epoxy.

https://www.pentaxforums.com/gallery/images/1116/1_100_2666__2_.JPG

[8540tomg]

Good looking mount Lowell! I think mine was milled out of 1/2 aluminum stock as well. It will never fall apart or worse still lose its grip on the lens.

Cheers

Tom G

[Mike.P®]

Just got a K mount 300mm that I won on Ebay.
Both taken hand held

At minimum focus:



At maximum focus with a Tamron 1.4X Teleconverter.

[8540tomg]

Hi Guys,

Went back to the pond between showers today with the K 300 and K T6-2X. Let's see what we got today. Used the tripod this time. Blackbirds were flitting all over the place and seldom stood still for a shot. This was the best of the day.



Dandelion



This rig requires a lot of patience. I found myself yearning for something in the more auto everything camp. On the other hand I can't afford that stuff at present.
Did notice some nasty purple fringing in shots where the bird was surrounded by branches.



In any case Daniel, if one is not too critical, the K 300 with a K T6-2X on the back end, when combined with infinite patience and more than a little skill MIGHT be able to produce a passable image. I'm not sure I've succeeded here but I still think it could be done.

Cheers,


Tom G

[Zewrak]

Uhm. That bird has no head.