Last edited by tsjanik; 16th June 2013 at 15:31.
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Taken with the FA 75mm lens.
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How can I get a copy of your 645 lens reviews? I thought I had printed one out, but then came Sandy, and we were homeless for 6 months, and I lost or misplaced it. I just purchased a used 400 mm FA f5.6 lens. What was your opinion of that lens. I also have the 1.4x extender designed for the 300 mm f4 manual focus lens, which I also have, but I assume I can also use it with the 400? Be interesting to compare the 400 mm to the 300 mm plus 1.4x. Any thoughts? Thanks as always
Dave in NJ
Just caught your two most recent postings. Glad you found my comprehensive lens review for Pentax 645 lenses used on the 645D and congrats on the purchase of the FA 400 f5.6 lens.
I am of two minds when it comes to the FA 400 f5.6 645 lens and not in total agreement with digiloyd.
When taken by itself, it is an extremely fine lens (prefaced that one obtains a good sample). It most certainly benefits from stopping down from max. aperture and I can readily see the improvements in sharpness and resolution across the frame when used at f8 and especially f11. It's not a lens I would use often at f5.6 and depending on the situation, might start at f8 for my purposes. Keep in mind I expect a lot from long telephoto's such as this one and the FA 300 f4 645 lens often using many of the exceptional long telephoto's by Nikon. Although the lens is useable at f5.6, for prints, espcially larger ones, I have found it mandatory to stop down as described.
The FA 300 f4 645 lens I feel is notable and exceptional performer and one that most definitely deserves acclaim. When shot wide open at f4 the image quality is already quite impressive and although it does benefits from stopping down to f5.6 and even f8, f4 is most certainly usable for output to moderately sizable print.
The FA 400 f5.6 has the advantage of a longer focal length while the FA 300 f4 has the advantage of being a faster lens that can optically surpass the FA 400 f5.6 at wider apertures.
As for the question regarding use of the 1.4x with either lens, I've made some preliminary attempts but nothing formal. If it's a case of useing the Fa 300 f4 + 1.4x vs. the FA 400 f5.6 without a converter, I'd probably opt for the straight use of the FA 400 f5.6. It's not that the Fa 300 f4 doesn't do well with the 1.4x, it just that quite a bit of stopping down the lens is necessary.
I wasn't satisfied with the 1.4 on the FA 400 f5.6, but then again I expect a lot in terms of performance.
One things for certain, in the case of both these lenses, Af fine tune on the 645D is mandatory and makes a substantial difference in performance when used at the best setting possible.
*** As a side note Dave, I just sent you a PM.
Thanks Dave. I only have one FA lens, the excellent 45-85, so I have never attempted to fine tune the focus ( don't even know how to do it). Now that I will have two FA lenses, I should probably learn how to do it. As your review says, the 45-85 is a real winner. It constantly makes outstanding 24"x 32" prints. I use it usually around f11 to f13 for seascapes, usually with a monopod. All my other lenses are manual focus A lenses: 35mm, 75 mm, 120 macro, 150 mm, 200 mm, and 300 mm. I agree with you: at the give away prices for a used 75mm lens ( especially the MF version), this is a real gem. Small, light and mine is very sharp at small apertures which I use. I always enjoy your postings. We all thank you.
Dave, thanks ever so much for the very kind words...you don't know how much I appreciate that!
Yes, the 45-85 zoom is excellent, especially between 45-65mm, where beyond that, it does show a small increase in softness but still very usable.
There are a number of ways to AF fine tune a Pentax FA lens on the 645D...of course all tripod mounted. In one of the sub menus on the 645D you will come across Af fine tune setting. I don't have the 645D in front of me but from what I recall, press "OK" when you get to that menu setting and it will allow you to move a slider from -10, thru zero and continue up to +10. You can use any setting between -10 and +10.
To begin with, I take a test shot with one of the fixed focal length Autofocus lenses at a mid distance subject at the -10, -5, 0, +5, +10 settings and examine each file on your computer at 100%. You will notice in most cases that one of these AF fine tune settings is superior to the rest. Sometimes its close and sometimes not. Once I narrow down which setting gives the best degree of sharpness (I examine both center and sides of the frame), I then take a few test shots on either side of this AF fine tune setting to get a precise numerical setting I will use with a particular sample of a lens.
Each sample of the same lens can often result in a very different settings for each.
Zooms are a bit different as I often test at both the wide and long ends of a zoom and at a middle focal length setting. Then I determine best AF fine tune setting at each zoom setting and pick the AF fine tune setting that best represents most of the zoom range.
This is all easier done in practice than my explaining it with the written word.
I'm sometimes in PA. and maybe one day I'll will swing by LBI.
Last edited by D&A; 19th August 2013 at 12:11.
Thanks again for the explanation. Please if on LBI get in touch with me. Not only can I show you my favorite photo spots, we could lift a glass or three of your favorite beverage (ours is Pinot Grigio), but we have everything. Keep your informative posts coming!
That's very kind of you Dave and would look forward to it...Pinot Grigio is just fine! The question is how much will my photography be improved after a glass or three
Dave with regards to AF fine tuning a lens with the 645D, sometimes it's made a small degree of difference while at other times it's been substantial. It greatly depends on not only on the particular focal length length or type of lens being used, but more often on how well (or not so well) the lens was calibrated when it left the Pentax factory during the film era days. Both variables are important.
For example, I was testing two samples of a 300 f5.6 lens on the 645D (after I posted my comprehensive lens testing) where one sample barely needed a +1 setting, while the other 300 f5.6 needed a +9 AF fine tune setting, just to get in the same ballpark in terms of performance as the 1st sample. These differences between the two lenses of course was most readily seen when identical files from both lenses were examined at 100% on the computer monitor.
Maybe what would be both fun and instructional to start with is to take for example your FA 400 5.6 set up on a tripod and focus on a stationary subject at mid-distance and take three shots. One with AF fine tuning set to -10, one shot with it set to zero and a third shot set to +10 and then go back and examine all three files at 100% (actual pixels) and determine if you observe any differences in terms of sharpness of the test subject you focused on.
I've been reading your back and forths re: 645 lenses with great interest. I've been using the 55, 120 macro, 200/4 and 300/4 (645 > K adapter) with the 5IIs...results have been pleasing but great strain on focusing eye after cataract surgery. Will post examples if there is some interest.
Dave in NJ
Dave (D&A): do you fine tune with the lens wide open ( limiting depth of field) , or do you test stopped down to an aperature which you would be likely to use in the field? Thanks as always.
Dave in NJ
I too am right handed but left eye dominant and always focus with my left eye.
With regards to your question, I always first AF fine tune a lens wide open where the resulting depth of field is smallest. Sometimes after accomplishing this, I might repeat again but with the lens stopped down by a single f-stop. The reason being is that some lenses might have inherent softness when shot wide open and it's sometimes difficult to decern what and how much effect the AF fine tune is having.
Additonally although some might set the lens and focus on a subject at minimum focus distance, I have often found that sometime the greatest differences seen in Af fine tuning is at approx mid distance range. Let us know how it goes Dave. Thanks!
I am a hobbyist and recently acquired a pre-owned Pentax 645D. Previously I used D700/D800 with Zeiss and Leica-R lenses. I wanted to try out the medium format and hence made the switch. A couple of shots...
645D 90mm 1/200 @ f11 ISO200
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Tom, there seems to be speculation that manufacturers weaken the Bayer filters on the sensor to improve noise and high ISO. That with different color processing and interpolation could give that result. BTW, were the temperature and tint values the same in ACR? If not, I would make those the same and then see the difference. Sensels, whether on a CCD or CMOS, are color blind.
I really like the color in the 645D. Color is one thing Kodak did very well.
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Welcome Jamgolf. You will find most Pentax 645D shooters posting in the medium format section of the forum in the Fun with MF thread. If you find this thread lonely, please go there.
Welcome Jamgolf and enjoy your 645D!
Tom even looking at these web resolution images, I can plainly see the superiority of the 645D and not just in color/tonality but that certainly is its strong suit. Whether its CCD vs. CMOS I honestly can't say but images right out of the 645D never fails to impress me. This is much akin to images coming right out of the M9. I cannot say this about most other digital cameras I use. Both CCD of course so I'll let others come to their own conclusions.
The 45-85mm zoom never ceases to amaze me. Below is a shot of the I.M. Pei designed library at SUNY Fredonia at 65mm. The crop gives some indication of the sharpness of this lens. Jpeg/Flicker has removed the jaggies, but the edge of the antenna is never more than 1-2 pixels in width.
_IGP9556-Recovered copy by tsjanik47, on Flickr
_IGP9556-Recovered copycrop by tsjanik47, on Flickr
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Nice Tom! I've always been interested in the architecture of I.M. Pei . As for the 45-85 645 zoom, it too never ceases to amaze me with it's excellent performance, even though it's a tiny bit weaker on the long end. Think how relatively little this zoom can be had for compared to newly released Pentax 645 lenses. All one has to do on a damp rainy day is throw over it a plastic bag or two and you even turn it into a weather resistant lenses...LOL!
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First post in this thread. Australia capital at night.
645D + DFA25mm/4.
I know that this is an old thread and that most people post in the "fun with MF" thread now.
I also know that this was most helpful when I was researching my new camera choice and I would like to contribute to it.
Pentax 645D - 55mm AW
CPL + 10 stop ND
Stop chasing gear, start chasing photos instead.
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